<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/vfio, branch v5.4.97</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>vfio iommu: Add dma available capability</title>
<updated>2021-01-17T13:05:30+00:00</updated>
<author>
<name>Matthew Rosato</name>
<email>mjrosato@linux.ibm.com</email>
</author>
<published>2021-01-11T17:31:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5597557244d44989a7310755d0a8ec40ae603acb'/>
<id>5597557244d44989a7310755d0a8ec40ae603acb</id>
<content type='text'>
[ Upstream commit 7d6e1329652ed971d1b6e0e7bea66fba5044e271 ]

The following functional changes were needed for backport:
- vfio_iommu_type1_get_info doesn't exist, call
  vfio_iommu_dma_avail_build_caps from vfio_iommu_type1_ioctl.
- As further fallout from this, vfio_iommu_dma_avail_build_caps must
  acquire and release the iommu mutex lock.  To do so, the return value is
  stored in a local variable as in vfio_iommu_iova_build_caps.

Upstream commit description:
Commit 492855939bdb ("vfio/type1: Limit DMA mappings per container")
added the ability to limit the number of memory backed DMA mappings.
However on s390x, when lazy mapping is in use, we use a very large
number of concurrent mappings.  Let's provide the current allowable
number of DMA mappings to userspace via the IOMMU info chain so that
userspace can take appropriate mitigation.

Signed-off-by: Matthew Rosato &lt;mjrosato@linux.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
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<pre>
[ Upstream commit 7d6e1329652ed971d1b6e0e7bea66fba5044e271 ]

The following functional changes were needed for backport:
- vfio_iommu_type1_get_info doesn't exist, call
  vfio_iommu_dma_avail_build_caps from vfio_iommu_type1_ioctl.
- As further fallout from this, vfio_iommu_dma_avail_build_caps must
  acquire and release the iommu mutex lock.  To do so, the return value is
  stored in a local variable as in vfio_iommu_iova_build_caps.

Upstream commit description:
Commit 492855939bdb ("vfio/type1: Limit DMA mappings per container")
added the ability to limit the number of memory backed DMA mappings.
However on s390x, when lazy mapping is in use, we use a very large
number of concurrent mappings.  Let's provide the current allowable
number of DMA mappings to userspace via the IOMMU info chain so that
userspace can take appropriate mitigation.

Signed-off-by: Matthew Rosato &lt;mjrosato@linux.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/pci: Move dummy_resources_list init in vfio_pci_probe()</title>
<updated>2021-01-06T13:48:36+00:00</updated>
<author>
<name>Eric Auger</name>
<email>eric.auger@redhat.com</email>
</author>
<published>2020-11-13T17:52:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=30aea96ff142fe30545fd2ec071fddddca89ca42'/>
<id>30aea96ff142fe30545fd2ec071fddddca89ca42</id>
<content type='text'>
[ Upstream commit 16b8fe4caf499ae8e12d2ab1b1324497e36a7b83 ]

In case an error occurs in vfio_pci_enable() before the call to
vfio_pci_probe_mmaps(), vfio_pci_disable() will  try to iterate
on an uninitialized list and cause a kernel panic.

Lets move to the initialization to vfio_pci_probe() to fix the
issue.

Signed-off-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Fixes: 05f0c03fbac1 ("vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive")
CC: Stable &lt;stable@vger.kernel.org&gt; # v4.7+
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 16b8fe4caf499ae8e12d2ab1b1324497e36a7b83 ]

In case an error occurs in vfio_pci_enable() before the call to
vfio_pci_probe_mmaps(), vfio_pci_disable() will  try to iterate
on an uninitialized list and cause a kernel panic.

Lets move to the initialization to vfio_pci_probe() to fix the
issue.

Signed-off-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Fixes: 05f0c03fbac1 ("vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive")
CC: Stable &lt;stable@vger.kernel.org&gt; # v4.7+
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/pci/nvlink2: Do not attempt NPU2 setup on POWER8NVL NPU</title>
<updated>2020-12-30T10:51:30+00:00</updated>
<author>
<name>Alexey Kardashevskiy</name>
<email>aik@ozlabs.ru</email>
</author>
<published>2020-11-22T07:39:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f97b54c8152d3f8b23b353397d47fe61b1301cd1'/>
<id>f97b54c8152d3f8b23b353397d47fe61b1301cd1</id>
<content type='text'>
commit d22f9a6c92de96304c81792942ae7c306f08ac77 upstream.

We execute certain NPU2 setup code (such as mapping an LPID to a device
in NPU2) unconditionally if an Nvlink bridge is detected. However this
cannot succeed on POWER8NVL machines as the init helpers return an error
other than ENODEV which means the device is there is and setup failed so
vfio_pci_enable() fails and pass through is not possible.

This changes the two NPU2 related init helpers to return -ENODEV if
there is no "memory-region" device tree property as this is
the distinction between NPU and NPU2.

Tested on
- POWER9 pvr=004e1201, Ubuntu 19.04 host, Ubuntu 18.04 vm,
  NVIDIA GV100 10de:1db1 driver 418.39
- POWER8 pvr=004c0100, RHEL 7.6 host, Ubuntu 16.10 vm,
  NVIDIA P100 10de:15f9 driver 396.47

Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
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<pre>
commit d22f9a6c92de96304c81792942ae7c306f08ac77 upstream.

We execute certain NPU2 setup code (such as mapping an LPID to a device
in NPU2) unconditionally if an Nvlink bridge is detected. However this
cannot succeed on POWER8NVL machines as the init helpers return an error
other than ENODEV which means the device is there is and setup failed so
vfio_pci_enable() fails and pass through is not possible.

This changes the two NPU2 related init helpers to return -ENODEV if
there is no "memory-region" device tree property as this is
the distinction between NPU and NPU2.

Tested on
- POWER9 pvr=004e1201, Ubuntu 19.04 host, Ubuntu 18.04 vm,
  NVIDIA GV100 10de:1db1 driver 418.39
- POWER8 pvr=004c0100, RHEL 7.6 host, Ubuntu 16.10 vm,
  NVIDIA P100 10de:15f9 driver 396.47

Fixes: 7f92891778df ("vfio_pci: Add NVIDIA GV100GL [Tesla V100 SXM2] subdriver")
Cc: stable@vger.kernel.org # 5.0
Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vfio-pci: Use io_remap_pfn_range() for PCI IO memory</title>
<updated>2020-12-30T10:51:16+00:00</updated>
<author>
<name>Jason Gunthorpe</name>
<email>jgg@nvidia.com</email>
</author>
<published>2020-11-05T16:34:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a0f07c9ad72d7ac983cc3ca766b27ff1de63b8c4'/>
<id>a0f07c9ad72d7ac983cc3ca766b27ff1de63b8c4</id>
<content type='text'>
[ Upstream commit 7b06a56d468b756ad6bb43ac21b11e474ebc54a0 ]

commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set
pgprot_decrypted()") allows drivers using mmap to put PCI memory mapped
BAR space into userspace to work correctly on AMD SME systems that default
to all memory encrypted.

Since vfio_pci_mmap_fault() is working with PCI memory mapped BAR space it
should be calling io_remap_pfn_range() otherwise it will not work on SME
systems.

Fixes: 11c4cd07ba11 ("vfio-pci: Fault mmaps to enable vma tracking")
Signed-off-by: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Acked-by: Peter Xu &lt;peterx@redhat.com&gt;
Tested-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
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<pre>
[ Upstream commit 7b06a56d468b756ad6bb43ac21b11e474ebc54a0 ]

commit f8f6ae5d077a ("mm: always have io_remap_pfn_range() set
pgprot_decrypted()") allows drivers using mmap to put PCI memory mapped
BAR space into userspace to work correctly on AMD SME systems that default
to all memory encrypted.

Since vfio_pci_mmap_fault() is working with PCI memory mapped BAR space it
should be calling io_remap_pfn_range() otherwise it will not work on SME
systems.

Fixes: 11c4cd07ba11 ("vfio-pci: Fault mmaps to enable vma tracking")
Signed-off-by: Jason Gunthorpe &lt;jgg@nvidia.com&gt;
Acked-by: Peter Xu &lt;peterx@redhat.com&gt;
Tested-by: Tom Lendacky &lt;thomas.lendacky@amd.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/pci: Bypass IGD init in case of -ENODEV</title>
<updated>2020-11-18T18:20:25+00:00</updated>
<author>
<name>Fred Gao</name>
<email>fred.gao@intel.com</email>
</author>
<published>2020-11-02T18:01:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b66c7cdedd1e9b2bcda3f0cf39a05aa57d3a5948'/>
<id>b66c7cdedd1e9b2bcda3f0cf39a05aa57d3a5948</id>
<content type='text'>
[ Upstream commit e4eccb853664de7bcf9518fb658f35e748bf1f68 ]

Bypass the IGD initialization when -ENODEV returns,
that should be the case if opregion is not available for IGD
or within discrete graphics device's option ROM,
or host/lpc bridge is not found.

Then use of -ENODEV here means no special device resources found
which needs special care for VFIO, but we still allow other normal
device resource access.

Cc: Zhenyu Wang &lt;zhenyuw@linux.intel.com&gt;
Cc: Xiong Zhang &lt;xiong.y.zhang@intel.com&gt;
Cc: Hang Yuan &lt;hang.yuan@linux.intel.com&gt;
Cc: Stuart Summers &lt;stuart.summers@intel.com&gt;
Signed-off-by: Fred Gao &lt;fred.gao@intel.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e4eccb853664de7bcf9518fb658f35e748bf1f68 ]

Bypass the IGD initialization when -ENODEV returns,
that should be the case if opregion is not available for IGD
or within discrete graphics device's option ROM,
or host/lpc bridge is not found.

Then use of -ENODEV here means no special device resources found
which needs special care for VFIO, but we still allow other normal
device resource access.

Cc: Zhenyu Wang &lt;zhenyuw@linux.intel.com&gt;
Cc: Xiong Zhang &lt;xiong.y.zhang@intel.com&gt;
Cc: Hang Yuan &lt;hang.yuan@linux.intel.com&gt;
Cc: Stuart Summers &lt;stuart.summers@intel.com&gt;
Signed-off-by: Fred Gao &lt;fred.gao@intel.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio: platform: fix reference leak in vfio_platform_open</title>
<updated>2020-11-18T18:20:24+00:00</updated>
<author>
<name>Zhang Qilong</name>
<email>zhangqilong3@huawei.com</email>
</author>
<published>2020-10-31T03:03:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c6be53caf1c89ed3346e1d24627fd64093c5bb65'/>
<id>c6be53caf1c89ed3346e1d24627fd64093c5bb65</id>
<content type='text'>
[ Upstream commit bb742ad01961a3b9d1f9d19375487b879668b6b2 ]

pm_runtime_get_sync() will increment pm usage counter even it
failed. Forgetting to call pm_runtime_put will result in
reference leak in vfio_platform_open, so we should fix it.

Signed-off-by: Zhang Qilong &lt;zhangqilong3@huawei.com&gt;
Acked-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bb742ad01961a3b9d1f9d19375487b879668b6b2 ]

pm_runtime_get_sync() will increment pm usage counter even it
failed. Forgetting to call pm_runtime_put will result in
reference leak in vfio_platform_open, so we should fix it.

Signed-off-by: Zhang Qilong &lt;zhangqilong3@huawei.com&gt;
Acked-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio iommu type1: Fix memory leak in vfio_iommu_type1_pin_pages</title>
<updated>2020-10-29T08:57:56+00:00</updated>
<author>
<name>Xiaoyang Xu</name>
<email>xuxiaoyang2@huawei.com</email>
</author>
<published>2020-10-16T09:35:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4035b3d64b650543c11daee6b9b9dd13fbc5bd4'/>
<id>b4035b3d64b650543c11daee6b9b9dd13fbc5bd4</id>
<content type='text'>
[ Upstream commit 2e6cfd496f5b57034cf2aec738799571b5a52124 ]

pfn is not added to pfn_list when vfio_add_to_pfn_list fails.
vfio_unpin_page_external will exit directly without calling
vfio_iova_put_vfio_pfn.  This will lead to a memory leak.

Fixes: a54eb55045ae ("vfio iommu type1: Add support for mediated devices")
Signed-off-by: Xiaoyang Xu &lt;xuxiaoyang2@huawei.com&gt;
[aw: simplified logic, add Fixes]
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2e6cfd496f5b57034cf2aec738799571b5a52124 ]

pfn is not added to pfn_list when vfio_add_to_pfn_list fails.
vfio_unpin_page_external will exit directly without calling
vfio_iova_put_vfio_pfn.  This will lead to a memory leak.

Fixes: a54eb55045ae ("vfio iommu type1: Add support for mediated devices")
Signed-off-by: Xiaoyang Xu &lt;xuxiaoyang2@huawei.com&gt;
[aw: simplified logic, add Fixes]
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/pci: Clear token on bypass registration failure</title>
<updated>2020-10-29T08:57:56+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2020-10-19T13:13:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f54d8a9e37b0a51d43e9572501558a0246cc5004'/>
<id>f54d8a9e37b0a51d43e9572501558a0246cc5004</id>
<content type='text'>
[ Upstream commit 852b1beecb6ff9326f7ca4bc0fe69ae860ebdb9e ]

The eventfd context is used as our irqbypass token, therefore if an
eventfd is re-used, our token is the same.  The irqbypass code will
return an -EBUSY in this case, but we'll still attempt to unregister
the producer, where if that duplicate token still exists, results in
removing the wrong object.  Clear the token of failed producers so
that they harmlessly fall out when unregistered.

Fixes: 6d7425f109d2 ("vfio: Register/unregister irq_bypass_producer")
Reported-by: guomin chen &lt;guomin_chen@sina.com&gt;
Tested-by: guomin chen &lt;guomin_chen@sina.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 852b1beecb6ff9326f7ca4bc0fe69ae860ebdb9e ]

The eventfd context is used as our irqbypass token, therefore if an
eventfd is re-used, our token is the same.  The irqbypass code will
return an -EBUSY in this case, but we'll still attempt to unregister
the producer, where if that duplicate token still exists, results in
removing the wrong object.  Clear the token of failed producers so
that they harmlessly fall out when unregistered.

Fixes: 6d7425f109d2 ("vfio: Register/unregister irq_bypass_producer")
Reported-by: guomin chen &lt;guomin_chen@sina.com&gt;
Tested-by: guomin chen &lt;guomin_chen@sina.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/pci: Decouple PCI_COMMAND_MEMORY bit checks from is_virtfn</title>
<updated>2020-10-29T08:57:54+00:00</updated>
<author>
<name>Matthew Rosato</name>
<email>mjrosato@linux.ibm.com</email>
</author>
<published>2020-09-10T14:59:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fddcf515454e04622d96bb8adabb7e8f3a67ec06'/>
<id>fddcf515454e04622d96bb8adabb7e8f3a67ec06</id>
<content type='text'>
[ Upstream commit 515ecd5368f1510152fa4f9b9ce55b66ac56c334 ]

While it is true that devices with is_virtfn=1 will have a Memory Space
Enable bit that is hard-wired to 0, this is not the only case where we
see this behavior -- For example some bare-metal hypervisors lack
Memory Space Enable bit emulation for devices not setting is_virtfn
(s390). Fix this by instead checking for the newly-added
no_command_memory bit which directly denotes the need for
PCI_COMMAND_MEMORY emulation in vfio.

Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory")
Signed-off-by: Matthew Rosato &lt;mjrosato@linux.ibm.com&gt;
Reviewed-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Reviewed-by: Pierre Morel &lt;pmorel@linux.ibm.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 515ecd5368f1510152fa4f9b9ce55b66ac56c334 ]

While it is true that devices with is_virtfn=1 will have a Memory Space
Enable bit that is hard-wired to 0, this is not the only case where we
see this behavior -- For example some bare-metal hypervisors lack
Memory Space Enable bit emulation for devices not setting is_virtfn
(s390). Fix this by instead checking for the newly-added
no_command_memory bit which directly denotes the need for
PCI_COMMAND_MEMORY emulation in vfio.

Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory")
Signed-off-by: Matthew Rosato &lt;mjrosato@linux.ibm.com&gt;
Reviewed-by: Niklas Schnelle &lt;schnelle@linux.ibm.com&gt;
Reviewed-by: Pierre Morel &lt;pmorel@linux.ibm.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/pci: fix racy on error and request eventfd ctx</title>
<updated>2020-10-01T11:18:10+00:00</updated>
<author>
<name>Zeng Tao</name>
<email>prime.zeng@hisilicon.com</email>
</author>
<published>2020-07-15T07:34:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=af60d80598b3c18abf250dfd0d4039be3846b4b9'/>
<id>af60d80598b3c18abf250dfd0d4039be3846b4b9</id>
<content type='text'>
[ Upstream commit b872d0640840018669032b20b6375a478ed1f923 ]

The vfio_pci_release call will free and clear the error and request
eventfd ctx while these ctx could be in use at the same time in the
function like vfio_pci_request, and it's expected to protect them under
the vdev-&gt;igate mutex, which is missing in vfio_pci_release.

This issue is introduced since commit 1518ac272e78 ("vfio/pci: fix memory
leaks of eventfd ctx"),and since commit 5c5866c593bb ("vfio/pci: Clear
error and request eventfd ctx after releasing"), it's very easily to
trigger the kernel panic like this:

[ 9513.904346] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
[ 9513.913091] Mem abort info:
[ 9513.915871]   ESR = 0x96000006
[ 9513.918912]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 9513.924198]   SET = 0, FnV = 0
[ 9513.927238]   EA = 0, S1PTW = 0
[ 9513.930364] Data abort info:
[ 9513.933231]   ISV = 0, ISS = 0x00000006
[ 9513.937048]   CM = 0, WnR = 0
[ 9513.940003] user pgtable: 4k pages, 48-bit VAs, pgdp=0000007ec7d12000
[ 9513.946414] [0000000000000008] pgd=0000007ec7d13003, p4d=0000007ec7d13003, pud=0000007ec728c003, pmd=0000000000000000
[ 9513.956975] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[ 9513.962521] Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio hclge hns3 hnae3 [last unloaded: vfio_pci]
[ 9513.972998] CPU: 4 PID: 1327 Comm: bash Tainted: G        W         5.8.0-rc4+ #3
[ 9513.980443] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B270.01 05/08/2020
[ 9513.989274] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--)
[ 9513.994827] pc : _raw_spin_lock_irqsave+0x48/0x88
[ 9513.999515] lr : eventfd_signal+0x6c/0x1b0
[ 9514.003591] sp : ffff800038a0b960
[ 9514.006889] x29: ffff800038a0b960 x28: ffff007ef7f4da10
[ 9514.012175] x27: ffff207eefbbfc80 x26: ffffbb7903457000
[ 9514.017462] x25: ffffbb7912191000 x24: ffff007ef7f4d400
[ 9514.022747] x23: ffff20be6e0e4c00 x22: 0000000000000008
[ 9514.028033] x21: 0000000000000000 x20: 0000000000000000
[ 9514.033321] x19: 0000000000000008 x18: 0000000000000000
[ 9514.038606] x17: 0000000000000000 x16: ffffbb7910029328
[ 9514.043893] x15: 0000000000000000 x14: 0000000000000001
[ 9514.049179] x13: 0000000000000000 x12: 0000000000000002
[ 9514.054466] x11: 0000000000000000 x10: 0000000000000a00
[ 9514.059752] x9 : ffff800038a0b840 x8 : ffff007ef7f4de60
[ 9514.065038] x7 : ffff007fffc96690 x6 : fffffe01faffb748
[ 9514.070324] x5 : 0000000000000000 x4 : 0000000000000000
[ 9514.075609] x3 : 0000000000000000 x2 : 0000000000000001
[ 9514.080895] x1 : ffff007ef7f4d400 x0 : 0000000000000000
[ 9514.086181] Call trace:
[ 9514.088618]  _raw_spin_lock_irqsave+0x48/0x88
[ 9514.092954]  eventfd_signal+0x6c/0x1b0
[ 9514.096691]  vfio_pci_request+0x84/0xd0 [vfio_pci]
[ 9514.101464]  vfio_del_group_dev+0x150/0x290 [vfio]
[ 9514.106234]  vfio_pci_remove+0x30/0x128 [vfio_pci]
[ 9514.111007]  pci_device_remove+0x48/0x108
[ 9514.115001]  device_release_driver_internal+0x100/0x1b8
[ 9514.120200]  device_release_driver+0x28/0x38
[ 9514.124452]  pci_stop_bus_device+0x68/0xa8
[ 9514.128528]  pci_stop_and_remove_bus_device+0x20/0x38
[ 9514.133557]  pci_iov_remove_virtfn+0xb4/0x128
[ 9514.137893]  sriov_disable+0x3c/0x108
[ 9514.141538]  pci_disable_sriov+0x28/0x38
[ 9514.145445]  hns3_pci_sriov_configure+0x48/0xb8 [hns3]
[ 9514.150558]  sriov_numvfs_store+0x110/0x198
[ 9514.154724]  dev_attr_store+0x44/0x60
[ 9514.158373]  sysfs_kf_write+0x5c/0x78
[ 9514.162018]  kernfs_fop_write+0x104/0x210
[ 9514.166010]  __vfs_write+0x48/0x90
[ 9514.169395]  vfs_write+0xbc/0x1c0
[ 9514.172694]  ksys_write+0x74/0x100
[ 9514.176079]  __arm64_sys_write+0x24/0x30
[ 9514.179987]  el0_svc_common.constprop.4+0x110/0x200
[ 9514.184842]  do_el0_svc+0x34/0x98
[ 9514.188144]  el0_svc+0x14/0x40
[ 9514.191185]  el0_sync_handler+0xb0/0x2d0
[ 9514.195088]  el0_sync+0x140/0x180
[ 9514.198389] Code: b9001020 d2800000 52800022 f9800271 (885ffe61)
[ 9514.204455] ---[ end trace 648de00c8406465f ]---
[ 9514.212308] note: bash[1327] exited with preempt_count 1

Cc: Qian Cai &lt;cai@lca.pw&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx")
Signed-off-by: Zeng Tao &lt;prime.zeng@hisilicon.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b872d0640840018669032b20b6375a478ed1f923 ]

The vfio_pci_release call will free and clear the error and request
eventfd ctx while these ctx could be in use at the same time in the
function like vfio_pci_request, and it's expected to protect them under
the vdev-&gt;igate mutex, which is missing in vfio_pci_release.

This issue is introduced since commit 1518ac272e78 ("vfio/pci: fix memory
leaks of eventfd ctx"),and since commit 5c5866c593bb ("vfio/pci: Clear
error and request eventfd ctx after releasing"), it's very easily to
trigger the kernel panic like this:

[ 9513.904346] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
[ 9513.913091] Mem abort info:
[ 9513.915871]   ESR = 0x96000006
[ 9513.918912]   EC = 0x25: DABT (current EL), IL = 32 bits
[ 9513.924198]   SET = 0, FnV = 0
[ 9513.927238]   EA = 0, S1PTW = 0
[ 9513.930364] Data abort info:
[ 9513.933231]   ISV = 0, ISS = 0x00000006
[ 9513.937048]   CM = 0, WnR = 0
[ 9513.940003] user pgtable: 4k pages, 48-bit VAs, pgdp=0000007ec7d12000
[ 9513.946414] [0000000000000008] pgd=0000007ec7d13003, p4d=0000007ec7d13003, pud=0000007ec728c003, pmd=0000000000000000
[ 9513.956975] Internal error: Oops: 96000006 [#1] PREEMPT SMP
[ 9513.962521] Modules linked in: vfio_pci vfio_virqfd vfio_iommu_type1 vfio hclge hns3 hnae3 [last unloaded: vfio_pci]
[ 9513.972998] CPU: 4 PID: 1327 Comm: bash Tainted: G        W         5.8.0-rc4+ #3
[ 9513.980443] Hardware name: Huawei TaiShan 2280 V2/BC82AMDC, BIOS 2280-V2 CS V3.B270.01 05/08/2020
[ 9513.989274] pstate: 80400089 (Nzcv daIf +PAN -UAO BTYPE=--)
[ 9513.994827] pc : _raw_spin_lock_irqsave+0x48/0x88
[ 9513.999515] lr : eventfd_signal+0x6c/0x1b0
[ 9514.003591] sp : ffff800038a0b960
[ 9514.006889] x29: ffff800038a0b960 x28: ffff007ef7f4da10
[ 9514.012175] x27: ffff207eefbbfc80 x26: ffffbb7903457000
[ 9514.017462] x25: ffffbb7912191000 x24: ffff007ef7f4d400
[ 9514.022747] x23: ffff20be6e0e4c00 x22: 0000000000000008
[ 9514.028033] x21: 0000000000000000 x20: 0000000000000000
[ 9514.033321] x19: 0000000000000008 x18: 0000000000000000
[ 9514.038606] x17: 0000000000000000 x16: ffffbb7910029328
[ 9514.043893] x15: 0000000000000000 x14: 0000000000000001
[ 9514.049179] x13: 0000000000000000 x12: 0000000000000002
[ 9514.054466] x11: 0000000000000000 x10: 0000000000000a00
[ 9514.059752] x9 : ffff800038a0b840 x8 : ffff007ef7f4de60
[ 9514.065038] x7 : ffff007fffc96690 x6 : fffffe01faffb748
[ 9514.070324] x5 : 0000000000000000 x4 : 0000000000000000
[ 9514.075609] x3 : 0000000000000000 x2 : 0000000000000001
[ 9514.080895] x1 : ffff007ef7f4d400 x0 : 0000000000000000
[ 9514.086181] Call trace:
[ 9514.088618]  _raw_spin_lock_irqsave+0x48/0x88
[ 9514.092954]  eventfd_signal+0x6c/0x1b0
[ 9514.096691]  vfio_pci_request+0x84/0xd0 [vfio_pci]
[ 9514.101464]  vfio_del_group_dev+0x150/0x290 [vfio]
[ 9514.106234]  vfio_pci_remove+0x30/0x128 [vfio_pci]
[ 9514.111007]  pci_device_remove+0x48/0x108
[ 9514.115001]  device_release_driver_internal+0x100/0x1b8
[ 9514.120200]  device_release_driver+0x28/0x38
[ 9514.124452]  pci_stop_bus_device+0x68/0xa8
[ 9514.128528]  pci_stop_and_remove_bus_device+0x20/0x38
[ 9514.133557]  pci_iov_remove_virtfn+0xb4/0x128
[ 9514.137893]  sriov_disable+0x3c/0x108
[ 9514.141538]  pci_disable_sriov+0x28/0x38
[ 9514.145445]  hns3_pci_sriov_configure+0x48/0xb8 [hns3]
[ 9514.150558]  sriov_numvfs_store+0x110/0x198
[ 9514.154724]  dev_attr_store+0x44/0x60
[ 9514.158373]  sysfs_kf_write+0x5c/0x78
[ 9514.162018]  kernfs_fop_write+0x104/0x210
[ 9514.166010]  __vfs_write+0x48/0x90
[ 9514.169395]  vfs_write+0xbc/0x1c0
[ 9514.172694]  ksys_write+0x74/0x100
[ 9514.176079]  __arm64_sys_write+0x24/0x30
[ 9514.179987]  el0_svc_common.constprop.4+0x110/0x200
[ 9514.184842]  do_el0_svc+0x34/0x98
[ 9514.188144]  el0_svc+0x14/0x40
[ 9514.191185]  el0_sync_handler+0xb0/0x2d0
[ 9514.195088]  el0_sync+0x140/0x180
[ 9514.198389] Code: b9001020 d2800000 52800022 f9800271 (885ffe61)
[ 9514.204455] ---[ end trace 648de00c8406465f ]---
[ 9514.212308] note: bash[1327] exited with preempt_count 1

Cc: Qian Cai &lt;cai@lca.pw&gt;
Cc: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Fixes: 1518ac272e78 ("vfio/pci: fix memory leaks of eventfd ctx")
Signed-off-by: Zeng Tao &lt;prime.zeng@hisilicon.com&gt;
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
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