iommu: constify of_phandle_args in xlate

The xlate callbacks are supposed to translate of_phandle_args to proper
provider without modifying the of_phandle_args. Make the argument
pointer to const for code safety and readability.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240216144027.185959-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Clean up open-coded ownership checks

Some drivers already implement their own defence against the possibility
of being given someone else's device. Since this is now taken care of by
the core code (and via a slightly different path from the original
fwspec-based idea), let's clean them up.

Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/58a9879ce3f03562bb061e6714fe6efb554c3907.1700589539.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Add ops->flush_iotlb_all and enable deferred flush

Add ops->flush_iotlb_all operation to enable virtio-iommu for the
dma-iommu deferred flush scheme. This results in a significant increase
in performance in exchange for a window in which devices can still
access previously IOMMU mapped memory when running with
CONFIG_IOMMU_DEFAULT_DMA_LAZY. The previous strict behavior can be
achieved with iommu.strict=1 on the kernel command line or
CONFIG_IOMMU_DEFAULT_DMA_STRICT.

Link: https://lore.kernel.org/lkml/20230802123612.GA6142@myrica/
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20231120-viommu-sync-map-v3-2-50a57ecf78b5@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Make use of ops->iotlb_sync_map

Pull out the sync operation from viommu_map_pages() by implementing
ops->iotlb_sync_map. This allows the common IOMMU code to map multiple
elements of an sg with a single sync (see iommu_map_sg()).

Link: https://lore.kernel.org/lkml/20230726111433.1105665-1-schnelle@linux.ibm.com/
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20231120-viommu-sync-map-v3-1-50a57ecf78b5@linux.ibm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Add __counted_by for struct viommu_request and use struct_size()

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

While there, use struct_size() helper, instead of the open-coded
version, to calculate the size for the allocation of the whole
flexible structure, including of course, the flexible-array member.

This code was found with the help of Coccinelle, and audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/ZSRFW0yDlDo8+at3@work
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20230714174640.4058404-1-robh@kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Return size mapped for a detached domain

When map() is called on a detached domain, the domain does not exist in
the device so we do not send a MAP request, but we do update the
internal mapping tree, to be replayed on the next attach. Since this
constitutes a successful iommu_map() call, return *mapped in this case
too.

Fixes: 7e62edd7a33a ("iommu/virtio: Add map/unmap_pages() callbacks implementation")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230515113946.1017624-3-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Detach domain on endpoint release

When an endpoint is released, for example a PCIe VF being destroyed or a
function hot-unplugged, it should be detached from its domain. Send a
DETACH request.

Fixes: edcd69ab9a32 ("iommu: Add virtio-iommu driver")
Reported-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Link: https://lore.kernel.org/all/15bf1b00-3aa0-973a-3a86-3fa5c4d41d2c@daynix.com/
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Tested-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Link: https://lore.kernel.org/r/20230515113946.1017624-2-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Propagate return value in ->attach_dev callback functions

The mtk_iommu and virtio drivers have places in the ->attach_dev callback
functions that return hardcode errnos instead of the returned values, but
callers of these ->attach_dv callback functions may care. Propagate them
directly without the extra conversions.

Link: https://lore.kernel.org/r/ca8c5a447b87002334f83325f28823008b4ce420.1666042873.git.nicolinc@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommu: Use EINVAL for incompatible device/domain in ->attach_dev

Following the new rules in include/linux/iommu.h kdocs, update all drivers
->attach_dev callback functions to return EINVAL in the failure paths that
are related to domain incompatibility.

Also, drop adjacent error prints to prevent a kernel log spam.

Link: https://lore.kernel.org/r/f52a07f7320da94afe575c9631340d0019a203a7.1666042873.git.nicolinc@nvidia.com
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommu: Regulate EINVAL in ->attach_dev callback functions

Following the new rules in include/linux/iommu.h kdocs, EINVAL now can be
used to indicate that domain and device are incompatible by a caller that
treats it as a soft failure and tries attaching to another domain.

On the other hand, there are ->attach_dev callback functions returning it
for obvious device-specific errors. They will result in some inefficiency
in the caller handling routine.

Update these places to corresponding errnos following the new rules.

Link: https://lore.kernel.org/r/5924c03bea637f05feb2a20d624bae086b555ec5.1666042872.git.nicolinc@nvidia.com
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommu: Add gfp parameter to iommu_alloc_resv_region

Add gfp parameter to iommu_alloc_resv_region() for the callers to specify
the memory allocation behavior. Thus iommu_alloc_resv_region() could also
be available in critical contexts.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20220927053109.4053662-2-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Fix compile error with viommu_capable()

A recent fix introduced viommu_capable() but other changes
from Robin change the function signature of the call-back it
is used for.

When both changes are merged a compile error will happen
because the function pointer types mismatch. Fix that by
updating the viommu_capable() signature after the merge.

Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20220907151154.21911-1-joro@8bytes.org

iommu/dma: Make header private

Now that dma-iommu.h only contains internal interfaces, make it
private to the IOMMU subsytem.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/b237e06c56a101f77af142a54b629b27aa179d22.1660668998.git.robin.murphy@arm.com
[ joro : re-add stub for iommu_dma_get_resv_regions ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Clean up bus_set_iommu()

Stop calling bus_set_iommu() since it's now unnecessary, and simplify
the probe failure path accordingly.

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/0ff6f9166081724510e6772e43d45b317cab8c58.1660572783.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Do not dereference fwnode in struct device

In order to make the underneath API easier to change in the future,
prevent users from dereferencing fwnode from struct device.
Instead, use the specific device_match_fwnode() API for that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20220801165142.20898-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Fix interaction with VFIO

Commit e8ae0e140c05 ("vfio: Require that devices support DMA cache
coherence") requires IOMMU drivers to advertise
IOMMU_CAP_CACHE_COHERENCY, in order to be used by VFIO. Since VFIO does
not provide to userspace the ability to maintain coherency through cache
invalidations, it requires hardware coherency. Advertise the capability
in order to restore VFIO support.

The meaning of IOMMU_CAP_CACHE_COHERENCY also changed from "IOMMU can
enforce cache coherent DMA transactions" to "IOMMU_CACHE is supported".
While virtio-iommu cannot enforce coherency (of PCIe no-snoop
transactions), it does support IOMMU_CACHE.

We can distinguish different cases of non-coherent DMA:

(1) When accesses from a hardware endpoint are not coherent. The host
would describe such a device using firmware methods ('dma-coherent'
in device-tree, '_CCA' in ACPI), since they are also needed without
a vIOMMU. In this case mappings are created without IOMMU_CACHE.
virtio-iommu doesn't need any additional support. It sends the same
requests as for coherent devices.

(2) When the physical IOMMU supports non-cacheable mappings. Supporting
those would require a new feature in virtio-iommu, new PROBE request
property and MAP flags. Device drivers would use a new API to
discover this since it depends on the architecture and the physical
IOMMU.

(3) When the hardware supports PCIe no-snoop. It is possible for
assigned PCIe devices to issue no-snoop transactions, and the
virtio-iommu specification is lacking any mention of this.

Arm platforms don't necessarily support no-snoop, and those that do
cannot enforce coherency of no-snoop transactions. Device drivers
must be careful about assuming that no-snoop transactions won't end
up cached; see commit e02f5c1bb228 ("drm: disable uncached DMA
optimization for ARM and arm64"). On x86 platforms, the host may or
may not enforce coherency of no-snoop transactions with the physical
IOMMU. But according to the above commit, on x86 a driver which
assumes that no-snoop DMA is compatible with uncached CPU mappings
will also work if the host enforces coherency.

Although these issues are not specific to virtio-iommu, it could be
used to facilitate discovery and configuration of no-snoop. This
would require a new feature bit, PROBE property and ATTACH/MAP
flags.

Cc: stable@vger.kernel.org
Fixes: e8ae0e140c05 ("vfio: Require that devices support DMA cache coherence")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20220825154622.86759-1-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: remove the put_resv_regions method

All drivers that implement get_resv_regions just use
generic_put_resv_regions to implement the put side. Remove the
indirections and document the allocations constraints.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220708080616.238833-4-hch@lst.de
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Add map/unmap_pages() callbacks implementation

Map/unmap_pags() allows map and unmap multiple pages of the same size
in one call, which can improve performance by reducing the numbers of
vmexits. With map/unmap_pages() implemented, the prior map/unmap()
callbacks are deprecated.

Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20220605161152.3171-1-tina.zhang@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Clean up release_device checks

Since .release_device is now called through per-device ops, any call
which gets as far as a driver definitely *is* for that driver, for a
device which has successfully passed .probe_device, so all the checks to
that effect are now redundant and can be removed. In the same vein we
can also skip freeing fwspecs which are now managed by core code.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/02671dbfad7a3343fc25a44222350efcb455fe3c.1655822151.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Split struct iommu_ops

Move the domain specific operations out of struct iommu_ops into a new
structure that only has domain specific operations. This solves the
problem of needing to know if the method vector for a given operation
needs to be retrieved from the device or the domain. Logically the domain
ops are the ones that make sense for external subsystems and endpoint
drivers to use, while device ops, with the sole exception of domain_alloc,
are IOMMU API internals.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220216025249.3459465-10-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

virtio: wrap config->reset calls

This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

iommu/virtio: Fix typo in a comment

The double `as' in a comment is repeated, thus it should be removed.

Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20211216083302.18049-1-wangxiang@cdjrlc.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Support identity-mapped domains

Support identity domains for devices that do not offer the
VIRTIO_IOMMU_F_BYPASS_CONFIG feature, by creating 1:1 mappings between
the virtual and physical address space. Identity domains created this
way still perform noticeably better than DMA domains, because they don't
have the overhead of setting up and tearing down mappings at runtime.
The performance difference between this and bypass is minimal in
comparison.

It does not matter that the physical addresses in the identity mappings
do not all correspond to memory. By enabling passthrough we are trusting
the device driver and the device itself to only perform DMA to suitable
locations. In some cases it may even be desirable to perform DMA to MMIO
regions.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20211201173323.1045819-6-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Pass end address to viommu_add_mapping()

To support identity mappings, the virtio-iommu driver must be able to
represent full 64-bit ranges internally. Pass (start, end) instead of
(start, size) to viommu_add/del_mapping().

Clean comments. The one about the returned size was never true: when
sweeping the whole address space the returned size will most certainly
be smaller than 2^64.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20211201173323.1045819-5-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Sort reserved regions

To ease identity mapping support, keep the list of reserved regions
sorted.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20211201173323.1045819-4-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Support bypass domains

The VIRTIO_IOMMU_F_BYPASS_CONFIG feature adds a new flag to the ATTACH
request, that creates a bypass domain. Use it to enable identity
domains.

When VIRTIO_IOMMU_F_BYPASS_CONFIG is not supported by the device, we
currently fail attaching to an identity domain. Future patches will
instead create identity mappings in this case.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20211201173323.1045819-3-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Drop IOVA cookie management

The core code bakes its own cookies now.

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/f05cd2d0a0f414de3180e2536c7656faf1e52418.1628682049.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Enable x86 support

With the VIOT support in place, x86 platforms can now use the
virtio-iommu.

Because the other x86 IOMMU drivers aren't yet ready to use the
acpi_dma_setup() path, x86 doesn't implement arch_setup_dma_ops() at the
moment. Similarly to Vt-d and AMD IOMMU, clear the DMA ops and call
iommu_setup_dma_ops() from probe_finalize().

Acked-by: Joerg Roedel <jroedel@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210618152059.1194210-6-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Drop unnecessary of_iommu.h includes

The only place of_iommu.h is needed is in drivers/of/device.c. Remove it
from everywhere else.

Cc: Will Deacon <will@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Yong Wu <yong.wu@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: iommu@lists.linux-foundation.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20210527193710.1281746-2-robh@kernel.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Add missing MODULE_DEVICE_TABLE

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Fixes: fa4afd78ea12 ("iommu/virtio: Build virtio-iommu as module")
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20210508031451.53493-1-cuibixuan@huawei.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Streamline registration interface

Rather than have separate opaque setter functions that are easy to
overlook and lead to repetitive boilerplate in drivers, let's pass the
relevant initialisation parameters directly to iommu_device_register().

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/ab001b87c533b6f4db71eb90db6f888953986c36.1617285386.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Statically set module owner

It happens that the 3 drivers which first supported being modular are
also ones which play games with their pgsize_bitmap, so have non-const
iommu_ops where dynamically setting the owner manages to work out OK.
However, it's less than ideal to force that upon all drivers which want
to be modular - like the new sprd-iommu driver which now has a potential
bug in that regard - so let's just statically set the module owner and
let ops remain const wherever possible.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/31423b99ff609c3d4b291c701a7a7a810d9ce8dc.1617285386.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

virtio-iommu: convert to LE accessors

Virtio iommu is modern-only. Use LE accessors for config space.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

iommu/virtio: Reverse arguments to list_add

Elsewhere in the file, there is a list_for_each_entry with
&vdev->resv_regions as the second argument, suggesting that
&vdev->resv_regions is the list head. So exchange the
arguments on the list_add call to put the list head in the
second argument.

Fixes: 2a5a31487445 ("iommu/virtio: Add probe request")
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/1588704467-13431-1-git-send-email-Julia.Lawall@inria.fr
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Convert to probe/release_device() call-backs

Convert the VirtIO IOMMU driver to use the probe_device() and
release_device() call-backs of iommu_ops, so that the iommu core code
does the group and sysfs setup.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20200429133712.31431-21-joro@8bytes.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Use accessor functions for iommu private data

Make use of dev_iommu_priv_set/get() functions.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20200326150841.10083-16-joro@8bytes.org

iommu/virtio: Reject IOMMU page granule larger than PAGE_SIZE

We don't currently support IOMMUs with a page granule larger than the
system page size. The IOVA allocator has a BUG_ON() in this case, and
VFIO has a WARN_ON().

Removing these obstacles ranges doesn't seem possible without major
changes to the DMA API and VFIO. Some callers of iommu_map(), for
example, want to map multiple page-aligned regions adjacent to each
others for scatter-gather purposes. Even in simple DMA API uses, a call
to dma_map_page() would let the endpoint access neighbouring memory. And
VFIO users cannot ensure that their virtual address buffer is physically
contiguous at the IOMMU granule.

Rather than triggering the IOVA BUG_ON() on mismatched page sizes, abort
the vdomain finalise() with an error message. We could simply abort the
viommu probe(), but an upcoming extension to virtio-iommu will allow
setting different page masks for each endpoint.

Reported-by: Bharat Bhushan <bbhushan2@marvell.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Bharat Bhushan <bbhushan2@marvell.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200326093558.2641019-4-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Fix freeing of incomplete domains

Calling viommu_domain_free() on a domain that hasn't been finalised (not
attached to any device, for example) can currently cause an Oops,
because we attempt to call ida_free() on ID 0, which may either be
unallocated or used by another domain.

Only initialise the vdomain->viommu pointer, which denotes a finalised
domain, at the end of a successful viommu_domain_finalise().

Fixes: edcd69ab9a32 ("iommu: Add virtio-iommu driver")
Reported-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20200326093558.2641019-3-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Build virtio-iommu as module

Now that the infrastructure changes are in place, enable virtio-iommu to
be built as a module. Remove the redundant pci_request_acs() call, since
it's not exported but is already invoked during DMA setup.

Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: virtio: Use generic_iommu_put_resv_regions()

Use the new standard function instead of open-coding it.

Cc: Jean-Philippe Brucker <jean-philippe@linaro.org>
Cc: virtualization@lists.linux-foundation.org
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Remove unused variable

Remove the variable of return. Issue found by
coccicheck(scripts/coccinelle/misc/returnvar.cocci)

Signed-off-by: Cristiane Naves <cristianenavescardoso09@gmail.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Add gfp parameter to iommu_ops::map

Add a gfp_t parameter to the iommu_ops::map function.
Remove the needless locking in the AMD iommu driver.

The iommu_ops::map function (or the iommu_map function which calls it)
was always supposed to be sleepable (according to Joerg's comment in
this thread: https://lore.kernel.org/patchwork/patch/977520/ ) and so
should probably have had a "might_sleep()" since it was written. However
currently the dma-iommu api can call iommu_map in an atomic context,
which it shouldn't do. This doesn't cause any problems because any iommu
driver which uses the dma-iommu api uses gfp_atomic in it's
iommu_ops::map function. But doing this wastes the memory allocators
atomic pools.

Signed-off-by: Tom Murphy <murphyt7@tcd.ie>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync()

To allow IOMMU drivers to batch up TLB flushing operations and postpone
them until ->iotlb_sync() is called, extend the prototypes for the
->unmap() and ->iotlb_sync() IOMMU ops callbacks to take a pointer to
the current iommu_iotlb_gather structure.

All affected IOMMU drivers are updated, but there should be no
functional change since the extra parameter is ignored for now.

Signed-off-by: Will Deacon <will@kernel.org>

iommu/virtio: Update to most recent specification

Following specification review a few things were changed in v8 of the
virtio-iommu series [1], but have been omitted when merging the base
driver. Add them now:

* Remove the EXEC flag.
* Add feature bit for the MMIO flag.
* Change domain_bits to domain_range.
* Add NOMEM status flag.

[1] https://lore.kernel.org/linux-iommu/20190530170929.19366-1-jean-philippe.brucker@arm.com/

Fixes: edcd69ab9a32 ("iommu: Add virtio-iommu driver")
Reported-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Joerg Roedel <jroedel@suse.de>

iommu/virtio: Add event queue

The event queue offers a way for the device to report access faults from
endpoints. It is implemented on virtqueue #1. Whenever the host needs to
signal a fault, it fills one of the buffers offered by the guest and
interrupts it.

Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

iommu/virtio: Add probe request

When the device offers the probe feature, send a probe request for each
device managed by the IOMMU. Extract RESV_MEM information. When we
encounter a MSI doorbell region, set it up as a IOMMU_RESV_MSI region.
This will tell other subsystems that there is no need to map the MSI
doorbell in the virtio-iommu, because MSIs bypass it.

Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

iommu: Add virtio-iommu driver

The virtio IOMMU is a para-virtualized device, allowing to send IOMMU
requests such as map/unmap over virtio transport without emulating page
tables. This implementation handles ATTACH, DETACH, MAP and UNMAP
requests.

The bulk of the code transforms calls coming from the IOMMU API into
corresponding virtio requests. Mappings are kept in an interval tree
instead of page tables. A little more work is required for modular and x86
support, so for the moment the driver depends on CONFIG_VIRTIO=y and
CONFIG_ARM64.

Tested-by: Bharat Bhushan <bharat.bhushan@nxp.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>