<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/pci, branch v6.4.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>PCI/ACPI: Call _REG when transitioning D-states</title>
<updated>2023-07-05T17:30:30+00:00</updated>
<author>
<name>Mario Limonciello</name>
<email>mario.limonciello@amd.com</email>
</author>
<published>2023-06-20T14:04:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dfb27a7668963317ef6a2bfb89d5ebd270e9259e'/>
<id>dfb27a7668963317ef6a2bfb89d5ebd270e9259e</id>
<content type='text'>
commit 112a7f9c8edbf76f7cb83856a6cb6b60a210b659 upstream.

ACPI r6.5, sec 6.5.4, describes how AML is unable to access an
OperationRegion unless _REG has been called to connect a handler:

  The OS runs _REG control methods to inform AML code of a change in the
  availability of an operation region. When an operation region handler is
  unavailable, AML cannot access data fields in that region.  (Operation
  region writes will be ignored and reads will return indeterminate data.)

The PCI core does not call _REG at any time, leading to the undefined
behavior mentioned in the spec.

The spec explains that _REG should be executed to indicate whether a
given region can be accessed:

  Once _REG has been executed for a particular operation region, indicating
  that the operation region handler is ready, a control method can access
  fields in the operation region. Conversely, control methods must not
  access fields in operation regions when _REG method execution has not
  indicated that the operation region handler is ready.

An example included in the spec demonstrates calling _REG when devices are
turned off: "when the host controller or bridge controller is turned off
or disabled, PCI Config Space Operation Regions for child devices are
no longer available. As such, ETH0’s _REG method will be run when it
is turned off and will again be run when PCI1 is turned off."

It is reported that ASMedia PCIe GPIO controllers fail functional tests
after the system has returning from suspend (S3 or s2idle). This is because
the BIOS checks whether the OSPM has called the _REG method to determine
whether it can interact with the OperationRegion assigned to the device as
part of the other AML called for the device.

To fix this issue, call acpi_evaluate_reg() when devices are transitioning
to D3cold or D0.

[bhelgaas: split pci_power_t checking to preliminary patch]
Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#reg-region
Link: https://lore.kernel.org/r/20230620140451.21007-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 112a7f9c8edbf76f7cb83856a6cb6b60a210b659 upstream.

ACPI r6.5, sec 6.5.4, describes how AML is unable to access an
OperationRegion unless _REG has been called to connect a handler:

  The OS runs _REG control methods to inform AML code of a change in the
  availability of an operation region. When an operation region handler is
  unavailable, AML cannot access data fields in that region.  (Operation
  region writes will be ignored and reads will return indeterminate data.)

The PCI core does not call _REG at any time, leading to the undefined
behavior mentioned in the spec.

The spec explains that _REG should be executed to indicate whether a
given region can be accessed:

  Once _REG has been executed for a particular operation region, indicating
  that the operation region handler is ready, a control method can access
  fields in the operation region. Conversely, control methods must not
  access fields in operation regions when _REG method execution has not
  indicated that the operation region handler is ready.

An example included in the spec demonstrates calling _REG when devices are
turned off: "when the host controller or bridge controller is turned off
or disabled, PCI Config Space Operation Regions for child devices are
no longer available. As such, ETH0’s _REG method will be run when it
is turned off and will again be run when PCI1 is turned off."

It is reported that ASMedia PCIe GPIO controllers fail functional tests
after the system has returning from suspend (S3 or s2idle). This is because
the BIOS checks whether the OSPM has called the _REG method to determine
whether it can interact with the OperationRegion assigned to the device as
part of the other AML called for the device.

To fix this issue, call acpi_evaluate_reg() when devices are transitioning
to D3cold or D0.

[bhelgaas: split pci_power_t checking to preliminary patch]
Link: https://uefi.org/specs/ACPI/6.5/06_Device_Configuration.html#reg-region
Link: https://lore.kernel.org/r/20230620140451.21007-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Rafael J. Wysocki &lt;rafael@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/ACPI: Validate acpi_pci_set_power_state() parameter</title>
<updated>2023-07-05T17:30:30+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2023-06-21T21:36:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f933605c176731a89ef0da8229894e7547c358d6'/>
<id>f933605c176731a89ef0da8229894e7547c358d6</id>
<content type='text'>
commit 5557b62634abbd55bab7b154ce4bca348ad7f96f upstream.

Previously acpi_pci_set_power_state() assumed the requested power state was
valid (PCI_D0 ... PCI_D3cold).  If a caller supplied something else, we
could index outside the state_conv[] array and pass junk to
acpi_device_set_power().

Validate the pci_power_t parameter and return -EINVAL if it's invalid.

Link: https://lore.kernel.org/r/20230621222857.GA122930@bhelgaas
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5557b62634abbd55bab7b154ce4bca348ad7f96f upstream.

Previously acpi_pci_set_power_state() assumed the requested power state was
valid (PCI_D0 ... PCI_D3cold).  If a caller supplied something else, we
could index outside the state_conv[] array and pass junk to
acpi_device_set_power().

Validate the pci_power_t parameter and return -EINVAL if it's invalid.

Link: https://lore.kernel.org/r/20230621222857.GA122930@bhelgaas
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</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-stable.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>PCI: hv: Add a per-bus mutex state_lock</title>
<updated>2023-06-18T03:05:40+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-06-15T04:44:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=067d6ec7ed5b49380688e06c1e5f883a71bef4fe'/>
<id>067d6ec7ed5b49380688e06c1e5f883a71bef4fe</id>
<content type='text'>
In the case of fast device addition/removal, it's possible that
hv_eject_device_work() can start to run before create_root_hv_pci_bus()
starts to run; as a result, the pci_get_domain_bus_and_slot() in
hv_eject_device_work() can return a 'pdev' of NULL, and
hv_eject_device_work() can remove the 'hpdev', and immediately send a
message PCI_EJECTION_COMPLETE to the host, and the host immediately
unassigns the PCI device from the guest; meanwhile,
create_root_hv_pci_bus() and the PCI device driver can be probing the
dead PCI device and reporting timeout errors.

Fix the issue by adding a per-bus mutex 'state_lock' and grabbing the
mutex before powering on the PCI bus in hv_pci_enter_d0(): when
hv_eject_device_work() starts to run, it's able to find the 'pdev' and call
pci_stop_and_remove_bus_device(pdev): if the PCI device driver has
loaded, the PCI device driver's probe() function is already called in
create_root_hv_pci_bus() -&gt; pci_bus_add_devices(), and now
hv_eject_device_work() -&gt; pci_stop_and_remove_bus_device() is able
to call the PCI device driver's remove() function and remove the device
reliably; if the PCI device driver hasn't loaded yet, the function call
hv_eject_device_work() -&gt; pci_stop_and_remove_bus_device() is able to
remove the PCI device reliably and the PCI device driver's probe()
function won't be called; if the PCI device driver's probe() is already
running (e.g., systemd-udev is loading the PCI device driver), it must
be holding the per-device lock, and after the probe() finishes and releases
the lock, hv_eject_device_work() -&gt; pci_stop_and_remove_bus_device() is
able to proceed to remove the device reliably.

Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Lorenzo Pieralisi &lt;lpieralisi@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-6-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In the case of fast device addition/removal, it's possible that
hv_eject_device_work() can start to run before create_root_hv_pci_bus()
starts to run; as a result, the pci_get_domain_bus_and_slot() in
hv_eject_device_work() can return a 'pdev' of NULL, and
hv_eject_device_work() can remove the 'hpdev', and immediately send a
message PCI_EJECTION_COMPLETE to the host, and the host immediately
unassigns the PCI device from the guest; meanwhile,
create_root_hv_pci_bus() and the PCI device driver can be probing the
dead PCI device and reporting timeout errors.

Fix the issue by adding a per-bus mutex 'state_lock' and grabbing the
mutex before powering on the PCI bus in hv_pci_enter_d0(): when
hv_eject_device_work() starts to run, it's able to find the 'pdev' and call
pci_stop_and_remove_bus_device(pdev): if the PCI device driver has
loaded, the PCI device driver's probe() function is already called in
create_root_hv_pci_bus() -&gt; pci_bus_add_devices(), and now
hv_eject_device_work() -&gt; pci_stop_and_remove_bus_device() is able
to call the PCI device driver's remove() function and remove the device
reliably; if the PCI device driver hasn't loaded yet, the function call
hv_eject_device_work() -&gt; pci_stop_and_remove_bus_device() is able to
remove the PCI device reliably and the PCI device driver's probe()
function won't be called; if the PCI device driver's probe() is already
running (e.g., systemd-udev is loading the PCI device driver), it must
be holding the per-device lock, and after the probe() finishes and releases
the lock, hv_eject_device_work() -&gt; pci_stop_and_remove_bus_device() is
able to proceed to remove the device reliably.

Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Lorenzo Pieralisi &lt;lpieralisi@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-6-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally"</title>
<updated>2023-06-18T03:05:39+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-06-15T04:44:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a847234e24d03d01a9566d1d9dcce018cc018d67'/>
<id>a847234e24d03d01a9566d1d9dcce018cc018d67</id>
<content type='text'>
This reverts commit d6af2ed29c7c1c311b96dac989dcb991e90ee195.

The statement "the hv_pci_bus_exit() call releases structures of all its
child devices" in commit d6af2ed29c7c is not true: in the path
hv_pci_probe() -&gt; hv_pci_enter_d0() -&gt; hv_pci_bus_exit(hdev, true): the
parameter "keep_devs" is true, so hv_pci_bus_exit() does *not* release the
child "struct hv_pci_dev *hpdev" that is created earlier in
pci_devices_present_work() -&gt; new_pcichild_device().

The commit d6af2ed29c7c was originally made in July 2020 for RHEL 7.7,
where the old version of hv_pci_bus_exit() was used; when the commit was
rebased and merged into the upstream, people didn't notice that it's
not really necessary. The commit itself doesn't cause any issue, but it
makes hv_pci_probe() more complicated. Revert it to facilitate some
upcoming changes to hv_pci_probe().

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Wei Hu &lt;weh@microsoft.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-5-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This reverts commit d6af2ed29c7c1c311b96dac989dcb991e90ee195.

The statement "the hv_pci_bus_exit() call releases structures of all its
child devices" in commit d6af2ed29c7c is not true: in the path
hv_pci_probe() -&gt; hv_pci_enter_d0() -&gt; hv_pci_bus_exit(hdev, true): the
parameter "keep_devs" is true, so hv_pci_bus_exit() does *not* release the
child "struct hv_pci_dev *hpdev" that is created earlier in
pci_devices_present_work() -&gt; new_pcichild_device().

The commit d6af2ed29c7c was originally made in July 2020 for RHEL 7.7,
where the old version of hv_pci_bus_exit() was used; when the commit was
rebased and merged into the upstream, people didn't notice that it's
not really necessary. The commit itself doesn't cause any issue, but it
makes hv_pci_probe() more complicated. Revert it to facilitate some
upcoming changes to hv_pci_probe().

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Wei Hu &lt;weh@microsoft.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-5-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev</title>
<updated>2023-06-18T03:05:39+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-06-15T04:44:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=add9195e69c94b32e96f78c2f9cea68f0e850b3f'/>
<id>add9195e69c94b32e96f78c2f9cea68f0e850b3f</id>
<content type='text'>
The hpdev-&gt;state is never really useful. The only use in
hv_pci_eject_device() and hv_eject_device_work() is not really necessary.

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Lorenzo Pieralisi &lt;lpieralisi@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-4-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The hpdev-&gt;state is never really useful. The only use in
hv_pci_eject_device() and hv_eject_device_work() is not really necessary.

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Lorenzo Pieralisi &lt;lpieralisi@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-4-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic</title>
<updated>2023-06-18T03:05:39+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-06-15T04:44:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2738d5ab7929a845b654cd171a1e275c37eb428e'/>
<id>2738d5ab7929a845b654cd171a1e275c37eb428e</id>
<content type='text'>
When the host tries to remove a PCI device, the host first sends a
PCI_EJECT message to the guest, and the guest is supposed to gracefully
remove the PCI device and send a PCI_EJECTION_COMPLETE message to the host;
the host then sends a VMBus message CHANNELMSG_RESCIND_CHANNELOFFER to
the guest (when the guest receives this message, the device is already
unassigned from the guest) and the guest can do some final cleanup work;
if the guest fails to respond to the PCI_EJECT message within one minute,
the host sends the VMBus message CHANNELMSG_RESCIND_CHANNELOFFER and
removes the PCI device forcibly.

In the case of fast device addition/removal, it's possible that the PCI
device driver is still configuring MSI-X interrupts when the guest receives
the PCI_EJECT message; the channel callback calls hv_pci_eject_device(),
which sets hpdev-&gt;state to hv_pcichild_ejecting, and schedules a work
hv_eject_device_work(); if the PCI device driver is calling
pci_alloc_irq_vectors() -&gt; ... -&gt; hv_compose_msi_msg(), we can break the
while loop in hv_compose_msi_msg() due to the updated hpdev-&gt;state, and
leave data-&gt;chip_data with its default value of NULL; later, when the PCI
device driver calls request_irq() -&gt; ... -&gt; hv_irq_unmask(), the guest
crashes in hv_arch_irq_unmask() due to data-&gt;chip_data being NULL.

Fix the issue by not testing hpdev-&gt;state in the while loop: when the
guest receives PCI_EJECT, the device is still assigned to the guest, and
the guest has one minute to finish the device removal gracefully. We don't
really need to (and we should not) test hpdev-&gt;state in the loop.

Fixes: de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-3-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the host tries to remove a PCI device, the host first sends a
PCI_EJECT message to the guest, and the guest is supposed to gracefully
remove the PCI device and send a PCI_EJECTION_COMPLETE message to the host;
the host then sends a VMBus message CHANNELMSG_RESCIND_CHANNELOFFER to
the guest (when the guest receives this message, the device is already
unassigned from the guest) and the guest can do some final cleanup work;
if the guest fails to respond to the PCI_EJECT message within one minute,
the host sends the VMBus message CHANNELMSG_RESCIND_CHANNELOFFER and
removes the PCI device forcibly.

In the case of fast device addition/removal, it's possible that the PCI
device driver is still configuring MSI-X interrupts when the guest receives
the PCI_EJECT message; the channel callback calls hv_pci_eject_device(),
which sets hpdev-&gt;state to hv_pcichild_ejecting, and schedules a work
hv_eject_device_work(); if the PCI device driver is calling
pci_alloc_irq_vectors() -&gt; ... -&gt; hv_compose_msi_msg(), we can break the
while loop in hv_compose_msi_msg() due to the updated hpdev-&gt;state, and
leave data-&gt;chip_data with its default value of NULL; later, when the PCI
device driver calls request_irq() -&gt; ... -&gt; hv_irq_unmask(), the guest
crashes in hv_arch_irq_unmask() due to data-&gt;chip_data being NULL.

Fix the issue by not testing hpdev-&gt;state in the while loop: when the
guest receives PCI_EJECT, the device is still assigned to the guest, and
the guest has one minute to finish the device removal gracefully. We don't
really need to (and we should not) test hpdev-&gt;state in the loop.

Fixes: de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-3-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: hv: Fix a race condition bug in hv_pci_query_relations()</title>
<updated>2023-06-18T03:05:39+00:00</updated>
<author>
<name>Dexuan Cui</name>
<email>decui@microsoft.com</email>
</author>
<published>2023-06-15T04:44:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=440b5e3663271b0ffbd4908115044a6a51fb938b'/>
<id>440b5e3663271b0ffbd4908115044a6a51fb938b</id>
<content type='text'>
Since day 1 of the driver, there has been a race between
hv_pci_query_relations() and survey_child_resources(): during fast
device hotplug, hv_pci_query_relations() may error out due to
device-remove and the stack variable 'comp' is no longer valid;
however, pci_devices_present_work() -&gt; survey_child_resources() -&gt;
complete() may be running on another CPU and accessing the no-longer-valid
'comp'. Fix the race by flushing the workqueue before we exit from
hv_pci_query_relations().

Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Lorenzo Pieralisi &lt;lpieralisi@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-2-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since day 1 of the driver, there has been a race between
hv_pci_query_relations() and survey_child_resources(): during fast
device hotplug, hv_pci_query_relations() may error out due to
device-remove and the stack variable 'comp' is no longer valid;
however, pci_devices_present_work() -&gt; survey_child_resources() -&gt;
complete() may be running on another CPU and accessing the no-longer-valid
'comp'. Fix the race by flushing the workqueue before we exit from
hv_pci_query_relations().

Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Acked-by: Lorenzo Pieralisi &lt;lpieralisi@kernel.org&gt;
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-2-decui@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/DPC: Quirk PIO log size for Intel Ice Lake Root Ports</title>
<updated>2023-05-11T22:38:46+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2023-05-11T12:19:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3b8803494a0612acdeee714cb72aa142b1e05ce5'/>
<id>3b8803494a0612acdeee714cb72aa142b1e05ce5</id>
<content type='text'>
Commit 5459c0b70467 ("PCI/DPC: Quirk PIO log size for certain Intel Root
Ports") added quirks for Tiger and Alder Lake Root Ports but missed that
the same issue exists also in the previous generation, Ice Lake.

Apply the quirk for Ice Lake Root Ports as well.  This prevents kernel
complaints like:

  DPC: RP PIO log size 0 is invalid

and also enables the DPC driver to dump the RP PIO Log registers when DPC
is triggered.

[bhelgaas: add dmesg warning and RP PIO Log dump info]
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=209943
Link: https://lore.kernel.org/r/20230511121905.73949-1-mika.westerberg@linux.intel.com
Reported-by: Mark Blakeney &lt;mark.blakeney@bullet-systems.net&gt;
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 5459c0b70467 ("PCI/DPC: Quirk PIO log size for certain Intel Root
Ports") added quirks for Tiger and Alder Lake Root Ports but missed that
the same issue exists also in the previous generation, Ice Lake.

Apply the quirk for Ice Lake Root Ports as well.  This prevents kernel
complaints like:

  DPC: RP PIO log size 0 is invalid

and also enables the DPC driver to dump the RP PIO Log registers when DPC
is triggered.

[bhelgaas: add dmesg warning and RP PIO Log dump info]
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=209943
Link: https://lore.kernel.org/r/20230511121905.73949-1-mika.westerberg@linux.intel.com
Reported-by: Mark Blakeney &lt;mark.blakeney@bullet-systems.net&gt;
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'cxl-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl</title>
<updated>2023-04-30T18:51:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-30T18:51:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7acc1372113083fa281ba426021801e2402caca1'/>
<id>7acc1372113083fa281ba426021801e2402caca1</id>
<content type='text'>
Pull compute express link updates from Dan Williams:
 "DOE support is promoted from drivers/cxl/ to drivers/pci/ with Bjorn's
  blessing, and the CXL core continues to mature its media management
  capabilities with support for listing and injecting media errors. Some
  late fixes that missed v6.3-final are also included:

   - Refactor the DOE infrastructure (Data Object Exchange
     PCI-config-cycle mailbox) to be a facility of the PCI core rather
     than the CXL core.

     This is foundational for upcoming support for PCI
     device-attestation and PCIe / CXL link encryption.

   - Add support for retrieving and injecting poison for CXL memory
     expanders.

     This enabling uses trace-events to convey CXL media error records
     to user tooling. It includes translation of device-local addresses
     (DPA) to system physical addresses (SPA) and their corresponding
     CXL region.

   - Fixes for decoder enumeration that missed v6.3-final

   - Miscellaneous fixups"

* tag 'cxl-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (38 commits)
  cxl/test: Add mock test for set_timestamp
  cxl/mbox: Update CMD_RC_TABLE
  tools/testing/cxl: Require CONFIG_DEBUG_FS
  tools/testing/cxl: Add a sysfs attr to test poison inject limits
  tools/testing/cxl: Use injected poison for get poison list
  tools/testing/cxl: Mock the Clear Poison mailbox command
  tools/testing/cxl: Mock the Inject Poison mailbox command
  cxl/mem: Add debugfs attributes for poison inject and clear
  cxl/memdev: Trace inject and clear poison as cxl_poison events
  cxl/memdev: Warn of poison inject or clear to a mapped region
  cxl/memdev: Add support for the Clear Poison mailbox command
  cxl/memdev: Add support for the Inject Poison mailbox command
  tools/testing/cxl: Mock support for Get Poison List
  cxl/trace: Add an HPA to cxl_poison trace events
  cxl/region: Provide region info to the cxl_poison trace event
  cxl/memdev: Add trigger_poison_list sysfs attribute
  cxl/trace: Add TRACE support for CXL media-error records
  cxl/mbox: Add GET_POISON_LIST mailbox command
  cxl/mbox: Initialize the poison state
  cxl/mbox: Restrict poison cmds to debugfs cxl_raw_allow_all
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull compute express link updates from Dan Williams:
 "DOE support is promoted from drivers/cxl/ to drivers/pci/ with Bjorn's
  blessing, and the CXL core continues to mature its media management
  capabilities with support for listing and injecting media errors. Some
  late fixes that missed v6.3-final are also included:

   - Refactor the DOE infrastructure (Data Object Exchange
     PCI-config-cycle mailbox) to be a facility of the PCI core rather
     than the CXL core.

     This is foundational for upcoming support for PCI
     device-attestation and PCIe / CXL link encryption.

   - Add support for retrieving and injecting poison for CXL memory
     expanders.

     This enabling uses trace-events to convey CXL media error records
     to user tooling. It includes translation of device-local addresses
     (DPA) to system physical addresses (SPA) and their corresponding
     CXL region.

   - Fixes for decoder enumeration that missed v6.3-final

   - Miscellaneous fixups"

* tag 'cxl-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (38 commits)
  cxl/test: Add mock test for set_timestamp
  cxl/mbox: Update CMD_RC_TABLE
  tools/testing/cxl: Require CONFIG_DEBUG_FS
  tools/testing/cxl: Add a sysfs attr to test poison inject limits
  tools/testing/cxl: Use injected poison for get poison list
  tools/testing/cxl: Mock the Clear Poison mailbox command
  tools/testing/cxl: Mock the Inject Poison mailbox command
  cxl/mem: Add debugfs attributes for poison inject and clear
  cxl/memdev: Trace inject and clear poison as cxl_poison events
  cxl/memdev: Warn of poison inject or clear to a mapped region
  cxl/memdev: Add support for the Clear Poison mailbox command
  cxl/memdev: Add support for the Inject Poison mailbox command
  tools/testing/cxl: Mock support for Get Poison List
  cxl/trace: Add an HPA to cxl_poison trace events
  cxl/region: Provide region info to the cxl_poison trace event
  cxl/memdev: Add trigger_poison_list sysfs attribute
  cxl/trace: Add TRACE support for CXL media-error records
  cxl/mbox: Add GET_POISON_LIST mailbox command
  cxl/mbox: Initialize the poison state
  cxl/mbox: Restrict poison cmds to debugfs cxl_raw_allow_all
  ...
</pre>
</div>
</content>
</entry>
</feed>
