<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/vfio, branch v6.8.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>vfio/pds: Make sure migration file isn't accessed after reset</title>
<updated>2024-04-03T13:32:44+00:00</updated>
<author>
<name>Brett Creeley</name>
<email>brett.creeley@amd.com</email>
</author>
<published>2024-03-08T18:21:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=17cf7f9a944826532bfc495bb06900ba13949d84'/>
<id>17cf7f9a944826532bfc495bb06900ba13949d84</id>
<content type='text'>
[ Upstream commit 457f7308254756b6e4b8fc3876cb770dcf0e7cc7 ]

It's possible the migration file is accessed after reset when it has
been cleaned up, especially when it's initiated by the device. This is
because the driver doesn't rip out the filep when cleaning up it only
frees the related page structures and sets its local struct
pds_vfio_lm_file pointer to NULL. This can cause a NULL pointer
dereference, which is shown in the example below during a restore after
a device initiated reset:

BUG: kernel NULL pointer dereference, address: 000000000000000c
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:pds_vfio_get_file_page+0x5d/0xf0 [pds_vfio_pci]
[...]
Call Trace:
 &lt;TASK&gt;
 pds_vfio_restore_write+0xf6/0x160 [pds_vfio_pci]
 vfs_write+0xc9/0x3f0
 ? __fget_light+0xc9/0x110
 ksys_write+0xb5/0xf0
 __x64_sys_write+0x1a/0x20
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]

Add a disabled flag to the driver's struct pds_vfio_lm_file that gets
set during cleanup. Then make sure to check the flag when the migration
file is accessed via its file_operations. By default this flag will be
false as the memory for struct pds_vfio_lm_file is kzalloc'd, which means
the struct pds_vfio_lm_file is enabled and accessible. Also, since the
file_operations and driver's migration file cleanup happen under the
protection of the same pds_vfio_lm_file.lock, using this flag is thread
safe.

Fixes: 8512ed256334 ("vfio/pds: Always clear the save/restore FDs on reset")
Reviewed-by: Shannon Nelson &lt;shannon.nelson@amd.com&gt;
Signed-off-by: Brett Creeley &lt;brett.creeley@amd.com&gt;
Link: https://lore.kernel.org/r/20240308182149.22036-2-brett.creeley@amd.com
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 457f7308254756b6e4b8fc3876cb770dcf0e7cc7 ]

It's possible the migration file is accessed after reset when it has
been cleaned up, especially when it's initiated by the device. This is
because the driver doesn't rip out the filep when cleaning up it only
frees the related page structures and sets its local struct
pds_vfio_lm_file pointer to NULL. This can cause a NULL pointer
dereference, which is shown in the example below during a restore after
a device initiated reset:

BUG: kernel NULL pointer dereference, address: 000000000000000c
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:pds_vfio_get_file_page+0x5d/0xf0 [pds_vfio_pci]
[...]
Call Trace:
 &lt;TASK&gt;
 pds_vfio_restore_write+0xf6/0x160 [pds_vfio_pci]
 vfs_write+0xc9/0x3f0
 ? __fget_light+0xc9/0x110
 ksys_write+0xb5/0xf0
 __x64_sys_write+0x1a/0x20
 do_syscall_64+0x38/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]

Add a disabled flag to the driver's struct pds_vfio_lm_file that gets
set during cleanup. Then make sure to check the flag when the migration
file is accessed via its file_operations. By default this flag will be
false as the memory for struct pds_vfio_lm_file is kzalloc'd, which means
the struct pds_vfio_lm_file is enabled and accessible. Also, since the
file_operations and driver's migration file cleanup happen under the
protection of the same pds_vfio_lm_file.lock, using this flag is thread
safe.

Fixes: 8512ed256334 ("vfio/pds: Always clear the save/restore FDs on reset")
Reviewed-by: Shannon Nelson &lt;shannon.nelson@amd.com&gt;
Signed-off-by: Brett Creeley &lt;brett.creeley@amd.com&gt;
Link: https://lore.kernel.org/r/20240308182149.22036-2-brett.creeley@amd.com
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: Create persistent INTx handler</title>
<updated>2024-04-03T13:32:30+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0e09cf81959d9f12b75ad5c6dd53d237432ed034'/>
<id>0e09cf81959d9f12b75ad5c6dd53d237432ed034</id>
<content type='text'>
[ Upstream commit 18c198c96a815c962adc2b9b77909eec0be7df4d ]

A vulnerability exists where the eventfd for INTx signaling can be
deconfigured, which unregisters the IRQ handler but still allows
eventfds to be signaled with a NULL context through the SET_IRQS ioctl
or through unmask irqfd if the device interrupt is pending.

Ideally this could be solved with some additional locking; the igate
mutex serializes the ioctl and config space accesses, and the interrupt
handler is unregistered relative to the trigger, but the irqfd path
runs asynchronous to those.  The igate mutex cannot be acquired from the
atomic context of the eventfd wake function.  Disabling the irqfd
relative to the eventfd registration is potentially incompatible with
existing userspace.

As a result, the solution implemented here moves configuration of the
INTx interrupt handler to track the lifetime of the INTx context object
and irq_type configuration, rather than registration of a particular
trigger eventfd.  Synchronization is added between the ioctl path and
eventfd_signal() wrapper such that the eventfd trigger can be
dynamically updated relative to in-flight interrupts or irqfd callbacks.

Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-5-alex.williamson@redhat.com
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 18c198c96a815c962adc2b9b77909eec0be7df4d ]

A vulnerability exists where the eventfd for INTx signaling can be
deconfigured, which unregisters the IRQ handler but still allows
eventfds to be signaled with a NULL context through the SET_IRQS ioctl
or through unmask irqfd if the device interrupt is pending.

Ideally this could be solved with some additional locking; the igate
mutex serializes the ioctl and config space accesses, and the interrupt
handler is unregistered relative to the trigger, but the irqfd path
runs asynchronous to those.  The igate mutex cannot be acquired from the
atomic context of the eventfd wake function.  Disabling the irqfd
relative to the eventfd registration is potentially incompatible with
existing userspace.

As a result, the solution implemented here moves configuration of the
INTx interrupt handler to track the lifetime of the INTx context object
and irq_type configuration, rather than registration of a particular
trigger eventfd.  Synchronization is added between the ioctl path and
eventfd_signal() wrapper such that the eventfd trigger can be
dynamically updated relative to in-flight interrupts or irqfd callbacks.

Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-5-alex.williamson@redhat.com
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: Introduce interface to flush virqfd inject workqueue</title>
<updated>2024-04-03T13:32:30+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8215d352bb08fa32e9382bf0b16d9c9e145723e0'/>
<id>8215d352bb08fa32e9382bf0b16d9c9e145723e0</id>
<content type='text'>
[ Upstream commit b620ecbd17a03cacd06f014a5d3f3a11285ce053 ]

In order to synchronize changes that can affect the thread callback,
introduce an interface to force a flush of the inject workqueue.  The
irqfd pointer is only valid under spinlock, but the workqueue cannot
be flushed under spinlock.  Therefore the flush work for the irqfd is
queued under spinlock.  The vfio_irqfd_cleanup_wq workqueue is re-used
for queuing this work such that flushing the workqueue is also ordered
relative to shutdown.

Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-4-alex.williamson@redhat.com
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Stable-dep-of: 18c198c96a81 ("vfio/pci: Create persistent INTx handler")
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 b620ecbd17a03cacd06f014a5d3f3a11285ce053 ]

In order to synchronize changes that can affect the thread callback,
introduce an interface to force a flush of the inject workqueue.  The
irqfd pointer is only valid under spinlock, but the workqueue cannot
be flushed under spinlock.  Therefore the flush work for the irqfd is
queued under spinlock.  The vfio_irqfd_cleanup_wq workqueue is re-used
for queuing this work such that flushing the workqueue is also ordered
relative to shutdown.

Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-4-alex.williamson@redhat.com
Signed-off-by: Alex Williamson &lt;alex.williamson@redhat.com&gt;
Stable-dep-of: 18c198c96a81 ("vfio/pci: Create persistent INTx handler")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vfio/fsl-mc: Block calling interrupt handler without trigger</title>
<updated>2024-04-03T13:32:19+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6ec0d88166dac43f29e96801c0927d514f17add9'/>
<id>6ec0d88166dac43f29e96801c0927d514f17add9</id>
<content type='text'>
[ Upstream commit 7447d911af699a15f8d050dfcb7c680a86f87012 ]

The eventfd_ctx trigger pointer of the vfio_fsl_mc_irq object is
initially NULL and may become NULL if the user sets the trigger
eventfd to -1.  The interrupt handler itself is guaranteed that
trigger is always valid between request_irq() and free_irq(), but
the loopback testing mechanisms to invoke the handler function
need to test the trigger.  The triggering and setting ioctl paths
both make use of igate and are therefore mutually exclusive.

The vfio-fsl-mc driver does not make use of irqfds, nor does it
support any sort of masking operations, therefore unlike vfio-pci
and vfio-platform, the flow can remain essentially unchanged.

Cc: Diana Craciun &lt;diana.craciun@oss.nxp.com&gt;
Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: cc0ee20bd969 ("vfio/fsl-mc: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-8-alex.williamson@redhat.com
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 7447d911af699a15f8d050dfcb7c680a86f87012 ]

The eventfd_ctx trigger pointer of the vfio_fsl_mc_irq object is
initially NULL and may become NULL if the user sets the trigger
eventfd to -1.  The interrupt handler itself is guaranteed that
trigger is always valid between request_irq() and free_irq(), but
the loopback testing mechanisms to invoke the handler function
need to test the trigger.  The triggering and setting ioctl paths
both make use of igate and are therefore mutually exclusive.

The vfio-fsl-mc driver does not make use of irqfds, nor does it
support any sort of masking operations, therefore unlike vfio-pci
and vfio-platform, the flow can remain essentially unchanged.

Cc: Diana Craciun &lt;diana.craciun@oss.nxp.com&gt;
Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: cc0ee20bd969 ("vfio/fsl-mc: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-8-alex.williamson@redhat.com
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: Create persistent IRQ handlers</title>
<updated>2024-04-03T13:32:19+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0f8d8f9c2173a541812dd750529f4a415117eb29'/>
<id>0f8d8f9c2173a541812dd750529f4a415117eb29</id>
<content type='text'>
[ Upstream commit 675daf435e9f8e5a5eab140a9864dfad6668b375 ]

The vfio-platform SET_IRQS ioctl currently allows loopback triggering of
an interrupt before a signaling eventfd has been configured by the user,
which thereby allows a NULL pointer dereference.

Rather than register the IRQ relative to a valid trigger, register all
IRQs in a disabled state in the device open path.  This allows mask
operations on the IRQ to nest within the overall enable state governed
by a valid eventfd signal.  This decouples @masked, protected by the
@locked spinlock from @trigger, protected via the @igate mutex.

In doing so, it's guaranteed that changes to @trigger cannot race the
IRQ handlers because the IRQ handler is synchronously disabled before
modifying the trigger, and loopback triggering of the IRQ via ioctl is
safe due to serialization with trigger changes via igate.

For compatibility, request_irq() failures are maintained to be local to
the SET_IRQS ioctl rather than a fatal error in the open device path.
This allows, for example, a userspace driver with polling mode support
to continue to work regardless of moving the request_irq() call site.
This necessarily blocks all SET_IRQS access to the failed index.

Cc: Eric Auger &lt;eric.auger@redhat.com&gt;
Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 57f972e2b341 ("vfio/platform: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-7-alex.williamson@redhat.com
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 675daf435e9f8e5a5eab140a9864dfad6668b375 ]

The vfio-platform SET_IRQS ioctl currently allows loopback triggering of
an interrupt before a signaling eventfd has been configured by the user,
which thereby allows a NULL pointer dereference.

Rather than register the IRQ relative to a valid trigger, register all
IRQs in a disabled state in the device open path.  This allows mask
operations on the IRQ to nest within the overall enable state governed
by a valid eventfd signal.  This decouples @masked, protected by the
@locked spinlock from @trigger, protected via the @igate mutex.

In doing so, it's guaranteed that changes to @trigger cannot race the
IRQ handlers because the IRQ handler is synchronously disabled before
modifying the trigger, and loopback triggering of the IRQ via ioctl is
safe due to serialization with trigger changes via igate.

For compatibility, request_irq() failures are maintained to be local to
the SET_IRQS ioctl rather than a fatal error in the open device path.
This allows, for example, a userspace driver with polling mode support
to continue to work regardless of moving the request_irq() call site.
This necessarily blocks all SET_IRQS access to the failed index.

Cc: Eric Auger &lt;eric.auger@redhat.com&gt;
Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 57f972e2b341 ("vfio/platform: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-7-alex.williamson@redhat.com
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: Disable virqfds on cleanup</title>
<updated>2024-04-03T13:32:19+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b565c2fd3831935674089ae6f5bf2c39a56bf99d'/>
<id>b565c2fd3831935674089ae6f5bf2c39a56bf99d</id>
<content type='text'>
[ Upstream commit fcdc0d3d40bc26c105acf8467f7d9018970944ae ]

irqfds for mask and unmask that are not specifically disabled by the
user are leaked.  Remove any irqfds during cleanup

Cc: Eric Auger &lt;eric.auger@redhat.com&gt;
Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: a7fa7c77cf15 ("vfio/platform: implement IRQ masking/unmasking via an eventfd")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-6-alex.williamson@redhat.com
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 fcdc0d3d40bc26c105acf8467f7d9018970944ae ]

irqfds for mask and unmask that are not specifically disabled by the
user are leaked.  Remove any irqfds during cleanup

Cc: Eric Auger &lt;eric.auger@redhat.com&gt;
Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: a7fa7c77cf15 ("vfio/platform: implement IRQ masking/unmasking via an eventfd")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-6-alex.williamson@redhat.com
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: Lock external INTx masking ops</title>
<updated>2024-04-03T13:32:19+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=03505e3344b0576fd619416793a31eae9c5b73bf'/>
<id>03505e3344b0576fd619416793a31eae9c5b73bf</id>
<content type='text'>
[ Upstream commit 810cd4bb53456d0503cc4e7934e063835152c1b7 ]

Mask operations through config space changes to DisINTx may race INTx
configuration changes via ioctl.  Create wrappers that add locking for
paths outside of the core interrupt code.

In particular, irq_type is updated holding igate, therefore testing
is_intx() requires holding igate.  For example clearing DisINTx from
config space can otherwise race changes of the interrupt configuration.

This aligns interfaces which may trigger the INTx eventfd into two
camps, one side serialized by igate and the other only enabled while
INTx is configured.  A subsequent patch introduces synchronization for
the latter flows.

Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-3-alex.williamson@redhat.com
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 810cd4bb53456d0503cc4e7934e063835152c1b7 ]

Mask operations through config space changes to DisINTx may race INTx
configuration changes via ioctl.  Create wrappers that add locking for
paths outside of the core interrupt code.

In particular, irq_type is updated holding igate, therefore testing
is_intx() requires holding igate.  For example clearing DisINTx from
config space can otherwise race changes of the interrupt configuration.

This aligns interfaces which may trigger the INTx eventfd into two
camps, one side serialized by igate and the other only enabled while
INTx is configured.  A subsequent patch introduces synchronization for
the latter flows.

Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Reinette Chatre &lt;reinette.chatre@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-3-alex.williamson@redhat.com
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: Disable auto-enable of exclusive INTx IRQ</title>
<updated>2024-04-03T13:32:19+00:00</updated>
<author>
<name>Alex Williamson</name>
<email>alex.williamson@redhat.com</email>
</author>
<published>2024-03-08T23:05:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf0bc84a20e6109ab07d5dc072067bd01eb931ec'/>
<id>bf0bc84a20e6109ab07d5dc072067bd01eb931ec</id>
<content type='text'>
[ Upstream commit fe9a7082684eb059b925c535682e68c34d487d43 ]

Currently for devices requiring masking at the irqchip for INTx, ie.
devices without DisINTx support, the IRQ is enabled in request_irq()
and subsequently disabled as necessary to align with the masked status
flag.  This presents a window where the interrupt could fire between
these events, resulting in the IRQ incrementing the disable depth twice.
This would be unrecoverable for a user since the masked flag prevents
nested enables through vfio.

Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx
is never auto-enabled, then unmask as required.

Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-2-alex.williamson@redhat.com
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 fe9a7082684eb059b925c535682e68c34d487d43 ]

Currently for devices requiring masking at the irqchip for INTx, ie.
devices without DisINTx support, the IRQ is enabled in request_irq()
and subsequently disabled as necessary to align with the masked status
flag.  This presents a window where the interrupt could fire between
these events, resulting in the IRQ incrementing the disable depth twice.
This would be unrecoverable for a user since the masked flag prevents
nested enables through vfio.

Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx
is never auto-enabled, then unmask as required.

Cc:  &lt;stable@vger.kernel.org&gt;
Fixes: 89e1f7d4c66d ("vfio: Add PCI device driver")
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Reviewed-by: Eric Auger &lt;eric.auger@redhat.com&gt;
Link: https://lore.kernel.org/r/20240308230557.805580-2-alex.williamson@redhat.com
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/pds: Always clear the save/restore FDs on reset</title>
<updated>2024-04-03T13:32:09+00:00</updated>
<author>
<name>Brett Creeley</name>
<email>brett.creeley@amd.com</email>
</author>
<published>2024-02-28T00:32:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6c917ae4d3107e03cc1778632ed4d46d5813fdc5'/>
<id>6c917ae4d3107e03cc1778632ed4d46d5813fdc5</id>
<content type='text'>
[ Upstream commit 8512ed256334f6637fc0699ce794792c357544ec ]

After reset the VFIO device state will always be put in
VFIO_DEVICE_STATE_RUNNING, but the save/restore files will only be
cleared if the previous state was VFIO_DEVICE_STATE_ERROR. This
can/will cause the restore/save files to be leaked if/when the
migration state machine transitions through the states that
re-allocates these files. Fix this by always clearing the
restore/save files for resets.

Fixes: 7dabb1bcd177 ("vfio/pds: Add support for firmware recovery")
Cc: stable@vger.kernel.org
Signed-off-by: Brett Creeley &lt;brett.creeley@amd.com&gt;
Reviewed-by: Shannon Nelson &lt;shannon.nelson@amd.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Link: https://lore.kernel.org/r/20240228003205.47311-2-brett.creeley@amd.com
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 8512ed256334f6637fc0699ce794792c357544ec ]

After reset the VFIO device state will always be put in
VFIO_DEVICE_STATE_RUNNING, but the save/restore files will only be
cleared if the previous state was VFIO_DEVICE_STATE_ERROR. This
can/will cause the restore/save files to be leaked if/when the
migration state machine transitions through the states that
re-allocates these files. Fix this by always clearing the
restore/save files for resets.

Fixes: 7dabb1bcd177 ("vfio/pds: Add support for firmware recovery")
Cc: stable@vger.kernel.org
Signed-off-by: Brett Creeley &lt;brett.creeley@amd.com&gt;
Reviewed-by: Shannon Nelson &lt;shannon.nelson@amd.com&gt;
Reviewed-by: Kevin Tian &lt;kevin.tian@intel.com&gt;
Link: https://lore.kernel.org/r/20240228003205.47311-2-brett.creeley@amd.com
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>Merge tag 'vfio-v6.8-rc1' of https://github.com/awilliam/linux-vfio</title>
<updated>2024-01-18T23:57:25+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-01-18T23:57:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=244aefb1c64ad562b48929e6d85e07bc79e331d6'/>
<id>244aefb1c64ad562b48929e6d85e07bc79e331d6</id>
<content type='text'>
Pull VFIO updates from Alex Williamson:

 - Add debugfs support, initially used for reporting device migration
   state (Longfang Liu)

 - Fixes and support for migration dirty tracking across multiple IOVA
   regions in the pds-vfio-pci driver (Brett Creeley)

 - Improved IOMMU allocation accounting visibility (Pasha Tatashin)

 - Virtio infrastructure and a new virtio-vfio-pci variant driver, which
   provides emulation of a legacy virtio interfaces on modern virtio
   hardware for virtio-net VF devices where the PF driver exposes
   support for legacy admin queues, ie. an emulated IO BAR on an SR-IOV
   VF to provide driver ABI compatibility to legacy devices (Yishai
   Hadas &amp; Feng Liu)

 - Migration fixes for the hisi-acc-vfio-pci variant driver (Shameer
   Kolothum)

 - Kconfig dependency fix for new virtio-vfio-pci variant driver (Arnd
   Bergmann)

* tag 'vfio-v6.8-rc1' of https://github.com/awilliam/linux-vfio: (22 commits)
  vfio/virtio: fix virtio-pci dependency
  hisi_acc_vfio_pci: Update migration data pointer correctly on saving/resume
  vfio/virtio: Declare virtiovf_pci_aer_reset_done() static
  vfio/virtio: Introduce a vfio driver over virtio devices
  vfio/pci: Expose vfio_pci_core_iowrite/read##size()
  vfio/pci: Expose vfio_pci_core_setup_barmap()
  virtio-pci: Introduce APIs to execute legacy IO admin commands
  virtio-pci: Initialize the supported admin commands
  virtio-pci: Introduce admin commands
  virtio-pci: Introduce admin command sending function
  virtio-pci: Introduce admin virtqueue
  virtio: Define feature bit for administration virtqueue
  vfio/type1: account iommu allocations
  vfio/pds: Add multi-region support
  vfio/pds: Move seq/ack bitmaps into region struct
  vfio/pds: Pass region info to relevant functions
  vfio/pds: Move and rename region specific info
  vfio/pds: Only use a single SGL for both seq and ack
  vfio/pds: Fix calculations in pds_vfio_dirty_sync
  MAINTAINERS: Add vfio debugfs interface doc link
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull VFIO updates from Alex Williamson:

 - Add debugfs support, initially used for reporting device migration
   state (Longfang Liu)

 - Fixes and support for migration dirty tracking across multiple IOVA
   regions in the pds-vfio-pci driver (Brett Creeley)

 - Improved IOMMU allocation accounting visibility (Pasha Tatashin)

 - Virtio infrastructure and a new virtio-vfio-pci variant driver, which
   provides emulation of a legacy virtio interfaces on modern virtio
   hardware for virtio-net VF devices where the PF driver exposes
   support for legacy admin queues, ie. an emulated IO BAR on an SR-IOV
   VF to provide driver ABI compatibility to legacy devices (Yishai
   Hadas &amp; Feng Liu)

 - Migration fixes for the hisi-acc-vfio-pci variant driver (Shameer
   Kolothum)

 - Kconfig dependency fix for new virtio-vfio-pci variant driver (Arnd
   Bergmann)

* tag 'vfio-v6.8-rc1' of https://github.com/awilliam/linux-vfio: (22 commits)
  vfio/virtio: fix virtio-pci dependency
  hisi_acc_vfio_pci: Update migration data pointer correctly on saving/resume
  vfio/virtio: Declare virtiovf_pci_aer_reset_done() static
  vfio/virtio: Introduce a vfio driver over virtio devices
  vfio/pci: Expose vfio_pci_core_iowrite/read##size()
  vfio/pci: Expose vfio_pci_core_setup_barmap()
  virtio-pci: Introduce APIs to execute legacy IO admin commands
  virtio-pci: Initialize the supported admin commands
  virtio-pci: Introduce admin commands
  virtio-pci: Introduce admin command sending function
  virtio-pci: Introduce admin virtqueue
  virtio: Define feature bit for administration virtqueue
  vfio/type1: account iommu allocations
  vfio/pds: Add multi-region support
  vfio/pds: Move seq/ack bitmaps into region struct
  vfio/pds: Pass region info to relevant functions
  vfio/pds: Move and rename region specific info
  vfio/pds: Only use a single SGL for both seq and ack
  vfio/pds: Fix calculations in pds_vfio_dirty_sync
  MAINTAINERS: Add vfio debugfs interface doc link
  ...
</pre>
</div>
</content>
</entry>
</feed>
