linux-stable.git/drivers/virtio, branch v4.9.8 Linux kernel stable tree virtio_mmio: Set DMA masks appropriately 2017-02-01T07:33:13+00:00 Robin Murphy robin.murphy@arm.com 2017-01-10T17:51:17+00:00 776050a9b55e17b72b5684794b9580d72e920e17 commit f7f6634d23830ff74335734fbdb28ea109c1f349 upstream. Once DMA API usage is enabled, it becomes apparent that virtio-mmio is inadvertently relying on the default 32-bit DMA mask, which leads to problems like rapidly exhausting SWIOTLB bounce buffers. Ensure that we set the appropriate 64-bit DMA mask whenever possible, with the coherent mask suitably limited for the legacy vring as per a0be1db4304f ("virtio_pci: Limit DMA mask to 44 bits for legacy virtio devices"). Cc: Andy Lutomirski <luto@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Reported-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Fixes: b42111382f0e ("virtio_mmio: Use the DMA API if enabled") Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f7f6634d23830ff74335734fbdb28ea109c1f349 upstream.

Once DMA API usage is enabled, it becomes apparent that virtio-mmio is
inadvertently relying on the default 32-bit DMA mask, which leads to
problems like rapidly exhausting SWIOTLB bounce buffers.

Ensure that we set the appropriate 64-bit DMA mask whenever possible,
with the coherent mask suitably limited for the legacy vring as per
a0be1db4304f ("virtio_pci: Limit DMA mask to 44 bits for legacy virtio
devices").

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Fixes: b42111382f0e ("virtio_mmio: Use the DMA API if enabled")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
vring: Force use of DMA API for ARM-based systems with legacy devices 2017-02-01T07:33:05+00:00 Will Deacon will.deacon@arm.com 2017-01-20T10:33:32+00:00 13e39d5930ec5a4e0711a6d88bcea84bfd13d4bb commit c7070619f3408d9a0dffbed9149e6f00479cf43b upstream. Booting Linux on an ARM fastmodel containing an SMMU emulation results in an unexpected I/O page fault from the legacy virtio-blk PCI device: [ 1.211721] arm-smmu-v3 2b400000.smmu: event 0x10 received: [ 1.211800] arm-smmu-v3 2b400000.smmu: 0x00000000fffff010 [ 1.211880] arm-smmu-v3 2b400000.smmu: 0x0000020800000000 [ 1.211959] arm-smmu-v3 2b400000.smmu: 0x00000008fa081002 [ 1.212075] arm-smmu-v3 2b400000.smmu: 0x0000000000000000 [ 1.212155] arm-smmu-v3 2b400000.smmu: event 0x10 received: [ 1.212234] arm-smmu-v3 2b400000.smmu: 0x00000000fffff010 [ 1.212314] arm-smmu-v3 2b400000.smmu: 0x0000020800000000 [ 1.212394] arm-smmu-v3 2b400000.smmu: 0x00000008fa081000 [ 1.212471] arm-smmu-v3 2b400000.smmu: 0x0000000000000000 <system hangs failing to read partition table> This is because the legacy virtio-blk device is behind an SMMU, so we have consequently swizzled its DMA ops and configured the SMMU to translate accesses. This then requires the vring code to use the DMA API to establish translations, otherwise all transactions will result in fatal faults and termination. Given that ARM-based systems only see an SMMU if one is really present (the topology is all described by firmware tables such as device-tree or IORT), then we can safely use the DMA API for all legacy virtio devices. Modern devices can advertise the prescense of an IOMMU using the VIRTIO_F_IOMMU_PLATFORM feature flag. Cc: Andy Lutomirski <luto@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Fixes: 876945dbf649 ("arm64: Hook up IOMMU dma_ops") Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c7070619f3408d9a0dffbed9149e6f00479cf43b upstream.

Booting Linux on an ARM fastmodel containing an SMMU emulation results
in an unexpected I/O page fault from the legacy virtio-blk PCI device:

[    1.211721] arm-smmu-v3 2b400000.smmu: event 0x10 received:
[    1.211800] arm-smmu-v3 2b400000.smmu:	0x00000000fffff010
[    1.211880] arm-smmu-v3 2b400000.smmu:	0x0000020800000000
[    1.211959] arm-smmu-v3 2b400000.smmu:	0x00000008fa081002
[    1.212075] arm-smmu-v3 2b400000.smmu:	0x0000000000000000
[    1.212155] arm-smmu-v3 2b400000.smmu: event 0x10 received:
[    1.212234] arm-smmu-v3 2b400000.smmu:	0x00000000fffff010
[    1.212314] arm-smmu-v3 2b400000.smmu:	0x0000020800000000
[    1.212394] arm-smmu-v3 2b400000.smmu:	0x00000008fa081000
[    1.212471] arm-smmu-v3 2b400000.smmu:	0x0000000000000000

<system hangs failing to read partition table>

This is because the legacy virtio-blk device is behind an SMMU, so we
have consequently swizzled its DMA ops and configured the SMMU to
translate accesses. This then requires the vring code to use the DMA API
to establish translations, otherwise all transactions will result in
fatal faults and termination.

Given that ARM-based systems only see an SMMU if one is really present
(the topology is all described by firmware tables such as device-tree or
IORT), then we can safely use the DMA API for all legacy virtio devices.
Modern devices can advertise the prescense of an IOMMU using the
VIRTIO_F_IOMMU_PLATFORM feature flag.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Fixes: 876945dbf649 ("arm64: Hook up IOMMU dma_ops")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
virtio_ring: mark vring_dma_dev inline 2016-10-30T22:40:08+00:00 Michael S. Tsirkin mst@redhat.com 2016-10-30T22:38:21+00:00 75bfa81bf0897ba87f1e1b9b576a07536029b86a This inline function is unused on configurations where dma_map/unmap are empty macros. Make the function inline to avoid gcc errors because of an unused static function. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
This inline function is unused on configurations
where dma_map/unmap are empty macros.

Make the function inline to avoid gcc errors because
of an unused static function.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio: remove config.c 2016-10-30T22:21:45+00:00 Juergen Gross jgross@suse.com 2016-10-11T09:02:14+00:00 3dae2c6152fbbc6224343551158b61aad585cedf Remove unused file config.c Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
Remove unused file config.c

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio: update balloon size in balloon "probe" 2016-10-30T22:21:41+00:00 Konstantin Neumoin kneumoin@virtuozzo.com 2016-09-29T10:17:12+00:00 8424af5336b34043a705d66bdf2c1428048ef085 The following commit 'fad7b7b27b6a (virtio_balloon: Use a workqueue instead of "vballoon" kthread)' has added a regression. Original code with kthread starts the thread inside probe and checks the necessity to update balloon inside the thread immediately. Nowadays the code behaves differently. Work is queued only on the first command from the host after the negotiation. Thus there is a window especially at the guest startup or the module reloading when the balloon size is not updated until the notification from the host. This patch adds balloon size check at the end of the probe to match original behaviour. Signed-off-by: Konstantin Neumoin <kneumoin@virtuozzo.com> Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
The following commit 'fad7b7b27b6a (virtio_balloon: Use a workqueue
instead of "vballoon" kthread)' has added a regression. Original code with
kthread starts the thread inside probe and checks the necessity to update
balloon inside the thread immediately.

Nowadays the code behaves differently. Work is queued only on the first
command from the host after the negotiation. Thus there is a window
especially at the guest startup or the module reloading when the balloon
size is not updated until the notification from the host.

This patch adds balloon size check at the end of the probe to match
original behaviour.

Signed-off-by: Konstantin Neumoin <kneumoin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio_ring: Make interrupt suppression spec compliant 2016-10-30T22:21:40+00:00 Ladi Prosek lprosek@redhat.com 2016-08-31T12:00:04+00:00 0ea1e4a6d9b62cf29e210d2b4ba9fd43917522e3 According to the spec, if the VIRTIO_RING_F_EVENT_IDX feature bit is negotiated the driver MUST set flags to 0. Not dirtying the available ring in virtqueue_disable_cb also has a minor positive performance impact, improving L1 dcache load missed by ~0.5% in vring_bench. Writes to the used event field (vring_used_event) are still unconditional. Cc: Michael S. Tsirkin <mst@redhat.com> Cc: <stable@vger.kernel.org> # f277ec4 virtio_ring: shadow available Cc: <stable@vger.kernel.org> Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
According to the spec, if the VIRTIO_RING_F_EVENT_IDX feature bit is
negotiated the driver MUST set flags to 0. Not dirtying the available
ring in virtqueue_disable_cb also has a minor positive performance
impact, improving L1 dcache load missed by ~0.5% in vring_bench.

Writes to the used event field (vring_used_event) are still unconditional.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: <stable@vger.kernel.org> # f277ec4 virtio_ring: shadow available
Cc: <stable@vger.kernel.org>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio_pci: Limit DMA mask to 44 bits for legacy virtio devices 2016-10-30T22:21:39+00:00 Will Deacon will.deacon@arm.com 2016-09-14T16:33:26+00:00 a0be1db4304f51c99af6b6e515549794182a94df Legacy virtio defines the virtqueue base using a 32-bit PFN field, with a read-only register indicating a fixed page size of 4k. This can cause problems for DMA allocators that allocate top down from the DMA mask, which is set to 64 bits. In this case, the addresses are silently truncated to 44-bit, leading to IOMMU faults, failure to read from the queue or data corruption. This patch restricts the coherent DMA mask for legacy PCI virtio devices to 44 bits, which matches the specification. Cc: stable@vger.kernel.org Cc: Andy Lutomirski <luto@kernel.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Benjamin Serebrin <serebrin@google.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
Legacy virtio defines the virtqueue base using a 32-bit PFN field, with
a read-only register indicating a fixed page size of 4k.

This can cause problems for DMA allocators that allocate top down from
the DMA mask, which is set to 64 bits. In this case, the addresses are
silently truncated to 44-bit, leading to IOMMU faults, failure to read
from the queue or data corruption.

This patch restricts the coherent DMA mask for legacy PCI virtio devices
to 44 bits, which matches the specification.

Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Benjamin Serebrin <serebrin@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio: mark vring_dma_dev() static 2016-09-09T18:12:35+00:00 Baoyou Xie baoyou.xie@linaro.org 2016-09-01T11:02:57+00:00 af7c1beccfd98bad752644dc14ea93805d65b2c9 We get 1 warning when building kernel with W=1: drivers/virtio/virtio_ring.c:170:16: warning: no previous prototype for 'vring_dma_dev' [-Wmissing-prototypes] In fact, this function is only used in the file in which it is declared and don't need a declaration, but can be made static. so this patch marks this function with 'static'. Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
We get 1 warning when building kernel with W=1:
drivers/virtio/virtio_ring.c:170:16: warning: no previous prototype for 'vring_dma_dev' [-Wmissing-prototypes]

In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
so this patch marks this function with 'static'.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio: fix error handling for debug builds 2016-08-09T10:42:35+00:00 Michael S. Tsirkin mst@redhat.com 2016-08-03T04:18:51+00:00 3cc36f6e34bd2d92d23be7b598ba5e639c47b01a On error, virtqueue_add calls START_USE but not END_USE. Thankfully that's normally empty anyway, but might not be when debugging. Fix it up. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
On error, virtqueue_add calls START_USE but not
END_USE. Thankfully that's normally empty anyway,
but might not be when debugging. Fix it up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
virtio: fix memory leak in virtqueue_add() 2016-08-09T10:42:34+00:00 Wei Yongjun weiyj.lk@gmail.com 2016-08-02T14:16:31+00:00 58625edf9e2515ed41dac2a24fa8004030a87b87 When using the indirect buffers feature, 'desc' is allocated in virtqueue_add() but isn't freed before leaving on a ring full error, causing a memory leak. For example, it seems rather clear that this can trigger with virtio net if mergeable buffers are not used. Cc: stable@vger.kernel.org Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> 
When using the indirect buffers feature, 'desc' is allocated in
virtqueue_add() but isn't freed before leaving on a ring full error,
causing a memory leak.

For example, it seems rather clear that this can trigger
with virtio net if mergeable buffers are not used.

Cc: stable@vger.kernel.org
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>