virtio-pci: Initialize the supported admin commands

Initialize the supported admin commands upon activating the admin queue.

The supported commands are saved as part of the admin queue context.

Next patches in this series will expose APIs to use them.

Reviewed-by: Feng Liu <feliu@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20231219093247.170936-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/virtio: Clarify CONFIG_VIRTIO_MEM for unsupported architectures

Let's make it clearer that simply unlocking CONFIG_VIRTIO_MEM on an
architecture is most probably not sufficient to have it working as
expected.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20220610094737.65254-1-david@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: VIRTIO_HARDEN_NOTIFICATION is broken

This option doesn't really work and breaks too many drivers.
Not yet sure what's the right thing to do, for now
let's make sure randconfig isn't broken by this.

Fixes: c346dae4f3fb ("virtio: disable notification hardening by default")
Cc: "Jason Wang" <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

virtio: replace restricted mem access flag with callback

Instead of having a global flag to require restricted memory access
for all virtio devices, introduce a callback which can select that
requirement on a per-device basis.

For convenience add a common function returning always true, which can
be used for use cases like SEV.

Per default use a callback always returning false.

As the callback needs to be set in early init code already, add a
virtio anchor which is builtin in case virtio is enabled.

Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20220622063838.8854-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>

virtio: disable notification hardening by default

We try to harden virtio device notifications in 8b4ec69d7e09 ("virtio:
harden vring IRQ"). It works with the assumption that the driver or
core can properly call virtio_device_ready() at the right
place. Unfortunately, this seems to be not true and uncover various
bugs of the existing drivers, mainly the issue of using
virtio_device_ready() incorrectly.

So let's add a Kconfig option and disable it by default. It gives
us time to fix the drivers and then we can consider re-enabling it.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220622012940.21441-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>

virtio: replace arch_has_restricted_virtio_memory_access()

Instead of using arch_has_restricted_virtio_memory_access() together
with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those
with platform_has() and a new platform feature
PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov <bp@suse.de>

drivers/virtio: Enable virtio mem for ARM64

This enables virtio-mem device support by allowing to enable the
corresponding kernel config option (CONFIG_VIRTIO_MEM) on the
architecture.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20220119010551.181405-1-gshan@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>

virtio: drop default for virtio-mem

There's no special reason why virtio-mem needs a default that's
different from what kconfig provides, any more than e.g. virtio blk.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>

virtio-mem: disallow mapping virtio-mem memory via /dev/mem

We don't want user space to be able to map virtio-mem device memory
directly (e.g., via /dev/mem) in order to have guarantees that in a sane
setup we'll never accidentially access unplugged memory within the
device-managed region of a virtio-mem device, just as required by the
virtio-spec.

As soon as the virtio-mem driver is loaded, the device region is visible
in /proc/iomem via the parent device region. From that point on user
space is aware of the device region and we want to disallow mapping
anything inside that region (where we will dynamically (un)plug memory)
until the driver has been unloaded cleanly and e.g., another driver might
take over.

By creating our parent IORESOURCE_SYSTEM_RAM resource with
IORESOURCE_EXCLUSIVE, we will disallow any /dev/mem access to our device
region until the driver was unloaded cleanly and removed the parent
region. This will work even though only some memory blocks are actually
currently added to Linux and appear as busy in the resource tree.

So access to the region from user space is only possible
a) if we don't load the virtio-mem driver.
b) after unloading the virtio-mem driver cleanly.

Don't build virtio-mem if access to /dev/mem cannot be restricticted -- if
we have CONFIG_DEVMEM=y but CONFIG_STRICT_DEVMEM is not set.

Link: https://lkml.kernel.org/r/20210920142856.17758-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug: remove CONFIG_MEMORY_HOTPLUG_SPARSE

CONFIG_MEMORY_HOTPLUG depends on CONFIG_SPARSEMEM, so there is no need for
CONFIG_MEMORY_HOTPLUG_SPARSE anymore; adjust all instances to use
CONFIG_MEMORY_HOTPLUG and remove CONFIG_MEMORY_HOTPLUG_SPARSE.

Link: https://lkml.kernel.org/r/20210929143600.49379-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org> [kselftest]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

virtio-pci: introduce legacy device module

Split common codes from virtio-pci-legacy so vDPA driver can reuse it
later.

Signed-off-by: Wu Zongyong <wuzongyong@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/71605acde5e97fcb2760a6973e406279fb1bbd33.1635493219.git.wuzongyong@linux.alibaba.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio-pci: introduce modern device module

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210104065503.199631-17-jasowang@redhat.com

Including a bugfix:

virtio: don't prompt CONFIG_VIRTIO_PCI_MODERN

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: 86b87c9d858b6 ("virtio-pci: introduce modern device module")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210223061905.422659-2-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: let arch advertise guest's memory access restrictions

An architecture may restrict host access to guest memory,
e.g. IBM s390 Secure Execution or AMD SEV.

Provide a new Kconfig entry the architecture can select,
CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, when it provides
the arch_has_restricted_virtio_memory_access callback to advertise
to VIRTIO common code when the architecture restricts memory access
from the host.

The common code can then fail the probe for any device where
VIRTIO_F_ACCESS_PLATFORM is required, but not set.

Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Link: https://lore.kernel.org/r/1599728030-17085-2-git-send-email-pmorel@linux.ibm.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>

virtio: fix build for configs without dma-bufs

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David Stevens <stevensd@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200819031011.310180-1-stevensd@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

virtio-mem: Fix build error due to improper use 'select'

As noted in:
https://www.kernel.org/doc/Documentation/kbuild/kconfig-language.txt
"select should be used with care. select will force a symbol to a
value without visiting the dependencies."
Config VIRTIO_MEM should not select CONTIG_ALLOC directly.
Otherwise it will cause an error:
https://bugzilla.kernel.org/show_bug.cgi?id=208245

Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Link: https://lore.kernel.org/r/20200619080333.194753-1-chenweilong@huawei.com
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>

treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

a) 4 spaces + '---help---'
b) 7 spaces + '---help---'
c) 8 spaces + '---help---'
d) 1 space + 1 tab + '---help---'
e) 1 tab + '---help---' (correct indentation)
f) 1 tab + 1 space + '---help---'
g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

$ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

virtio-mem: Paravirtualized memory hotunplug part 2

We also want to unplug online memory (contained in online memory blocks
and, therefore, managed by the buddy), and eventually replug it later.

When requested to unplug memory, we use alloc_contig_range() to allocate
subblocks in online memory blocks (so we are the owner) and send them to
our hypervisor. When requested to plug memory, we can replug such memory
using free_contig_range() after asking our hypervisor.

We also want to mark all allocated pages PG_offline, so nobody will
touch them. To differentiate pages that were never onlined when
onlining the memory block from pages allocated via alloc_contig_range(), we
use PageDirty(). Based on this flag, virtio_mem_fake_online() can either
online the pages for the first time or use free_contig_range().

It is worth noting that there are no guarantees on how much memory can
actually get unplugged again. All device memory might completely be
fragmented with unmovable data, such that no subblock can get unplugged.

We are not touching the ZONE_MOVABLE. If memory is onlined to the
ZONE_MOVABLE, it can only get unplugged after that memory was offlined
manually by user space. In normal operation, virtio-mem memory is
suggested to be onlined to ZONE_NORMAL. In the future, we will try to
make unplug more likely to succeed.

Add a module parameter to control if online memory shall be touched.

As we want to access alloc_contig_range()/free_contig_range() from
kernel module context, export the symbols.

Note: Whenever virtio-mem uses alloc_contig_range(), all affected pages
are on the same node, in the same zone, and contain no holes.

Acked-by: Michal Hocko <mhocko@suse.com> # to export contig range allocator API
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-6-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio-mem: Paravirtualized memory hotplug

Each virtio-mem device owns exactly one memory region. It is responsible
for adding/removing memory from that memory region on request.

When the device driver starts up, the requested amount of memory is
queried and then plugged to Linux. On request, further memory can be
plugged or unplugged. This patch only implements the plugging part.

On x86-64, memory can currently be plugged in 4MB ("subblock") granularity.
When required, a new memory block will be added (e.g., usually 128MB on
x86-64) in order to plug more subblocks. Only x86-64 was tested for now.

The online_page callback is used to keep unplugged subblocks offline
when onlining memory - similar to the Hyper-V balloon driver. Unplugged
pages are marked PG_offline, to tell dump tools (e.g., makedumpfile) to
skip them.

User space is usually responsible for onlining the added memory. The
memory hotplug notifier is used to synchronize virtio-mem activity
against memory onlining/offlining.

Each virtio-mem device can belong to a NUMA node, which allows us to
easily add/remove small chunks of memory to/from a specific NUMA node by
using multiple virtio-mem devices. Something that works even when the
guest has no idea about the NUMA topology.

One way to view virtio-mem is as a "resizable DIMM" or a DIMM with many
"sub-DIMMS".

This patch directly introduces the basic infrastructure to implement memory
unplug. Especially the memory block states and subblock bitmaps will be
heavily used there.

Notes:
- In case memory is to be onlined by user space, we limit the amount of
offline memory blocks, to not run out of memory. This is esp. an
issue if memory is added faster than it is getting onlined.
- Suspend/Hibernate is not supported due to the way virtio-mem devices
behave. Limited support might be possible in the future.
- Reloading the device driver is not supported.

Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-acpi@vger.kernel.org
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20200507140139.17083-2-david@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vdpa: make vhost, virtio depend on menu

If user did not configure any vdpa drivers, neither vhost
nor virtio vdpa are going to be useful. So there's no point
in prompting for these and selecting vdpa core automatically.
Simplify configuration by making virtio and vhost vdpa
drivers depend on vdpa menu entry. Once done, we no longer
need a separate menu entry, so also get rid of this.
While at it, fix up the IFC entry: VDPA->vDPA for consistency
with other places.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

virtio-balloon: add support for providing free page reports to host

Add support for the page reporting feature provided by virtio-balloon.
Reporting differs from the regular balloon functionality in that is is
much less durable than a standard memory balloon. Instead of creating a
list of pages that cannot be accessed the pages are only inaccessible
while they are being indicated to the virtio interface. Once the
interface has acknowledged them they are placed back into their respective
free lists and are once again accessible by the guest system.

Unlike a standard balloon we don't inflate and deflate the pages. Instead
we perform the reporting, and once the reporting is completed it is
assumed that the page has been dropped from the guest and will be faulted
back in the next time the page is accessed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nitesh Narayan Lal <nitesh@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pankaj Gupta <pagupta@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Wang <wei.w.wang@intel.com>
Cc: Yang Zhang <yang.zhang.wz@gmail.com>
Cc: wei qi <weiqi4@huawei.com>
Link: http://lkml.kernel.org/r/20200211224657.29318.68624.stgit@localhost.localdomain
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vdpa: move to drivers/vdpa

We have both vhost and virtio drivers that depend on vdpa.
It's easier to locate it at a top level directory otherwise
we run into issues e.g. if vhost is built-in but virtio
is modular. Let's just move it up a level.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio: introduce a vDPA based transport

This patch introduces a vDPA transport for virtio. This is used to
use kernel virtio driver to drive the vDPA device that is capable
of populating virtqueue directly.

A new virtio-vdpa driver will be registered to the vDPA bus, when a
new virtio-vdpa device is probed, it will register the device with
vdpa based config ops. This means it is a software transport between
vDPA driver and vDPA device. The transport was implemented through
bus_ops of vDPA parent.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200326140125.19794-7-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

vDPA: introduce vDPA bus

vDPA device is a device that uses a datapath which complies with the
virtio specifications with vendor specific control path. vDPA devices
can be both physically located on the hardware or emulated by
software. vDPA hardware devices are usually implemented through PCIE
with the following types:

- PF (Physical Function) - A single Physical Function
- VF (Virtual Function) - Device that supports single root I/O
virtualization (SR-IOV). Its Virtual Function (VF) represents a
virtualized instance of the device that can be assigned to different
partitions
- ADI (Assignable Device Interface) and its equivalents - With
technologies such as Intel Scalable IOV, a virtual device (VDEV)
composed by host OS utilizing one or more ADIs. Or its equivalent
like SF (Sub function) from Mellanox.

>From a driver's perspective, depends on how and where the DMA
translation is done, vDPA devices are split into two types:

- Platform specific DMA translation - From the driver's perspective,
the device can be used on a platform where device access to data in
memory is limited and/or translated. An example is a PCIE vDPA whose
DMA request was tagged via a bus (e.g PCIE) specific way. DMA
translation and protection are done at PCIE bus IOMMU level.
- Device specific DMA translation - The device implements DMA
isolation and protection through its own logic. An example is a vDPA
device which uses on-chip IOMMU.

To hide the differences and complexity of the above types for a vDPA
device/IOMMU options and in order to present a generic virtio device
to the upper layer, a device agnostic framework is required.

This patch introduces a software vDPA bus which abstracts the
common attributes of vDPA device, vDPA bus driver and the
communication method (vdpa_config_ops) between the vDPA device
abstraction and the vDPA bus driver. This allows multiple types of
drivers to be used for vDPA device like the virtio_vdpa and vhost_vdpa
driver to operate on the bus and allow vDPA device could be used by
either kernel virtio driver or userspace vhost drivers as:

virtio drivers vhost drivers
| |
[virtio bus] [vhost uAPI]
| |
virtio device vhost device
virtio_vdpa drv vhost_vdpa drv
\ /
[vDPA bus]
|
vDPA device
hardware drv
|
[hardware bus]
|
vDPA hardware

With the abstraction of vDPA bus and vDPA bus operations, the
difference and complexity of the under layer hardware is hidden from
upper layer. The vDPA bus drivers on top can use a unified
vdpa_config_ops to control different types of vDPA device.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20200326140125.19794-6-jasowang@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

virtio-pmem: Add virtio pmem driver

This patch adds virtio-pmem driver for KVM guest.

Guest reads the persistent memory range information from
Qemu over VIRTIO and registers it on nvdimm_bus. It also
creates a nd_region object with the persistent memory
range information so that existing 'nvdimm/pmem' driver
can reserve this into system memory map. This way
'virtio-pmem' driver uses existing functionality of pmem
driver to register persistent memory compatible for DAX
capable filesystems.

This also provides function to perform guest flush over
VIRTIO from 'pmem' driver when userspace performs flush
on DAX memory range.

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jakub Staron <jstaron@google.com>
Tested-by: Jakub Staron <jstaron@google.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

virtio: Fix indentation of VIRTIO_MMIO

VIRTIO_MMIO config option block starts with a space, fix that.

Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virtio: make VIRTIO a menuconfig to ease disabling it all

No need to get into the submenu to disable all VIRTIO-related
config entries.

This makes it easier to disable all VIRTIO config options
without entering the submenu. It will also enable one
to see that en/dis-abled state from the outside menu.

This is only intended to change menuconfig UI, not change
the config dependencies.

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

x86/lguest: Remove lguest support

Lguest seems to be rather unused these days. It has seen only patches
ensuring it still builds the last two years and its official state is
"Odd Fixes".

Remove it in order to be able to clean up the paravirt code.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: boris.ostrovsky@oracle.com
Cc: lguest@lists.ozlabs.org
Cc: rusty@rustcorp.com.au
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20170816173157.8633-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

docs: fix locations of several documents that got moved

The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

virtio_ring: Support DMA APIs

virtio_ring currently sends the device (usually a hypervisor)
physical addresses of its I/O buffers. This is okay when DMA
addresses and physical addresses are the same thing, but this isn't
always the case. For example, this never works on Xen guests, and
it is likely to fail if a physical "virtio" device ever ends up
behind an IOMMU or swiotlb.

The immediate use case for me is to enable virtio on Xen guests.
For that to work, we need vring to support DMA address translation
as well as a corresponding change to virtio_pci or to another
driver.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Add virtio-input driver.

virtio-input is basically evdev-events-over-virtio, so this driver isn't
much more than reading configuration from config space and forwarding
incoming events to the linux input layer.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio_pci: add an option to disable legacy driver

Useful for testing device virtio 1 compatibility.
Based on patch by Rusty - couldn't resist putting
that flying car joke in there!

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio_pci: drop Kconfig warnings

The ABI *is* stable, and has been for a while now.
Drop Kconfig warning saying that it's not guaranteed
to work.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio_pci: Kconfig grammar fix

This drivers -> this driver.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

mm/balloon_compaction: add vmstat counters and kpageflags bit

Always mark pages with PageBalloon even if balloon compaction is disabled
and expose this mark in /proc/kpageflags as KPF_BALLOON.

Also this patch adds three counters into /proc/vmstat: "balloon_inflate",
"balloon_deflate" and "balloon_migrate". They accumulate balloon
activity. Current size of balloon is (balloon_inflate - balloon_deflate)
pages.

All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON.
It should be selected by ballooning driver which wants use this feature.
Currently virtio-balloon is the only user.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/virtio: remove depends on CONFIG_EXPERIMENTAL

The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

CC: Rusty Russell <rusty@rustcorp.com.au>
CC: "Michael S. Tsirkin" <mst@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: remove CONFIG_VIRTIO_RING

Everyone who selects VIRTIO is also made to select VIRTIO_RING; just make
them synonymous, since we removed the indirection layer some time ago.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: add help to CONFIG_VIRTIO option.

Trying to enable a virtio driver (eg CONFIG_VIRTIO_BLK) is painful
because it depends on CONFIG_VIRTIO. CONFIG_VIRTIO doesn't tell you
how to turn it on (it's selected from anything which provides a virtio
bus).

This patch at least adds some documentation, visible in menuconfig, as
a hint.

Reported-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio_balloon: not EXPERIMENTAL any more.

It is not experimental in any vaguely-sane sense.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio-balloon: dependency fix

Devices should depend on virtio, not select it. It's supposed to be
selected by the particular driver, e.g. VIRTIO_PCI.
Make balloon depend on VIRTIO and EXPERIMENTAL
(to match description).

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio-mmio: Devices parameter parsing

This patch adds an option to instantiate guest virtio-mmio devices
basing on a kernel command line (or module) parameter, for example:

virtio_mmio.devices=0x100@0x100b0000:48

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: add HAS_IOMEM dependency to MMIO platform bus driver

Fix this compile error on s390:

CC [M] drivers/virtio/virtio_mmio.o
drivers/virtio/virtio_mmio.c: In function 'vm_get_features':
drivers/virtio/virtio_mmio.c:107:2: error: implicit declaration of function 'writel'

Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: Add platform bus driver for memory mapped virtio device

This patch, based on virtio PCI driver, adds support for memory
mapped (platform) virtio device. This should allow environments
like qemu to use virtio-based block & network devices even on
platforms without PCI support.

One can define and register a platform device which resources
will describe memory mapped control registers and "mailbox"
interrupt. Such device can be also instantiated using the Device
Tree node with compatible property equal "virtio,mmio".

Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Michael S.Tsirkin <mst@redhat.com>
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: expose for non-virtualization users too

virtio has been so far used only in the context of virtualization,
and the virtio Kconfig was sourced directly by the relevant arch
Kconfigs when VIRTUALIZATION was selected.

Now that we start using virtio for inter-processor communications,
we need to source the virtio Kconfig outside of the virtualization
scope too.

Moreover, some architectures might use virtio for both virtualization
and inter-processor communications, so directly sourcing virtio
might yield unexpected results due to conflicting selections.

The simple solution offered by this patch is to always source virtio's
Kconfig in drivers/Kconfig, and remove it from the appropriate arch
Kconfigs. Additionally, a virtio menu entry has been added so virtio
drivers don't show up in the general drivers menu.

This way anyone can use virtio, though it's arguably less accessible
(and neat!) for virtualization users now.

Note: some architectures (mips and sh) seem to have a VIRTUALIZATION
menu merely for sourcing virtio's Kconfig, so that menu is removed too.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: balloon driver

After discussions with Anthony Liguori, it seems that the virtio
balloon can be made even simpler. Here's my attempt.

The device configuration tells the driver how much memory it should
take from the guest (ie. balloon size). The guest feeds the page
numbers it has taken via one virtqueue.

A second virtqueue feeds the page numbers the driver wants back: if
the device has the VIRTIO_BALLOON_F_MUST_TELL_HOST bit, then this
queue is compulsory, otherwise it's advisory (and the guest can simply
fault the pages back in).

This driver can be enhanced later to deflate the balloon via a
shrinker, oom callback or we could even go for a complete set of
in-guest regulators.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: PCI device

This is a PCI device that implements a transport for virtio. It allows virtio
devices to be used by QEMU based VMMs like KVM or Xen.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

virtio: Allow virtio to be modular and used by modules

This is needed for the virtio PCI device to be compiled as a module.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Virtio helper routines for a descriptor ringbuffer implementation

These helper routines supply most of the virtqueue_ops for hypervisors
which want to use a ring for virtio. Unlike the previous lguest
implementation:

1) The rings are variable sized (2^n-1 elements).
2) They have an unfortunate limit of 65535 bytes per sg element.
3) The page numbers are always 64 bit (PAE anyone?)
4) They no longer place used[] on a separate page, just a separate
cacheline.
5) We do a modulo on a variable. We could be tricky if we cared.
6) Interrupts and notifies are suppressed using flags within the rings.

Users need only get the ring pages and provide a notify hook (KVM
wants the guest to allocate the rings, lguest does it sanely).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dor Laor <dor.laor@qumranet.com>

Virtio interface

This attempts to implement a "virtual I/O" layer which should allow
common drivers to be efficiently used across most virtual I/O
mechanisms. It will no-doubt need further enhancement.

The virtio drivers add buffers to virtio queues; as the buffers are consumed
the driver "interrupt" callbacks are invoked.

There is also a generic implementation of config space which drivers can query
to get setup information from the host.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dor Laor <dor.laor@qumranet.com>
Cc: Arnd Bergmann <arnd@arndb.de>