<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/linux, branch v6.4</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'perf_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2023-06-25T17:13:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-25T17:13:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=547cc9be86f4c51c51fd429ace6c2e1ef9050d15'/>
<id>547cc9be86f4c51c51fd429ace6c2e1ef9050d15</id>
<content type='text'>
Pull perf fixes from Borislav Petkov:

 - Drop the __weak attribute from a function prototype as it otherwise
   leads to the function getting replaced by a dummy stub

 - Fix the umask value setup of the frontend event as former is
   different on two Intel cores

* tag 'perf_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix the FRONTEND encoding on GNR and MTL
  perf/core: Drop __weak attribute from arch_perf_update_userpage() prototype
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf fixes from Borislav Petkov:

 - Drop the __weak attribute from a function prototype as it otherwise
   leads to the function getting replaced by a dummy stub

 - Fix the umask value setup of the frontend event as former is
   different on two Intel cores

* tag 'perf_urgent_for_v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix the FRONTEND encoding on GNR and MTL
  perf/core: Drop __weak attribute from arch_perf_update_userpage() prototype
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'gpio-fixes-for-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux</title>
<updated>2023-06-23T22:24:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-23T22:24:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6edecb9986eeffbf67e89aa510bc07835067cf60'/>
<id>6edecb9986eeffbf67e89aa510bc07835067cf60</id>
<content type='text'>
Pull gpio fixes from Bartosz Golaszewski:

 - fix IRQ initialization in gpiochip_irqchip_add_domain()

 - add a missing return value check for platform_get_irq() in
   gpio-sifive

 - don't free irq_domains which GPIOLIB does not manage

* tag 'gpio-fixes-for-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpiolib: Fix irq_domain resource tracking for gpiochip_irqchip_add_domain()
  gpio: sifive: add missing check for platform_get_irq
  gpiolib: Fix GPIO chip IRQ initialization restriction
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull gpio fixes from Bartosz Golaszewski:

 - fix IRQ initialization in gpiochip_irqchip_add_domain()

 - add a missing return value check for platform_get_irq() in
   gpio-sifive

 - don't free irq_domains which GPIOLIB does not manage

* tag 'gpio-fixes-for-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpiolib: Fix irq_domain resource tracking for gpiochip_irqchip_add_domain()
  gpio: sifive: add missing check for platform_get_irq
  gpiolib: Fix GPIO chip IRQ initialization restriction
</pre>
</div>
</content>
</entry>
<entry>
<title>workqueue: clean up WORK_* constant types, clarify masking</title>
<updated>2023-06-23T19:08:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-23T19:08:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=afa4bb778e48d79e4a642ed41e3b4e0de7489a6c'/>
<id>afa4bb778e48d79e4a642ed41e3b4e0de7489a6c</id>
<content type='text'>
Dave Airlie reports that gcc-13.1.1 has started complaining about some
of the workqueue code in 32-bit arm builds:

  kernel/workqueue.c: In function ‘get_work_pwq’:
  kernel/workqueue.c:713:24: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
    713 |                 return (void *)(data &amp; WORK_STRUCT_WQ_DATA_MASK);
        |                        ^
  [ ... a couple of other cases ... ]

and while it's not immediately clear exactly why gcc started complaining
about it now, I suspect it's some C23-induced enum type handlign fixup in
gcc-13 is the cause.

Whatever the reason for starting to complain, the code and data types
are indeed disgusting enough that the complaint is warranted.

The wq code ends up creating various "helper constants" (like that
WORK_STRUCT_WQ_DATA_MASK) using an enum type, which is all kinds of
confused.  The mask needs to be 'unsigned long', not some unspecified
enum type.

To make matters worse, the actual "mask and cast to a pointer" is
repeated a couple of times, and the cast isn't even always done to the
right pointer, but - as the error case above - to a 'void *' with then
the compiler finishing the job.

That's now how we roll in the kernel.

So create the masks using the proper types rather than some ambiguous
enumeration, and use a nice helper that actually does the type
conversion in one well-defined place.

Incidentally, this magically makes clang generate better code.  That,
admittedly, is really just a sign of clang having been seriously
confused before, and cleaning up the typing unconfuses the compiler too.

Reported-by: Dave Airlie &lt;airlied@gmail.com&gt;
Link: https://lore.kernel.org/lkml/CAPM=9twNnV4zMCvrPkw3H-ajZOH-01JVh_kDrxdPYQErz8ZTdA@mail.gmail.com/
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Dave Airlie reports that gcc-13.1.1 has started complaining about some
of the workqueue code in 32-bit arm builds:

  kernel/workqueue.c: In function ‘get_work_pwq’:
  kernel/workqueue.c:713:24: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
    713 |                 return (void *)(data &amp; WORK_STRUCT_WQ_DATA_MASK);
        |                        ^
  [ ... a couple of other cases ... ]

and while it's not immediately clear exactly why gcc started complaining
about it now, I suspect it's some C23-induced enum type handlign fixup in
gcc-13 is the cause.

Whatever the reason for starting to complain, the code and data types
are indeed disgusting enough that the complaint is warranted.

The wq code ends up creating various "helper constants" (like that
WORK_STRUCT_WQ_DATA_MASK) using an enum type, which is all kinds of
confused.  The mask needs to be 'unsigned long', not some unspecified
enum type.

To make matters worse, the actual "mask and cast to a pointer" is
repeated a couple of times, and the cast isn't even always done to the
right pointer, but - as the error case above - to a 'void *' with then
the compiler finishing the job.

That's now how we roll in the kernel.

So create the masks using the proper types rather than some ambiguous
enumeration, and use a nice helper that actually does the type
conversion in one well-defined place.

Incidentally, this magically makes clang generate better code.  That,
admittedly, is really just a sign of clang having been seriously
confused before, and cleaning up the typing unconfuses the compiler too.

Reported-by: Dave Airlie &lt;airlied@gmail.com&gt;
Link: https://lore.kernel.org/lkml/CAPM=9twNnV4zMCvrPkw3H-ajZOH-01JVh_kDrxdPYQErz8ZTdA@mail.gmail.com/
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Tejun Heo &lt;tj@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'regulator-fix-v6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator</title>
<updated>2023-06-21T17:29:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-21T17:29:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6e6fb54de1ef34fd20a0bdd99ce72a657814391b'/>
<id>6e6fb54de1ef34fd20a0bdd99ce72a657814391b</id>
<content type='text'>
Pull regulator fix from Mark Brown:
 "One simple fix for v6.4, some incorrectly specified bitfield masks in
  the PCA9450 driver"

* tag 'regulator-fix-v6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: pca9450: Fix LDO3OUT and LDO4OUT MASK
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull regulator fix from Mark Brown:
 "One simple fix for v6.4, some incorrectly specified bitfield masks in
  the PCA9450 driver"

* tag 'regulator-fix-v6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: pca9450: Fix LDO3OUT and LDO4OUT MASK
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux</title>
<updated>2023-06-20T00:05:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-20T00:05:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=692b7dc87ca6d55ab254f8259e6f970171dc9d01'/>
<id>692b7dc87ca6d55ab254f8259e6f970171dc9d01</id>
<content type='text'>
Pull hyperv fixes from Wei Liu:

 - Fix races in Hyper-V PCI controller (Dexuan Cui)

 - Fix handling of hyperv_pcpu_input_arg (Michael Kelley)

 - Fix vmbus_wait_for_unload to scan present CPUs (Michael Kelley)

 - Call hv_synic_free in the failure path of hv_synic_alloc (Dexuan Cui)

 - Add noop for real mode handlers for virtual trust level code (Saurabh
   Sengar)

* tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  PCI: hv: Add a per-bus mutex state_lock
  Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally"
  PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev
  PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic
  PCI: hv: Fix a race condition bug in hv_pci_query_relations()
  arm64/hyperv: Use CPUHP_AP_HYPERV_ONLINE state to fix CPU online sequencing
  x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline
  Drivers: hv: vmbus: Fix vmbus_wait_for_unload() to scan present CPUs
  Drivers: hv: vmbus: Call hv_synic_free() if hv_synic_alloc() fails
  x86/hyperv/vtl: Add noop for realmode pointers
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull hyperv fixes from Wei Liu:

 - Fix races in Hyper-V PCI controller (Dexuan Cui)

 - Fix handling of hyperv_pcpu_input_arg (Michael Kelley)

 - Fix vmbus_wait_for_unload to scan present CPUs (Michael Kelley)

 - Call hv_synic_free in the failure path of hv_synic_alloc (Dexuan Cui)

 - Add noop for real mode handlers for virtual trust level code (Saurabh
   Sengar)

* tag 'hyperv-fixes-signed-20230619' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  PCI: hv: Add a per-bus mutex state_lock
  Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally"
  PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev
  PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic
  PCI: hv: Fix a race condition bug in hv_pci_query_relations()
  arm64/hyperv: Use CPUHP_AP_HYPERV_ONLINE state to fix CPU online sequencing
  x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline
  Drivers: hv: vmbus: Fix vmbus_wait_for_unload() to scan present CPUs
  Drivers: hv: vmbus: Call hv_synic_free() if hv_synic_alloc() fails
  x86/hyperv/vtl: Add noop for realmode pointers
</pre>
</div>
</content>
</entry>
<entry>
<title>regulator: pca9450: Fix LDO3OUT and LDO4OUT MASK</title>
<updated>2023-06-19T14:13:17+00:00</updated>
<author>
<name>Teresa Remmet</name>
<email>t.remmet@phytec.de</email>
</author>
<published>2023-06-14T12:52:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7257d930aadcd62d1c7971ab14f3b1126356abdc'/>
<id>7257d930aadcd62d1c7971ab14f3b1126356abdc</id>
<content type='text'>
L3_OUT and L4_OUT Bit fields range from Bit 0:4 and thus the
mask should be 0x1F instead of 0x0F.

Fixes: 0935ff5f1f0a ("regulator: pca9450: add pca9450 pmic driver")
Signed-off-by: Teresa Remmet &lt;t.remmet@phytec.de&gt;
Reviewed-by: Frieder Schrempf &lt;frieder.schrempf@kontron.de&gt;
Link: https://lore.kernel.org/r/20230614125240.3946519-1-t.remmet@phytec.de
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
L3_OUT and L4_OUT Bit fields range from Bit 0:4 and thus the
mask should be 0x1F instead of 0x0F.

Fixes: 0935ff5f1f0a ("regulator: pca9450: add pca9450 pmic driver")
Signed-off-by: Teresa Remmet &lt;t.remmet@phytec.de&gt;
Reviewed-by: Frieder Schrempf &lt;frieder.schrempf@kontron.de&gt;
Link: https://lore.kernel.org/r/20230614125240.3946519-1-t.remmet@phytec.de
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>gpiolib: Fix irq_domain resource tracking for gpiochip_irqchip_add_domain()</title>
<updated>2023-06-19T12:57:38+00:00</updated>
<author>
<name>Michael Walle</name>
<email>mwalle@kernel.org</email>
</author>
<published>2023-06-19T08:56:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ff7a1790fbf92f1bdd0966d3f0da3ea808ede876'/>
<id>ff7a1790fbf92f1bdd0966d3f0da3ea808ede876</id>
<content type='text'>
Up until commit 6a45b0e2589f ("gpiolib: Introduce
gpiochip_irqchip_add_domain()") all irq_domains were allocated
by gpiolib itself and thus gpiolib also takes care of freeing it.

With gpiochip_irqchip_add_domain() a user of gpiolib can associate an
irq_domain with the gpio_chip. This irq_domain is not managed by
gpiolib and therefore must not be freed by gpiolib.

Fixes: 6a45b0e2589f ("gpiolib: Introduce gpiochip_irqchip_add_domain()")
Reported-by: Jiawen Wu &lt;jiawenwu@trustnetic.com&gt;
Signed-off-by: Michael Walle &lt;mwalle@kernel.org&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Reviewed-by: Andy Shevchenko &lt;andy@kernel.org&gt;
Signed-off-by: Bartosz Golaszewski &lt;bartosz.golaszewski@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Up until commit 6a45b0e2589f ("gpiolib: Introduce
gpiochip_irqchip_add_domain()") all irq_domains were allocated
by gpiolib itself and thus gpiolib also takes care of freeing it.

With gpiochip_irqchip_add_domain() a user of gpiolib can associate an
irq_domain with the gpio_chip. This irq_domain is not managed by
gpiolib and therefore must not be freed by gpiolib.

Fixes: 6a45b0e2589f ("gpiolib: Introduce gpiochip_irqchip_add_domain()")
Reported-by: Jiawen Wu &lt;jiawenwu@trustnetic.com&gt;
Signed-off-by: Michael Walle &lt;mwalle@kernel.org&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Reviewed-by: Andy Shevchenko &lt;andy@kernel.org&gt;
Signed-off-by: Bartosz Golaszewski &lt;bartosz.golaszewski@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'ata-6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata</title>
<updated>2023-06-18T16:48:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-18T16:48:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ecbcffe3b7edc9a42b4e29ed8dafd56855ee675c'/>
<id>ecbcffe3b7edc9a42b4e29ed8dafd56855ee675c</id>
<content type='text'>
Pull ata fix from Damien Le Moal:

 - Avoid deadlocks on resume from sleep by delaying scsi rescan until
   the scsi device is also fully resumed.

* tag 'ata-6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: libata-scsi: Avoid deadlock on rescan after device resume
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ata fix from Damien Le Moal:

 - Avoid deadlocks on resume from sleep by delaying scsi rescan until
   the scsi device is also fully resumed.

* tag 'ata-6.4-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: libata-scsi: Avoid deadlock on rescan after device resume
</pre>
</div>
</content>
</entry>
<entry>
<title>ata: libata-scsi: Avoid deadlock on rescan after device resume</title>
<updated>2023-06-18T03:00:49+00:00</updated>
<author>
<name>Damien Le Moal</name>
<email>dlemoal@kernel.org</email>
</author>
<published>2023-06-15T08:18:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6aa0365a3c8512587fffd42fe438768709ddef8e'/>
<id>6aa0365a3c8512587fffd42fe438768709ddef8e</id>
<content type='text'>
When an ATA port is resumed from sleep, the port is reset and a power
management request issued to libata EH to reset the port and rescanning
the device(s) attached to the port. Device rescanning is done by
scheduling an ata_scsi_dev_rescan() work, which will execute
scsi_rescan_device().

However, scsi_rescan_device() takes the generic device lock, which is
also taken by dpm_resume() when the SCSI device is resumed as well. If
a device rescan execution starts before the completion of the SCSI
device resume, the rcu locking used to refresh the cached VPD pages of
the device, combined with the generic device locking from
scsi_rescan_device() and from dpm_resume() can cause a deadlock.

Avoid this situation by changing struct ata_port scsi_rescan_task to be
a delayed work instead of a simple work_struct. ata_scsi_dev_rescan() is
modified to check if the SCSI device associated with the ATA device that
must be rescanned is not suspended. If the SCSI device is still
suspended, ata_scsi_dev_rescan() returns early and reschedule itself for
execution after an arbitrary delay of 5ms.

Reported-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Reported-by: Joe Breuer &lt;linux-kernel@jmbreuer.net&gt;
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217530
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Tested-by: Joe Breuer &lt;linux-kernel@jmbreuer.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When an ATA port is resumed from sleep, the port is reset and a power
management request issued to libata EH to reset the port and rescanning
the device(s) attached to the port. Device rescanning is done by
scheduling an ata_scsi_dev_rescan() work, which will execute
scsi_rescan_device().

However, scsi_rescan_device() takes the generic device lock, which is
also taken by dpm_resume() when the SCSI device is resumed as well. If
a device rescan execution starts before the completion of the SCSI
device resume, the rcu locking used to refresh the cached VPD pages of
the device, combined with the generic device locking from
scsi_rescan_device() and from dpm_resume() can cause a deadlock.

Avoid this situation by changing struct ata_port scsi_rescan_task to be
a delayed work instead of a simple work_struct. ata_scsi_dev_rescan() is
modified to check if the SCSI device associated with the ATA device that
must be rescanned is not suspended. If the SCSI device is still
suspended, ata_scsi_dev_rescan() returns early and reschedule itself for
execution after an arbitrary delay of 5ms.

Reported-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Reported-by: Joe Breuer &lt;linux-kernel@jmbreuer.net&gt;
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217530
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Signed-off-by: Damien Le Moal &lt;dlemoal@kernel.org&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Tested-by: Joe Breuer &lt;linux-kernel@jmbreuer.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/hyperv: Fix hyperv_pcpu_input_arg handling when CPUs go online/offline</title>
<updated>2023-06-17T23:09:47+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mikelley@microsoft.com</email>
</author>
<published>2023-05-23T17:14:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9636be85cc5bdd8b7a7f6a53405cbcc52161c93c'/>
<id>9636be85cc5bdd8b7a7f6a53405cbcc52161c93c</id>
<content type='text'>
These commits

a494aef23dfc ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg")
2c6ba4216844 ("PCI: hv: Enable PCI pass-thru devices in Confidential VMs")

update the Hyper-V virtual PCI driver to use the hyperv_pcpu_input_arg
because that memory will be correctly marked as decrypted or encrypted
for all VM types (CoCo or normal). But problems ensue when CPUs in the
VM go online or offline after virtual PCI devices have been configured.

When a CPU is brought online, the hyperv_pcpu_input_arg for that CPU is
initialized by hv_cpu_init() running under state CPUHP_AP_ONLINE_DYN.
But this state occurs after state CPUHP_AP_IRQ_AFFINITY_ONLINE, which
may call the virtual PCI driver and fault trying to use the as yet
uninitialized hyperv_pcpu_input_arg. A similar problem occurs in a CoCo
VM if the MMIO read and write hypercalls are used from state
CPUHP_AP_IRQ_AFFINITY_ONLINE.

When a CPU is taken offline, IRQs may be reassigned in state
CPUHP_TEARDOWN_CPU. Again, the virtual PCI driver may fault trying to
use the hyperv_pcpu_input_arg that has already been freed by a
higher state.

Fix the onlining problem by adding state CPUHP_AP_HYPERV_ONLINE
immediately after CPUHP_AP_ONLINE_IDLE (similar to CPUHP_AP_KVM_ONLINE)
and before CPUHP_AP_IRQ_AFFINITY_ONLINE. Use this new state for
Hyper-V initialization so that hyperv_pcpu_input_arg is allocated
early enough.

Fix the offlining problem by not freeing hyperv_pcpu_input_arg when
a CPU goes offline. Retain the allocated memory, and reuse it if
the CPU comes back online later.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Acked-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Link: https://lore.kernel.org/r/1684862062-51576-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
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<pre>
These commits

a494aef23dfc ("PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg")
2c6ba4216844 ("PCI: hv: Enable PCI pass-thru devices in Confidential VMs")

update the Hyper-V virtual PCI driver to use the hyperv_pcpu_input_arg
because that memory will be correctly marked as decrypted or encrypted
for all VM types (CoCo or normal). But problems ensue when CPUs in the
VM go online or offline after virtual PCI devices have been configured.

When a CPU is brought online, the hyperv_pcpu_input_arg for that CPU is
initialized by hv_cpu_init() running under state CPUHP_AP_ONLINE_DYN.
But this state occurs after state CPUHP_AP_IRQ_AFFINITY_ONLINE, which
may call the virtual PCI driver and fault trying to use the as yet
uninitialized hyperv_pcpu_input_arg. A similar problem occurs in a CoCo
VM if the MMIO read and write hypercalls are used from state
CPUHP_AP_IRQ_AFFINITY_ONLINE.

When a CPU is taken offline, IRQs may be reassigned in state
CPUHP_TEARDOWN_CPU. Again, the virtual PCI driver may fault trying to
use the hyperv_pcpu_input_arg that has already been freed by a
higher state.

Fix the onlining problem by adding state CPUHP_AP_HYPERV_ONLINE
immediately after CPUHP_AP_ONLINE_IDLE (similar to CPUHP_AP_KVM_ONLINE)
and before CPUHP_AP_IRQ_AFFINITY_ONLINE. Use this new state for
Hyper-V initialization so that hyperv_pcpu_input_arg is allocated
early enough.

Fix the offlining problem by not freeing hyperv_pcpu_input_arg when
a CPU goes offline. Retain the allocated memory, and reuse it if
the CPU comes back online later.

Signed-off-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Reviewed-by: Vitaly Kuznetsov &lt;vkuznets@redhat.com&gt;
Acked-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Reviewed-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Link: https://lore.kernel.org/r/1684862062-51576-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
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