scsi: storvsc: Fix ring buffer size calculation

Current code uses the specified ring buffer size (either the default of 128
Kbytes or a module parameter specified value) to encompass the one page
ring buffer header plus the actual ring itself. When the page size is 4K,
carving off one page for the header isn't significant. But when the page
size is 64K on ARM64, only half of the default 128 Kbytes is left for the
actual ring. While this doesn't break anything, the smaller ring size
could be a performance bottleneck.

Fix this by applying the VMBUS_RING_SIZE macro to the specified ring buffer
size. This macro adds a page for the header, and rounds up the size to a
page boundary, using the page size for which the kernel is built. Use this
new size for subsequent ring buffer calculations. For example, on ARM64
with 64K page size and the default ring size, this results in the actual
ring being 128 Kbytes, which is intended.

Cc: stable@vger.kernel.org # 5.15.x
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Link: https://lore.kernel.org/r/20240122170956.496436-1-mhklinux@outlook.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Improve type safety of scsi_rescan_device()

Most callers of scsi_rescan_device() have the scsi_device pointer readily
available. Pass a struct scsi_device pointer to scsi_rescan_device()
instead of a struct device pointer. This change prevents that a pointer to
another struct device would be passed accidentally to scsi_rescan_device().

Remove the scsi_rescan_device() declaration from the scsi_priv.h header
file since it duplicates the declaration in <scsi/scsi_host.h>.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230822153043.4046244-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Handle additional SRB status values

Testing of virtual Fibre Channel devices under Hyper-V has shown additional
SRB status values being returned for various error cases. Because these
SRB status values are not recognized by storvsc, the I/O operations are not
flagged as an error. Requests are treated as if they completed normally but
with zero data transferred, which can cause a flood of retries.

Add definitions for these SRB status values and handle them like other
error statuses from the Hyper-V host.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1692984084-95105-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix handling of virtual Fibre Channel timeouts

Hyper-V provides the ability to connect Fibre Channel LUNs to the host
system and present them in a guest VM as a SCSI device. I/O to the vFC
device is handled by the storvsc driver. The storvsc driver includes a
partial integration with the FC transport implemented in the generic
portion of the Linux SCSI subsystem so that FC attributes can be displayed
in /sys. However, the partial integration means that some aspects of vFC
don't work properly. Unfortunately, a full and correct integration isn't
practical because of limitations in what Hyper-V provides to the guest.

In particular, in the context of Hyper-V storvsc, the FC transport timeout
function fc_eh_timed_out() causes a kernel panic because it can't find the
rport and dereferences a NULL pointer. The original patch that added the
call from storvsc_eh_timed_out() to fc_eh_timed_out() is faulty in this
regard.

In many cases a timeout is due to a transient condition, so the situation
can be improved by just continuing to wait like with other I/O requests
issued by storvsc, and avoiding the guaranteed panic. For a permanent
failure, continuing to wait may result in a hung thread instead of a panic,
which again may be better.

So fix the panic by removing the storvsc call to fc_eh_timed_out(). This
allows storvsc to keep waiting for a response. The change has been tested
by users who experienced a panic in fc_eh_timed_out() due to transient
timeouts, and it solves their problem.

In the future we may want to deprecate the vFC functionality in storvsc
since it can't be fully fixed. But it has current users for whom it is
working well enough, so it should probably stay for a while longer.

Fixes: 3930d7309807 ("scsi: storvsc: use default I/O timeout handler for FC devices")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1690606764-79669-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Limit max_sectors for virtual Fibre Channel devices

The Hyper-V host is queried to get the max transfer size that it supports,
and this value is used to set max_sectors for the synthetic SCSI
controller. However, this max transfer size may be too large for virtual
Fibre Channel devices, which are limited to 512 Kbytes. If a larger
transfer size is used with a vFC device, Hyper-V always returns an error,
and storvsc logs a message like this where the SRB status and SCSI status
are both zero:

hv_storvsc <GUID>: tag#197 cmd 0x8a status: scsi 0x0 srb 0x0 hv 0xc0000001

Add logic to limit the max transfer size to 512 Kbytes for vFC devices.

Fixes: 1d3e0980782f ("scsi: storvsc: Correct reporting of Hyper-V I/O size limits")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1689887102-32806-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Handle SRB status value 0x30

In response to a disk I/O request, Hyper-V has been observed to return SRB
status value 0x30. This indicates the request was not processed by Hyper-V
because low memory conditions on the host caused an internal error. The
0x30 status is not recognized by storvsc, so the I/O operation is not
flagged as an error. The request is treated as if it completed normally but
with zero data transferred, causing a flood of retries.

Add a definition for this SRB status value and handle it like other error
statuses from the Hyper-V host.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1688788886-94279-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Always set no_report_opcodes

Hyper-V synthetic SCSI devices do not support the MAINTENANCE_IN SCSI
command, so scsi_report_opcode() always fails, resulting in messages like
this:

hv_storvsc <guid>: tag#205 cmd 0xa3 status: scsi 0x2 srb 0x86 hv 0xc0000001

The recently added support for command duration limits calls
scsi_report_opcode() four times as each device comes online, which
significantly increases the number of messages logged in a system with many
disks.

Fix the problem by always marking Hyper-V synthetic SCSI devices as not
supporting scsi_report_opcode(). With this setting, the MAINTENANCE_IN SCSI
command is not issued and no messages are logged.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1686343101-18930-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Don't pass unused PFNs to Hyper-V host

In a SCSI request, storvsc pre-allocates space for up to
MAX_PAGE_BUFFER_COUNT physical frame numbers to be passed to Hyper-V. If
the size of the I/O request requires more PFNs, a separate memory area of
exactly the correct size is dynamically allocated.

But when the pre-allocated area is used, current code always passes
MAX_PAGE_BUFFER_COUNT PFNs to Hyper-V, even if fewer are needed. While
this doesn't break anything because the additional PFNs are always zero,
more bytes than necessary are copied into the VMBus channel ring buffer.
This takes CPU cycles and wastes space in the ring buffer. For a typical 4
Kbyte I/O that requires only a single PFN, 248 unnecessary bytes are
copied.

Fix this by setting the payload_sz based on the actual number of PFNs
required, not the size of the pre-allocated space.

Reported-by: John Starks <jostarks@microsoft.com>
Fixes: 8f43710543ef ("scsi: storvsc: Support PAGE_SIZE larger than 4K")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1684171241-16209-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Handle BlockSize change in Hyper-V VHD/VHDX file

Hyper-V uses a VHD or VHDX file on the host as the underlying storage for a
virtual disk. The VHD/VHDX file format is a sparse format where real disk
space on the host is assigned in chunks that the VHD/VHDX file format calls
the BlockSize. This BlockSize is not to be confused with the 512-byte (or
4096-byte) sector size of the underlying storage device. The default block
size for a new VHD/VHDX file is 32 Mbytes. When a guest VM touches any
disk space within a 32 Mbyte chunk of the VHD/VHDX file, Hyper-V allocates
32 Mbytes of real disk space for that section of the VHD/VHDX. Similarly,
if a discard operation is done that covers an entire 32 Mbyte chunk,
Hyper-V will free the real disk space for that portion of the VHD/VHDX.
This BlockSize is surfaced in Linux as the "discard_granularity" in
/sys/block/sd<x>/queue, which makes sense.

Hyper-V also has differencing disks that can overlay a VHD/VHDX file to
capture changes to the VHD/VHDX while preserving the original VHD/VHDX.
One example of this differencing functionality is for VM snapshots. When a
snapshot is created, a differencing disk is created. If the snapshot is
rolled back, Hyper-V can just delete the differencing disk, and the VM will
see the original disk contents at the time the snapshot was taken.
Differencing disks are used in other scenarios as well.

The BlockSize for a differencing disk defaults to 2 Mbytes, not 32 Mbytes.
The smaller default is used because changes to differencing disks are
typically scattered all over, and Hyper-V doesn't want to allocate 32
Mbytes of real disk space for a stray write here or there. The smaller
BlockSize provides more efficient use of real disk space.

When a differencing disk is added to a VHD/VHDX, Hyper-V reports
UNIT_ATTENTION with a sense code indicating "Operating parameters have
changed", because the value of discard_granularity should be changed to 2
Mbytes. When the differencing disk is removed, discard_granularity should
be changed back to 32 Mbytes. However, current code simply reports a
message from scsi_report_sense() and the value of
/sys/block/sd<x>/queue/discard_granularity is not updated. The message
isn't very actionable by a sysadmin.

Fix this by having the storvsc driver check for the sense code indicating
that the underly VHD/VHDX block size has changed, and do a rescan of the
device to pick up the new discard_granularity. With this change the entire
transition to/from differencing disks is handled automatically and
transparently, with no confusing messages being output.

Link: https://lore.kernel.org/r/1677516514-86060-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Drivers: hv: Make remove callback of hyperv driver void returned

Since commit fc7a6209d571 ("bus: Make remove callback return
void") forces bus_type::remove be void-returned, it doesn't
make much sense for any bus based driver implementing remove
callbalk to return non-void to its caller.

As such, change the remove function for Hyper-V VMBus based
drivers to return void.

Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Link: https://lore.kernel.org/r/TYCP286MB2323A93C55526E4DF239D3ACCAFA9@TYCP286MB2323.JPNP286.PROD.OUTLOOK.COM
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Fix swiotlb bounce buffer leak in confidential VM

storvsc_queuecommand() maps the scatter/gather list using scsi_dma_map(),
which in a confidential VM allocates swiotlb bounce buffers. If the I/O
submission fails in storvsc_do_io(), the I/O is typically retried by higher
level code, but the bounce buffer memory is never freed. The mostly like
cause of I/O submission failure is a full VMBus channel ring buffer, which
is not uncommon under high I/O loads. Eventually enough bounce buffer
memory leaks that the confidential VM can't do any I/O. The same problem
can arise in a non-confidential VM with kernel boot parameter
swiotlb=force.

Fix this by doing scsi_dma_unmap() in the case of an I/O submission
error, which frees the bounce buffer memory.

Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for storvsc driver")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1670183564-76254-1-git-send-email-mikelley@microsoft.com
Tested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Change the return type of .eh_timed_out()

Commit 6600593cbd93 ("block: rename BLK_EH_NOT_HANDLED to BLK_EH_DONE")
made it impossible for .eh_timed_out() implementations to call
scsi_done() without causing a crash.

Restore support for SCSI timeout handlers to call scsi_done() as follows:

* Change all .eh_timed_out() handlers as follows:

- Change the return type into enum scsi_timeout_action.
- Change BLK_EH_RESET_TIMER into SCSI_EH_RESET_TIMER.
- Change BLK_EH_DONE into SCSI_EH_NOT_HANDLED.

* In scsi_timeout(), convert the SCSI_EH_* values into BLK_EH_* values.

Reviewed-by: Lee Duncan <lduncan@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221018202958.1902564-3-bvanassche@acm.org
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix handling of srb_status and capacity change events

Current handling of the srb_status is incorrect. Commit 52e1b3b3daa9
("scsi: storvsc: Correctly handle multiple flags in srb_status")
is based on srb_status being a set of flags, when in fact only the
2 high order bits are flags and the remaining 6 bits are an integer
status. Because the integer values of interest mostly look like flags,
the code actually works when treated that way.

But in the interest of correctness going forward, fix this by treating
the low 6 bits of srb_status as an integer status code. Add handling
for SRB_STATUS_INVALID_REQUEST, which was the original intent of commit
52e1b3b3daa9. Furthermore, treat the ERROR, ABORTED, and INVALID_REQUEST
srb status codes as essentially equivalent for the cases we care about.
There's no harm in doing so, and it isn't always clear which status code
current or older versions of Hyper-V report for particular conditions.

Treating the srb status codes as equivalent has the additional benefit
of ensuring that capacity change events result in an immediate rescan
so that the new size is known to Linux. Existing code checks SCSI
sense data for capacity change events when the srb status is ABORTED.
But capacity change events are also being observed when Hyper-V reports
the srb status as ERROR. Without the immediate rescan, the new size
isn't known until something else causes a rescan (such as running
fdisk to expand a partition), and in the meantime, tools such as "lsblk"
continue to report the old size.

Fixes: 52e1b3b3daa9 ("scsi: storvsc: Correctly handle multiple flags in srb_status")
Reported-by: Juan Tian <juantian@microsoft.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1668019722-1983-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: remove an extraneous "to" in a comment

Signed-off-by: wangjianli <wangjianli@cdjrlc.com>
Link: https://lore.kernel.org/r/20220908130754.34999-1-wangjianli@cdjrlc.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Drivers: hv: vmbus: Optimize vmbus_on_event

In the vmbus_on_event loop, 2 jiffies timer will not serve the purpose if
callback_fn takes longer. For effective use move this check inside of
callback functions where needed. Out of all the VMbus drivers using
vmbus_on_event, only storvsc has a high packet volume, thus add this limit
only in storvsc callback for now.
There is no apparent benefit of loop itself because this tasklet will be
scheduled anyway again if there are packets left in ring buffer. This
patch removes this unnecessary loop as well.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1658741848-4210-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Drop DID_TARGET_FAILURE use

DID_TARGET_FAILURE is internal to the SCSI layer. Drivers must not use it
because:

1. It's not propagated upwards, so SG IO/passthrough users will not see an
error and think a command was successful.

2. There is no handling for it in scsi_decide_disposition() so it results
in the SCSI error handling running.

It looks like the driver wanted a hard failure so swap it with
DID_BAD_TARGET.

Link: https://lore.kernel.org/r/20220812010027.8251-3-michael.christie@oracle.com
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq

storvsc_error_wq workqueue should not be marked as WQ_MEM_RECLAIM as it
doesn't need to make forward progress under memory pressure. Marking this
workqueue as WQ_MEM_RECLAIM may cause deadlock while flushing a
non-WQ_MEM_RECLAIM workqueue. In the current state it causes the following
warning:

[ 14.506347] ------------[ cut here ]------------
[ 14.506354] workqueue: WQ_MEM_RECLAIM storvsc_error_wq_0:storvsc_remove_lun is flushing !WQ_MEM_RECLAIM events_freezable_power_:disk_events_workfn
[ 14.506360] WARNING: CPU: 0 PID: 8 at <-snip->kernel/workqueue.c:2623 check_flush_dependency+0xb5/0x130
[ 14.506390] CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.4.0-1086-azure #91~18.04.1-Ubuntu
[ 14.506391] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 05/09/2022
[ 14.506393] Workqueue: storvsc_error_wq_0 storvsc_remove_lun
[ 14.506395] RIP: 0010:check_flush_dependency+0xb5/0x130
<-snip->
[ 14.506408] Call Trace:
[ 14.506412] __flush_work+0xf1/0x1c0
[ 14.506414] __cancel_work_timer+0x12f/0x1b0
[ 14.506417] ? kernfs_put+0xf0/0x190
[ 14.506418] cancel_delayed_work_sync+0x13/0x20
[ 14.506420] disk_block_events+0x78/0x80
[ 14.506421] del_gendisk+0x3d/0x2f0
[ 14.506423] sr_remove+0x28/0x70
[ 14.506427] device_release_driver_internal+0xef/0x1c0
[ 14.506428] device_release_driver+0x12/0x20
[ 14.506429] bus_remove_device+0xe1/0x150
[ 14.506431] device_del+0x167/0x380
[ 14.506432] __scsi_remove_device+0x11d/0x150
[ 14.506433] scsi_remove_device+0x26/0x40
[ 14.506434] storvsc_remove_lun+0x40/0x60
[ 14.506436] process_one_work+0x209/0x400
[ 14.506437] worker_thread+0x34/0x400
[ 14.506439] kthread+0x121/0x140
[ 14.506440] ? process_one_work+0x400/0x400
[ 14.506441] ? kthread_park+0x90/0x90
[ 14.506443] ret_from_fork+0x35/0x40
[ 14.506445] ---[ end trace 2d9633159fdc6ee7 ]---

Link: https://lore.kernel.org/r/1659628534-17539-1-git-send-email-ssengar@linux.microsoft.com
Fixes: 436ad9413353 ("scsi: storvsc: Allow only one remove lun work item to be issued per lun")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Correct reporting of Hyper-V I/O size limits

Current code is based on the idea that the max number of SGL entries
also determines the max size of an I/O request. While this idea was
true in older versions of the storvsc driver when SGL entry length
was limited to 4 Kbytes, commit 3d9c3dcc58e9 ("scsi: storvsc: Enable
scatterlist entry lengths > 4Kbytes") removed that limitation. It's
now theoretically possible for the block layer to send requests that
exceed the maximum size supported by Hyper-V. This problem doesn't
currently happen in practice because the block layer defaults to a
512 Kbyte maximum, while Hyper-V in Azure supports 2 Mbyte I/O sizes.
But some future configuration of Hyper-V could have a smaller max I/O
size, and the block layer could exceed that max.

Fix this by correctly setting max_sectors as well as sg_tablesize to
reflect the maximum I/O size that Hyper-V reports. While allowing
I/O sizes larger than the block layer default of 512 Kbytes doesn’t
provide any noticeable performance benefit in the tests we ran, it's
still appropriate to report the correct underlying Hyper-V capabilities
to the Linux block layer.

Also tweak the virt_boundary_mask to reflect that the required
alignment derives from Hyper-V communication using a 4 Kbyte page size,
and not on the guest page size, which might be bigger (eg. ARM64).

Link: https://lore.kernel.org/r/1655190355-28722-1-git-send-email-ssengar@linux.microsoft.com
Fixes: 3d9c3dcc58e9 ("scsi: storvsc: Enable scatter list entry lengths > 4Kbytes")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix typo in comment

Spelling mistake (triple letters) in comment. Detected with the help of
Coccinelle.

Link: https://lore.kernel.org/r/20220521111145.81697-12-Julia.Lawall@inria.fr
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Removing Pre Win8 related logic

The latest storvsc code has already removed the support for windows 7 and
earlier. There is still some code logic remaining which is there to support
pre Windows 8 OS. This patch removes these stale logic.
This patch majorly does three things :

1. Removes vmscsi_size_delta and its logic, as the vmscsi_request struct is
same for all the OS post windows 8 there is no need of delta.
2. Simplify sense_buffer_size logic, as there is single buffer size for
all the post windows 8 OS.
3. Embed the vmscsi_win8_extension structure inside the vmscsi_request,
as there is no separate handling required for different OS.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1653478022-26621-1-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Remove support for Hyper-V 2008 and 2008R2/Win7

The storvsc driver has special case code for running on the first released
versions of Hyper-V: 2008 and 2008 R2/Windows 7. These versions are now
out of support (except for extended security updates) and lack support
for performance features like multiple VMbus channels that are needed for
effective production usage of Linux guests.

The negotiation of the VMbus protocol versions required by these old
Hyper-V versions has been removed from the VMbus driver. So now remove
the handling of these VMbus protocol versions from the storvsc driver.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/1651509391-2058-3-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Fix storvsc_queuecommand() memory leak

Fix possible memory leak in error path of storvsc_queuecommand() when
DMA mapping fails.

Signed-off-by: Juan Vazquez <juvazq@linux.microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20220109001758.6401-1-juvazq@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Fix unsigned comparison to zero

The unsigned variable sg_count is being assigned a return value
from the call to scsi_dma_map() that can return -ENOMEM.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211227040311.54584-1-yuehaibing@huawei.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Add Isolation VM support for storvsc driver

In Isolation VM, all shared memory with host needs to mark visible
to host via hvcall. vmbus_establish_gpadl() has already done it for
storvsc rx/tx ring buffer. The page buffer used by vmbus_sendpacket_
mpb_desc() still needs to be handled. Use DMA API(scsi_dma_map/unmap)
to map these memory during sending/receiving packet and return swiotlb
bounce buffer dma address. In Isolation VM, swiotlb bounce buffer is
marked to be visible to host and the swiotlb force mode is enabled.

Set device's dma min align mask to HV_HYP_PAGE_SIZE - 1 in order to
keep the original data offset in the bounce buffer.

Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211213071407.314309-5-ltykernel@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc_drv: Call scsi_done() directly

Conditional statements are faster than indirect calls. Hence call
scsi_done() directly.

Link: https://lore.kernel.org/r/20211007202923.2174984-74-bvanassche@acm.org
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix validation for unsolicited incoming packets

The validation on the length of incoming packets performed in
storvsc_on_channel_callback() does not apply to unsolicited packets with ID
of 0 sent by Hyper-V. Adjust the validation for such unsolicited packets.

Link: https://lore.kernel.org/r/20211007122828.469289-1-parri.andrea@gmail.com
Fixes: 91b1b640b834b2 ("scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()")
Reported-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Log TEST_UNIT_READY errors as warnings

Commit 08f76547f08d ("scsi: storvsc: Update error logging") added more
robust logging of errors, particularly those reported as Hyper-V
errors. But this change produces extra logging noise in that
TEST_UNIT_READY may report errors during the normal course of detecting
device adds and removes.

Fix this by logging TEST_UNIT_READY errors as warnings, so that log lines
are produced only if the storvsc log level is changed to WARN level on the
kernel boot line.

Link: https://lore.kernel.org/r/1628269970-87876-1-git-send-email-mikelley@microsoft.com
Fixes: 08f76547f08d ("scsi: storvsc: Update error logging")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Correctly handle multiple flags in srb_status

Hyper-V is observed to sometimes set multiple flags in the srb_status, such
as ABORTED and ERROR. Current code in storvsc_handle_error() handles only a
single flag being set, and does nothing when multiple flags are set. Fix
this by changing the case statement into a series of "if" statements
testing individual flags. The functionality for handling each flag is
unchanged.

Link: https://lore.kernel.org/r/1622827263-12516-3-git-send-email-mikelley@microsoft.com
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Update error logging

When an I/O error is reported by the underlying Hyper-V host, current code
provides details only when the logging level is set to WARN, making it more
difficult to diagnose problems in live customer situations. Fix this by
reporting details at ERROR level, which is the default. Also add more
information, including the Hyper-V error code, and the tag # so that the
message can be matched with messages at the SCSI and blk-mq levels.

Also, sense information logging is inconsistent and duplicative. The
existence of sense info is first logged at WARN level, and then full sense
info is logged at ERROR level. Fix this by removing the logging of the
existence of sense info, and change the logging of full sense info to WARN
level in favor of letting the generic SCSI layer handle such logging. With
the change to WARN level, it's no longer necessary to filter out as noise
any NOT READY sense info generated by the virtual DVD device.

Link: https://lore.kernel.org/r/1622827263-12516-2-git-send-email-mikelley@microsoft.com
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Miscellaneous code cleanups

As general cleanup and in preparation for subsequent patches:

- Use min() instead of open coding.

- Use set_host_byte() instead of open coding access to scsi_status
field.

- Collapse nested "if" statements to reduce indentation.

- Fix other indentation.

- Remove extra blank lines.

No functional changes.

[mkp: dropped status_byte() which no longer exists]

Link: https://lore.kernel.org/r/1622827263-12516-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Use blk_mq_unique_tag() to generate requestIDs

Use blk_mq_unique_tag() to generate requestIDs for StorVSC, avoiding
all issues with allocating enough entries in the VMbus requestor.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20210510210841.370472-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer

Pointers to ring-buffer packets sent by Hyper-V are used within the
guest VM. Hyper-V can send packets with erroneous values or modify
packet fields after they are processed by the guest. To defend
against these scenarios, return a copy of the incoming VMBus packet
after validating its length and offset fields in hv_pkt_iter_first().
In this way, the packet can no longer be modified by the host.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210408161439.341988-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Enable scatterlist entry lengths > 4Kbytes

storvsc currently sets .dma_boundary to limit scatterlist entries to 4
Kbytes, which is less efficient with huge pages that offer large chunks of
contiguous physical memory. Improve the algorithm for creating the Hyper-V
guest physical address PFN array so that scatterlist entries with lengths >
4Kbytes are handled. As a result, remove the .dma_boundary setting.

The improved algorithm also adds support for scatterlist entries with
offsets >= 4Kbytes, which is supported by many other SCSI low-level
drivers. And it retains support for architectures where possibly PAGE_SIZE
!= HV_HYP_PAGE_SIZE (such as ARM64).

Link: https://lore.kernel.org/r/1614120294-1930-1-git-send-email-mikelley@microsoft.com
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Parameterize number hardware queues

Add ability to set the number of hardware queues with new module parameter,
storvsc_max_hw_queues. The default value remains the number of CPUs. This
functionality is useful in some environments (e.g. Microsoft Azure) where
decreasing the number of hardware queues has been shown to improve
performance.

Link: https://lore.kernel.org/r/20210224232948.4651-1-melanieplageman@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Melanie Plageman (Microsoft) <melanieplageman@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Return DID_ERROR for invalid commands

ILLEGAL_COMMAND is a sense code, not a driver byte.

Link: https://lore.kernel.org/r/20210113090500.129644-33-hare@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()

Check that the packet is of the expected size at least, don't copy data
past the packet.

Link: https://lore.kernel.org/r/20201217203321.4539-4-parri.andrea@gmail.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Reported-by: Saruhan Karademir <skarade@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Resolve data race in storvsc_probe()

vmscsi_size_delta can be written concurrently by multiple instances of
storvsc_probe(), corresponding to multiple synthetic IDE/SCSI devices;
cf. storvsc_drv's probe_type == PROBE_PREFER_ASYNCHRONOUS. Change the
global variable vmscsi_size_delta to per-synthetic-IDE/SCSI-device.

Link: https://lore.kernel.org/r/20201217203321.4539-3-parri.andrea@gmail.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Suggested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix max_outstanding_req_per_channel for Win8 and newer

Current code overestimates the value of max_outstanding_req_per_channel for
Win8 and newer hosts, since vmscsi_size_delta is set to the initial value
of sizeof(vmscsi_win8_extension) rather than zero. This may lead to wrong
decisions when using ring_avail_percent_lowater equals to zero. The
estimate of max_outstanding_req_per_channel is 'exact' for Win7 and older
hosts. A better choice, keeping the algorithm for the estimation simple,
is to err the other way around, i.e., to underestimate for Win7 and older
but to use the exact value for Win8 and newer.

Link: https://lore.kernel.org/r/20201217203321.4539-2-parri.andrea@gmail.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Suggested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"

This reverts commit a8c3209998afb5c4941b49e35b513cea9050cb4a.

It is reported that the said commit caused regression in netvsc.

Reported-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer

Pointers to ring-buffer packets sent by Hyper-V are used within the
guest VM. Hyper-V can send packets with erroneous values or modify
packet fields after they are processed by the guest. To defend
against these scenarios, return a copy of the incoming VMBus packet
after validating its length and offset fields in hv_pkt_iter_first().
In this way, the packet can no longer be modified by the host.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201208045311.10244-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Revert "scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()"

This reverts commit 3b8c72d076c42bf27284cda7b2b2b522810686f8.

Dexuan reported a regression where StorVSC fails to probe a device (and
where, consequently, the VM may fail to boot). The root-cause analysis led
to a long-standing race condition that is exposed by the validation /commit
in question. Let's put the new validation aside until a proper solution
for that race condition is in place.

Link: https://lore.kernel.org/r/20201211131404.21359-1-parri.andrea@gmail.com
Fixes: 3b8c72d076c4 ("scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()")
Cc: Dexuan Cui <decui@microsoft.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback()

Check that the packet is of the expected size at least, don't copy data
past the packet.

Link: https://lore.kernel.org/r/20201118145348.109879-1-parri.andrea@gmail.com
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Reported-by: Saruhan Karademir <skarade@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix error return in storvsc_probe()

Return -ENOMEM from the error handling case instead of 0.

Link: https://lore.kernel.org/r/20201127030206.104616-1-jingxiangfeng@huawei.com
Fixes: 436ad9413353 ("scsi: storvsc: Allow only one remove lun work item to be issued per lun")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening

Currently, pointers to guest memory are passed to Hyper-V as
transaction IDs in storvsc. In the face of errors or malicious
behavior in Hyper-V, storvsc should not expose or trust the transaction
IDs returned by Hyper-V to be valid guest memory addresses. Instead,
use small integers generated by vmbus_requestor as requests
(transaction) IDs.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Link: https://lore.kernel.org/r/20201109100402.8946-3-parri.andrea@gmail.com
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Support PAGE_SIZE larger than 4K

Hyper-V always use 4k page size (HV_HYP_PAGE_SIZE), so when
communicating with Hyper-V, a guest should always use HV_HYP_PAGE_SIZE
as the unit for page related data. For storvsc, the data is
vmbus_packet_mpb_array. And since in scsi_cmnd, sglist of pages (in unit
of PAGE_SIZE) is used, we need convert pages in the sglist of scsi_cmnd
into Hyper-V pages in vmbus_packet_mpb_array.

This patch does the conversion by dividing pages in sglist into Hyper-V
pages, offset and indexes in vmbus_packet_mpb_array are recalculated
accordingly.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-12-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Add validation for untrusted Hyper-V values

For additional robustness in the face of Hyper-V errors or malicious
behavior, validate all values that originate from packets that Hyper-V has
sent to the guest. Ensure that invalid values cannot cause data being
copied out of the bounds of the source buffer when calling memcpy. Ensure
that outgoing packets do not have any leftover guest memory that has not
been zeroed out.

Link: https://lore.kernel.org/r/20200706160928.53049-1-lkmlabelt@gmail.com
Cc: James E.J. Bottomley <jejb@linux.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix spelling mistake

Fix typo: "trigerred" --> "triggered"

Link: https://lore.kernel.org/r/20200624135600.14274-1-f.suligoi@asem.it
Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Introduce the per-storvsc_device spinlock

storvsc uses the spinlock of the hv_device's primary channel to
serialize modifications of stor_chns[] performed by storvsc_do_io()
and storvsc_change_target_cpu(), when it could/should use a (per-)
storvsc_device spinlock: this change untangles the synchronization
mechanism for the (storvsc-specific) stor_chns[] array from the
"generic" VMBus code and data structures, clarifying the scope of
this synchronization mechanism.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-8-parri.andrea@gmail.com
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Remove memset before memory freeing in storvsc_suspend()

Remove memset with 0 for stor_device->stor_chns in storvsc_suspend() before
the call to kfree() as the memory contains no sensitive information.

Link: https://lore.kernel.org/r/20200605075934.8403-1-efremov@linux.com
Fixes: 56fb10585934 ("scsi: storvsc: Add the support of hibernation")
Suggested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned

For each storvsc_device, storvsc keeps track of the channel target CPUs
associated to the device (alloced_cpus) and it uses this information to
fill a "cache" (stor_chns) mapping CPU->channel according to a certain
heuristic. Update the alloced_cpus mask and the stor_chns array when a
channel of the storvsc device is re-assigned to a different CPU.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>
Link: https://lore.kernel.org/r/20200406001514.19876-12-parri.andrea@gmail.com
Reviewed-by; Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
[ wei: fix a small issue reported by kbuild test robot <lkp@intel.com> ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>

scsi: storvsc: Correctly set number of hardware queues for IDE disk

Commit 0ed881027690 ("scsi: storvsc: setup 1:1 mapping between hardware
queue and CPU queue") introduced a regression for disks attached to
IDE. For these disks the host VSP only offers one VMBUS channel. Setting
multiple queues can overload the VMBUS channel and result in performance
drop for high queue depth workload on system with large number of CPUs.

Fix it by leaving the number of hardware queues to 1 (default value) for
IDE disks.

Fixes: 0ed881027690 ("scsi: storvsc: setup 1:1 mapping between hardware queue and CPU queue")
Link: https://lore.kernel.org/r/1578960516-108228-1-git-send-email-longli@linuxonhyperv.com
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Add the support of hibernation

When we're in storvsc_suspend(), we're sure the SCSI layer has quiesced the
scsi device by scsi_bus_suspend() -> ... -> scsi_device_quiesce(), so the
low level SCSI adapter driver only needs to suspend/resume its own state.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

scsi: storvsc: setup 1:1 mapping between hardware queue and CPU queue

storvsc doesn't use a dedicated hardware queue for a given CPU queue. When
issuing I/O, it selects returning CPU (hardware queue) dynamically based on
vmbus channel usage across all channels.

This patch advertises num_present_cpus() as number of hardware queues. This
will have upper layer setup 1:1 mapping between hardware queue and CPU
queue and avoid unnecessary locking when issuing I/O.

Link: https://lore.kernel.org/r/1567790660-48142-1-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: set virt_boundary_mask in the scsi host template

This ensures all proper DMA layer handling is taken care of by the SCSI
midlayer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Add ability to change scsi queue depth

Adding functionality to allow the SCSI queue depth to be changed by
utilizing the "scsi_change_queue_depth" function.

[mkp: checkpatch]

Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms and conditions of the gnu general public license
version 2 as published by the free software foundation this program
is distributed in the hope it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not write to the free
software foundation inc 59 temple place suite 330 boston ma 02111
1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 33 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: storvsc: Reduce default ring buffer size to 128 Kbytes

Reduce the default VMbus channel ring buffer size for storvsc SCSI devices
from 1 Mbyte to 128 Kbytes. Measurements show that ring buffer sizes above
128 Kbytes do not increase performance even at very high IOPS rates, so
don't waste the memory. Also remove the dependence on PAGE_SIZE, since the
ring buffer size should not change on architectures where PAGE_SIZE is not
4 Kbytes.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix calculation of sub-channel count

When the number of sub-channels offered by Hyper-V is >= the number of CPUs
in the VM, calculate the correct number of sub-channels. The current code
produces one too many.

This scenario arises only when the number of CPUs is artificially
restricted (for example, with maxcpus=<n> on the kernel boot line), because
Hyper-V normally offers a sub-channel count < number of CPUs. While the
current code doesn't break, the extra sub-channel is unbalanced across the
CPUs (for example, a total of 5 channels on a VM with 4 CPUs).

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: flip the default on use_clustering

Most SCSI drivers want to enable "clustering", that is merging of
segments so that they might span more than a single page. Remove the
ENABLE_CLUSTERING define, and require drivers to explicitly set
DISABLE_CLUSTERING to disable this feature.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix a race in sub-channel creation that can cause panic

We can concurrently try to open the same sub-channel from 2 paths:

path #1: vmbus_onoffer() -> vmbus_process_offer() -> handle_sc_creation().
path #2: storvsc_probe() -> storvsc_connect_to_vsp() ->
-> storvsc_channel_init() -> handle_multichannel_storage() ->
-> vmbus_are_subchannels_present() -> handle_sc_creation().

They conflict with each other, but it was not an issue before the recent
commit ae6935ed7d42 ("vmbus: split ring buffer allocation from open"),
because at the beginning of vmbus_open() we checked newchannel->state so
only one path could succeed, and the other would return with -EINVAL.

After ae6935ed7d42, the failing path frees the channel's ringbuffer by
vmbus_free_ring(), and this causes a panic later.

Commit ae6935ed7d42 itself is good, and it just reveals the longstanding
race. We can resolve the issue by removing path #2, i.e. removing the
second vmbus_are_subchannels_present() in handle_multichannel_storage().

BTW, the comment "Check to see if sub-channels have already been created"
in handle_multichannel_storage() is incorrect: when we unload the driver,
we first close the sub-channel(s) and then close the primary channel, next
the host sends rescind-offer message(s) so primary->sc_list will become
empty. This means the first vmbus_are_subchannels_present() in
handle_multichannel_storage() is never useful.

Fixes: ae6935ed7d42 ("vmbus: split ring buffer allocation from open")
Cc: stable@vger.kernel.org
Cc: Long Li <longli@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

use the new async probing feature for the hyperv drivers

Recent kernels support asynchronous probing; most hyperv drivers
can be probed async easily so set the required flag for this.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: storvsc: Avoid allocating memory for temp cpumasks

Current code allocates 240 Kbytes (in typical configs) for each synthetic
SCSI controller to use as temp cpumask variables. Recode to avoid needing
the temp cpumask variables and remove the memory allocation.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Select channel based on available percentage of ring buffer to write

This is a best effort for estimating on how busy the ring buffer is for
that channel, based on available buffer to write in percentage. It is
still possible that at the time of actual ring buffer write, the space
may not be available due to other processes may be writing at the time.

Selecting a channel based on how full it is can reduce the possibility
that a ring buffer write will fail, and avoid the situation a channel is
over busy.

Now it's possible that storvsc can use a smaller ring buffer size
(e.g. 40k bytes) to take advantage of cache locality.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Set up correct queue depth values for IDE devices

Unlike SCSI and FC, we don't use multiple channels for IDE. Also fix
the calculation for sub-channels.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storsvc: don't set a bounce limit

The default already is to never bounce, so the call is a no-op.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Spread interrupts when picking a channel for I/O requests

Update the algorithm in storvsc_do_io to look for a channel
starting with the current CPU + 1 and wrap around (within the
current NUMA node). This spreads VMbus interrupts more evenly
across CPUs. Previous code always started with first CPU in
the current NUMA node, skewing the interrupt load to that CPU.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Increase cmd_per_lun for higher speed devices

Increase cmd_per_lun to allow more I/Os in progress per device,
particularly for NVMe's. The Hyper-V host side can handle the higher
count with no issues.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: missing error code in storvsc_probe()

We should set the error code if fc_remote_port_add() fails.

Cc: <stable@vger.kernel.org> #v4.12+
Fixes: daf0cd445a21 ("scsi: storvsc: Add support for FC rport.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Cathy Avery <cavery@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix scsi_cmd error assignments in storvsc_handle_error

When an I/O is returned with an srb_status of SRB_STATUS_INVALID_LUN
which has zero good_bytes it must be assigned an error. Otherwise the
I/O will be continuously requeued and will cause a deadlock in the case
where disks are being hot added and removed. sd_probe_async will wait
forever for its I/O to complete while holding scsi_sd_probe_domain.

Also returning the default error of DID_TARGET_FAILURE causes multipath
to not retry the I/O resulting in applications receiving I/O errors
before a failover can occur.

Signed-off-by: Cathy Avery <cavery@redhat.com>
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Avoid excessive host scan on controller change

When there are multiple disks attached to the same SCSI controller, the
host may send several VSTOR_OPERATION_REMOVE_DEVICE or
VSTOR_OPERATION_ENUMERATE_BUS messages in a row, to indicate there is a
change on the SCSI controller. In response, storvsc rescans the SCSI
host.

There is no need to do multiple scans on the same host. Fix the code to
do only one scan.

[mkp: applied by hand]

Signed-off-by: Long Li <longli@microsoft.com>
Tested-by: Cathy Avery <cavery@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Allow only one remove lun work item to be issued per lun

When running multipath on a VM if all available paths go down the driver
can schedule large amounts of storvsc_remove_lun work items to the same
lun. In response to the failing paths typically storvsc responds by
taking host->scan_mutex and issuing a TUR per lun. If there has been
heavy IO to the failed device all the failed IOs are returned from the
host. A remove lun work item is issued per failed IO. If the outstanding
TURs have not been completed in a timely manner the scan_mutex is never
released or released too late. Consequently the many remove lun work
items are not completed as scsi_remove_device also tries to take
host->scan_mutex. This results in dragging the VM down and sometimes
completely.

This patch only allows one remove lun to be issued to a particular lun
while it is an instantiated member of the scsi stack.

Signed-off-by: Cathy Avery <cavery@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: fix memory leak on ring buffer busy

When storvsc is sending I/O to Hyper-v, it may allocate a bigger buffer
descriptor for large data payload that can't fit into a pre-allocated
buffer descriptor. This bigger buffer is freed on return path.

If I/O request to Hyper-v fails due to ring buffer busy, the storvsc
allocated buffer descriptor should also be freed.

[mkp: applied by hand]

Fixes: be0cf6ca301c ("scsi: storvsc: Set the tablesize based on the information given by the host")
Cc: <stable@vger.kernel.org>
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: use default I/O timeout handler for FC devices

FC disks issue I/O directly to the host storage port driver, this is
diffirent to VHD disks where I/O is virtualized and timeout is handled
by the host VSP (Virtualization Service Provider).

FC disks are usually setup in a multipath system, and they don't want to
reset timer on I/O timeout. Timeout is detected by multipath as a good
time to failover and recover.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: remove unnecessary channel inbound lock

In storvsc driver, inbound messages do not go through inbound lock. The
only effect of this lock was is to provide a barrier for connect and
remove logic.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: use in place iterator function

In 4.12-rc1, new functions were added to support iterating over elements
in the vmbus event ring. This patch uses them to simplify the ring
buffer handling in virtual SCSI driver as well.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Add support for FC rport.

Included in the current storvsc driver for Hyper-V is the ability to
access luns on an FC fabric via a virtualized fiber channel adapter
exposed by the Hyper-V host. The driver also attaches to the FC
transport to allow host and port names to be published under
/sys/class/fc_host/hostX. Current customer tools running on the VM
require that these names be available in the well known standard
location under fc_host/hostX.

This patch stubs in an rport per fc_host and sets its rport role as
FC_PORT_ROLE_FCP_DUMMY_INITIATOR to indicate to the fc_transport that it
is a pseudo rport in order to scan the scsi stack via echo "- - -" >
/sys/class/scsi_host/hostX/scan.

Signed-off-by: Cathy Avery <cavery@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: remove return at end of void function

storvsc_on_channel_callback is a void function and the return
statement at the end is not useful.

Found with checkpatch.

Signed-off-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Prefer kcalloc over kzalloc with multiply

Use kcalloc for allocating an array instead of kzalloc with multiply,
kcalloc is the preferred API.

Found with checkpatch.

Signed-off-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Workaround for virtual DVD SCSI version

Hyper-V host emulation of SCSI for virtual DVD device reports SCSI
version 0 (UNKNOWN) but is still capable of supporting REPORTLUN.

Without this patch, a GEN2 Linux guest on Hyper-V will not boot 4.11
successfully with virtual DVD ROM device. What happens is that the SCSI
scan process falls back to doing sequential probing by INQUIRY. But the
storvsc driver has a previous workaround that masks/blocks all errors
reports from INQUIRY (or MODE_SENSE) commands. This workaround causes
the scan to then populate a full set of bogus LUN's on the target and
then sends kernel spinning off into a death spiral doing block reads on
the non-existent LUNs.

By setting the correct blacklist flags, the target with the DVD device
is scanned with REPORTLUN and that works correctly.

Patch needs to go in current 4.11, it is safe but not necessary in older
kernels.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scripts/spelling.txt: add "intialization" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

intialization||initialization

The "inintialization" in drivers/acpi/spcr.c is a different pattern but
I fixed it as well in this commit.

Link: http://lkml.kernel.org/r/1481573103-11329-16-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scsi: remove eh_timed_out methods in the transport template

Instead define the timeout behavior purely based on the host_template
eh_timed_out method and wire up the existing transport implementations
in the host templates. This also clears up the confusion that the
transport template method overrides the host template one, so some
drivers have to re-override the transport template one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: remove bogus code to transfer struct scatterlist

Remove a piece of code in storvsc_queuecommand that tries to pass the
physical address of the kernel struct scatterlist pointer to the host.

Fortunately the code can't ever be reached anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: properly set residual data length on errors

On I/O errors, the Windows driver doesn't set data_transfer_length
on error conditions other than SRB_STATUS_DATA_OVERRUN.
In these cases we need to set data_transfer_length to 0,
indicating there is no data transferred. On SRB_STATUS_DATA_OVERRUN,
data_transfer_length is set by the Windows driver to the actual data transferred.

Reported-by: Shiva Krishna <Shiva.Krishna@nimblestorage.com>
Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: properly handle SRB_ERROR when sense message is present

When sense message is present on error, we should pass along to the upper
layer to decide how to deal with the error.
This patch fixes connectivity issues with Fiber Channel devices.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: use tagged SRB requests if supported by the device

Properly set SRB flags when hosting device supports tagged queuing.
This patch improves the performance on Fiber Channel disks.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Enable multi-queue support

Enable multi-q support. We will allocate the outgoing channel using
the following policy:

1. We will make every effort to pick a channel that is in the
same NUMA node that is initiating the I/O
2. The mapping between the guest CPU and the outgoing channel
is persistent.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Remove the restriction on max segment size

Remove the artificially imposed restriction on max segment size.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Enable tracking of queue depth

Enable tracking of queue depth.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Payload buffer incorrectly sized for 32 bit kernels.

On a 32 bit kernel sizeof(void *) is not 64 bits as hv_mpb_array
requires. Also the buffer needs to be cleared or the upper bytes will
contain junk.

Suggested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Cathy Avery <cavery@redhat.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Filter out storvsc messages CD-ROM medium not present

When a virtual scsi DVD device is present with no image file
attached the storvsc driver logs all resulting unnecessary sense errors
whenever IO is issued to the device.

[storvsc] Sense Key : Not Ready [current]
[storvsc] Add. Sense: Medium not present - tray closed

[mkp: Fixed whitespace]

Signed-off-by: Cathy Avery <cavery@redhat.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: fix SRB_STATUS_ABORTED handling

Commit 3209f9d780d1 ("scsi: storvsc: Fix a bug in the handling of SRB
status flags") filtered SRB_STATUS_AUTOSENSE_VALID out effectively making
the (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID) case a dead code. The
logic from this branch (e.g. storvsc_device_scan() call) is still required,
fix the check.

Cc: <stable@vger.kernel.org> #v4.4+
Fixes: 3209f9d780d1 ("scsi: storvsc: Fix a bug in the handling of SRB status flags")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: fix SRB_STATUS_ABORTED handling

Commit 3209f9d780d1 ("scsi: storvsc: Fix a bug in the handling of SRB
status flags") filtered SRB_STATUS_AUTOSENSE_VALID out effectively making
the (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID) case a dead code. The
logic from this branch (e.g. storvsc_device_scan() call) is still required,
fix the check.

Cc: <stable@vger.kernel.org> #v4.4+
Fixes: 3209f9d780d1 ("scsi: storvsc: Fix a bug in the handling of SRB status flags")
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Use the specified target ID in device lookup

The current code assumes that there is only one target in device lookup.
Fix this bug. This will alow us to correctly handle hot reomoval of
LUNs.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Alex Ng <alexng@microsoft.com>
Tested-by: Vivek Yadav <vyadav@microsoft.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Install the storvsc specific timeout handler for FC devices

The default timeout routine used for FC transport is not suitable for FC
devices managed by storvsc since FC devices managed by storvsc driver do
not have an rport associated with them. Use the time out handler used
for SCSI devices for FC devices as well.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Alex Ng <alexng@microsoft.com>
Tested-by: Vivek Yadav <vyadav@microsoft.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Fix typo in MODULE_PARM_DESC

The module_param is "storvsc_vcpus_per_sub_channel" so we need to use
that for MODULE_PARM_DESC() as well.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Tighten up the interrupt path

On the interrupt path, we repeatedly establish the pointer to the
storvsc_device. While the compiler does inline get_in_stor_device() (and
other static functions) in the call chain in the interrupt path, the
compiler is repeatedly inlining the call to get_in_stor_device() each
time it is invoked. The return value of get_in_stor_device() can be
cached in the interrupt path since there is higher level serialization
in place to ensure correct handling when the module unload races with
the processing of an incoming message from the host. Optimize this code
path by caching the pointer to storvsc_device and passing it as an
argument.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Refactor the code in storvsc_channel_init()

The function storvsc_channel_init() repeatedly interacts with the host
to extract various channel properties. Refactor this code to eliminate
code repetition.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Properly support Fibre Channel devices

For FC devices managed by this driver, atttach the appropriate transport
template. This will allow us to create the appropriate sysfs files for
these devices. With this we can publish the wwn for both the port and the node.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: Fix a bug in the layout of the hv_fc_wwn_packet

The hv_fc_wwn_packet is exchanged over vmbus. Make the definition in
Linux match the Windows definition.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Long Li <longli@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

storvsc: add logging for error/warning messages

Introduce a logging level for storvsc to log certain error/warning
messages. Those messages are helpful in some environments,
e.g. Microsoft Azure, for customer support and troubleshooting purposes.

Signed-off-by: Long Li <longli@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: storvsc: Fix a bug in the handling of SRB status flags

SRB status can have additional information. Mask these out before processing
SRB status.

This patch was sent as part of a collection of patches more than a year ago.
While the rest of the patches in the set were comitted, this patch was not.
I woulod like to thank Olaf for noticing that this patch was not committed
upstream.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: get rid of bounce buffer

Storvsc driver needs to ensure there are no 'holes' in the presented
sg list (all segments in the middle of the list need to be of PAGE_SIZE).
When a hole is detected storvsc driver creates a 'bounce sgl' without
holes and copies data over with copy_{to,from}_bounce_buffer() functions.
Setting virt_boundary_mask to PAGE_SIZE - 1 guarantees we'll never see
such holes so we can significantly simplify the driver. This is also
supposed to bring us some performance improvement for certain workloads
as we eliminate copying.

Reported-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Don't set the SRB_FLAGS_QUEUE_ACTION_ENABLE flag

Don't set the SRB_FLAGS_QUEUE_ACTION_ENABLE flag since we are not specifying
tags. Without this, the qlogic driver doesn't work properly with storvsc.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Set the error code correctly in failure conditions

In the function storvsc_channel_init(), error code was not getting
set correctly in some of the failure cases. Fix this issue.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Allow write_same when host is windows 10

Allow WRITE_SAME for Windows10 and above hosts.

Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: use storage protocol version to determine storage capabilities

Use storage protocol version instead of vmbus protocol
version when determining storage capabilities.

Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: use correct defaults for values determined by protocol negotiation

Use correct defaults for values determined by protocol negotiation,
instead of resetting them with every scsi controller.

Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Untangle the storage protocol negotiation from the vmbus protocol negotiation.

Currently we are making decisions based on vmbus protocol versions
that have been negotiated; use storage potocol versions instead.

[jejb: fold ARRAY_SIZE conversion suggested by Johannes Thumshirn
<jthumshirn@suse.de>
make vmstor_protocol static]
Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Use a single value to track protocol versions

Use a single value to track protocol versions to simplify
comparisons and to be consistent with vmbus version tracking.

Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Rather than look for sets of specific protocol versions, make decisions based on ranges.

Rather than look for sets of specific protocol versions,
make decisions based on ranges. This will be safer and require fewer changes
going forward as we add more storage protocol versions.

Tested-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: Keith Mange <keith.mange@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: use shost_for_each_device() instead of open coding

Comment in struct Scsi_Host says that drivers are not supposed to access
__devices directly. storvsc_host_scan() doesn't happen in irq context
so we can just use shost_for_each_device().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Long Li <longli@microsoft.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: be more picky about scmnd->sc_data_direction

Under the 'default' case in scmnd->sc_data_direction we have 3 options:
- DMA_NONE which we handle correctly.
- DMA_BIDIRECTIONAL which is never supposed to be set by SCSI stack.
- Garbage value.

Do WARN() and return -EINVAL in the last two cases. virtio_scsi does
BUG_ON() here but it looks like an overkill.

Reported-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: Set the SRB flags correctly when no data transfer is needed

Set the SRB flags correctly when there is no data transfer. Without this
change some IHV drivers will fail valid commands such as TEST_UNIT_READY.

Cc: <stable@vger.kernel.org>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Set the tablesize based on the information given by the host

Set the tablesize based on the information given by the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Tested-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Don't assume that the scatterlist is not chained

The current code assumes that the scatterlists presented are not chained.
Fix the code to not make this assumption.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Fix a bug in copy_from_bounce_buffer()

We may exit this function without properly freeing up the maapings
we may have acquired. Fix the bug.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Retrieve information about the capability of the target

The storage protocol informs the guest of the I/O capabilities of the storage
stack. Retrieve this information and use it in the guest.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Always send on the selected outgoing channel

The current code always sent packets without data on the primary channel.
Properly distribute sending of packets with no data amongst all available
channels. I would like to thank Long Li for noticing this problem.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Size the queue depth based on the ringbuffer size

Size the queue depth based on the ringbuffer size. Also accommodate for the
fact that we could have multiple channels (ringbuffers) per adaptor.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: storvsc: Increase the ring buffer size

Increase the default ring buffer size as this can significantly
improve performance especially on high latency storage back-ends.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

storvsc: force SPC-3 compliance on win8 and win8 r2 hosts

On win8 and win8 r2 hosts force SPC-3 compliance for MSFT virtual disks.
Ubuntu has been carrying a similar patch outside the tree for a while now.
Starting with win10, the host will support SPC-3 compliance. Based on all
the testing that has been done on win8 and win8 r2 hosts, we are comfortable
claiming SPC-3 compliance on these hosts as well. This will enable TRIM
support on these hosts.

Suggested by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

storvsc: fix a bug in storvsc limits

Commit 4cd83ecdac20d30725b4f96e5d7814a1e290bc7e changed the limits to
reflect the values on the host. It turns out that WS2008R2 cannot
correctly handle these new limits. Fix this bug by setting the limits
based on the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

storvsc: force discovery of LUNs that may have been removed.

The host asks the guest to scan when a LUN is removed or added.
The only way a guest can identify the removed LUN is when an I/O is
attempted on a removed LUN - the SRB status code indicates that the LUN
is invalid. We currently handle this SRB status and remove the device.

Rather than waiting for an I/O to remove the device, force the discovery of
LUNs that may have been removed prior to discovering LUNs that may have
been added.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

storvsc: in responce to a scan event, scan the host

The virtual HBA that storvsc implements can support multiple channels and
targets. So, scan the host when the host notifies that a scan is needed.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

storvsc: use cmd_size to allocate per-command data

STORVSC uses its own momory pool to manage device request data. However,
the SCSI layer already has a mechanisim for allocating additional memory
for each command issued to device driver. This patch removes the memory
pool in STORVSC and makes it use SCSI layer to allocate memory for device
request data.

Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

storvsc: ring buffer failures may result in I/O freeze

When ring buffer returns an error indicating retry, storvsc may not
return a proper error code to SCSI when bounce buffer is not used.
This has introduced I/O freeze on RAID running atop storvsc devices.
This patch fixes it by always returning a proper error code.

Signed-off-by: Long Li <longli@microsoft.com>
Reviewed-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
cc: stable@vger.kernel.org

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: use sdev as argument for sense code printing

We should be using the standard dev_printk() variants for
sense code printing.

[hch: remove __scsi_print_sense call in xen-scsiback, Acked by Juergen]
[hch: folded bracing fix from Dan Carpenter]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

storvsc: get rid of overly verbose warning messages

Get rid of the warning messages since they will clutter up various system logs
and are of questionable value to the end user. For debugging purposes, this
information can be gotten by setting the scsi log level appropriately.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Drivers: add blist flags

Add blist flags to permit the reading of the VPD pages even when
the target may claim SPC-2 compliance. MSFT targets currently
claim SPC-2 compliance while they implement post SPC-2 features.
With this patch we can correctly handle WRITE_SAME_16 issues.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers: scsi: storvsc: Correctly handle TEST_UNIT_READY failure

On some Windows hosts on FC SANs, TEST_UNIT_READY can return SRB_STATUS_ERROR.
Correctly handle this. Note that there is sufficient sense information to
support scsi error handling even in this case.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers: scsi: storvsc: Set srb_flags in all cases

Correctly set SRB flags for all valid I/O directions. Some IHV drivers on the
Windows host require this. The host validates the command and SRB flags
prior to passing the command down to native driver stack.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Drivers: scsi: storvsc: Implement a eh_timed_out handler

On Azure, we have seen instances of unbounded I/O latencies. To deal with
this issue, implement handler that can reset the timeout. Note that the
host gaurantees that it will respond to each command that has been issued.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
[hch: added a better comment explaining the issue]
Signed-off-by: Christoph Hellwig <hch@lst.de>

Drivers: scsi: storvsc: Fix a bug in handling VMBUS protocol version

Based on the negotiated VMBUS protocol version, we adjust the size of the storage
protocol messages. The two sizes we currently handle are pre-win8 and post-win8.
In WS2012 R2, we are negotiating higher VMBUS protocol version than the win8
version. Make adjustments to correctly handle this.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Drivers: scsi: storvsc: Filter commands based on the storage protocol version

Going forward it is possible that some of the commands that are not currently
implemented will be implemented on future Windows hosts. Even if they are not
implemented, we are told the host will corrrectly handle unsupported
commands (by returning appropriate return code and sense information).
Make command filtering depend on the host version.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Drivers: scsi: storvsc: Set cmd_per_lun to reflect value supported by the Host

Set cmd_per_lun to reflect value supported by the Host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Drivers: scsi: storvsc: Change the limits to reflect the values on the host

Hyper-V hosts can support multiple targets and multiple channels and larger number of
LUNs per target. Update the code to reflect this. With this patch we can correctly
enumerate all the paths in a multi-path storage environment.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

[SCSI] storvsc: NULL pointer dereference fix

If the initialization of storvsc fails, the storvsc_device_destroy()
causes NULL pointer dereference.

storvsc_bus_scan()
scsi_scan_target()
__scsi_scan_target()
scsi_probe_and_add_lun(hostdata=NULL)
scsi_alloc_sdev(hostdata=NULL)

sdev->hostdata = hostdata

now the host allocation fails

__scsi_remove_device(sdev)

calls sdev->host->hostt->slave_destroy() ==
storvsc_device_destroy(sdev)
access of sdev->hostdata->request_mempool

Signed-off-by: Ales Novak <alnovak@suse.cz>
Signed-off-by: Thomas Abraham <tabraham@suse.com>
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Disable WRITE SAME for RAID and virtual host adapter drivers

Some host adapters do not pass commands through to the target disk
directly. Instead they provide an emulated target which may or may not
accurately report its capabilities. In some cases the physical device
characteristics are reported even when the host adapter is processing
commands on the device's behalf. This can lead to adapter firmware hangs
or excessive I/O errors.

This patch disables WRITE SAME for devices connected to host adapters
that provide an emulated target. Driver writers can disable WRITE SAME
by setting the no_write_same flag in the host adapter template.

[jejb: fix up rejections due to eh_deadline patch]
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Drivers: hv: remove HV_DRV_VERSION

Remove HV_DRV_VERSION, it has no meaning for upstream drivers.

Initially it was supposed to show the "Linux Integration Services"
version, now it is not in sync anymore with the out-of-tree drivers
available from the MSFT website.

The only place where a version string is still required is the KVP
command "IntegrationServicesVersion" which is handled by
tools/hv/hv_kvp_daemon.c. To satisfy such KVP request from the host pass
the current string to the daemon during KVP userland registration.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[SCSI] storvsc: Increase the value of STORVSC_MAX_IO_REQUESTS

Increase the value of STORVSC_MAX_IO_REQUESTS to 200 requests. The current
ringbuffer size can support this higher value.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Support FC devices

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Implement multi-channel support

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Update the storage protocol to win8 level

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Increase the value of scsi timeout for storvsc devices

The standard scsi timeout is not appropriate in some of the environments where
Hyper-V is deployed. Set this timeout appropriately for all devices managed
by this driver.

On cloud environments where storage latencies may be unbounded, having the
scsi layer initiating recovery can be problematic since (a) the host is
already implementing a variety of recovery strategies and (b) implementing a
recovery strategy at the VM level may be more appropriate in cases where
storage latencies exceed a certain threshold.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Handle dynamic resizing of the device

Handle LUN size changes by re-scanning the device.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Restructure error handling code on command completion

In preparation for handling additional sense codes, restructure and cleanup
the error handling code in the command completion code path.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: avoid usage of WRITE_SAME

Set scsi_device->no_write_same because the host does not support it.
Also blacklist WRITE_SAME to avoid (and log) accident usage.

If the guest uses the ext4 filesystem, storvsc hangs while it prints
these messages in an endless loop:
...
[ 161.459523] hv_storvsc vmbus_0_1: cmd 0x41 scsi status 0x2 srb status 0x6
[ 161.462157] sd 2:0:0:0: [sda]
[ 161.463135] Sense Key : No Sense [current]
[ 161.464983] sd 2:0:0:0: [sda]
[ 161.465899] Add. Sense: No additional sense information
[ 161.468211] hv_storvsc vmbus_0_1: cmd 0x41 scsi status 0x2 srb status 0x6
[ 161.475766] sd 2:0:0:0: [sda]
[ 161.476728] Sense Key : No Sense [current]
[ 161.478284] sd 2:0:0:0: [sda]
[ 161.479441] Add. Sense: No additional sense information
...

This happens with a guest running on Windows Server 2012, but happens to
work while running on Windows Server 2008. WRITE_SAME isnt really
supported by both versions, so disable the command usage globally.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Initialize the sglist

Properly initialize scatterlist before using it.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Drivers: scsi: storvsc: Use the consolidated GUID definition

Use the consolidated GUID definitions in the Hyper-V storage driver.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[SCSI] storvsc: Account for in-transit packets in the RESET path

Properly account for I/O in transit before returning from the RESET call.
In the absense of this patch, we could have a situation where the host may
respond to a command that was issued prior to the issuance of the RESET
command at some arbitrary time after responding to the RESET command.
Currently, the host does not do anything with the RESET command.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] storvsc: Properly handle errors from the host

Hyper-V cannot process some commands like ATA_12 and ATA_16. It also returns a
very generic error when this happens (SRB_STATUS_ERROR). Most of the time we
treat SRB_STATUS_ERROR as DID_TARGET_FAILURE which causes error handler retry,
but in the case of pass through commands, they'll never succeed (and the error
handler will offline the device), so put a discriminating block in the command
completion routing and send the SRB_STATUS_ERROR upwards with DID_PASSTHROUGH
for commands we know should not be retried.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

Staging: hv: storvsc: Move the storage driver out of the staging area

The storage driver (storvsc_drv.c) handles all block storage devices
assigned to Linux guests hosted on Hyper-V. This driver has been in the
staging tree for a while and this patch moves it out of the staging area.

James was willing to apply this patch during the 3.3-rc phase and a decision
was taken to defer this to 3.4 since Greg had queued up a bunch of storvsc
patches for 3.4. Now that Greg has applied all of the pending storvsc patches,
I am sending this patch to move this driver out of staging. Based on James'
recommendation, this patch gets rid of the unneeded files in the staging/hv
directory.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>