linux-stable.git/drivers/pci, branch v6.3.12 Linux kernel stable tree PCI/ACPI: Call _REG when transitioning D-states 2023-07-05T17:29:23+00:00 Mario Limonciello mario.limonciello@amd.com 2023-06-20T14:04:51+00:00 5e8e8a91475d97d9562b73c0d72c18f38fc78514 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 <mario.limonciello@amd.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Rafael J. Wysocki <rafael@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <mario.limonciello@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI/ACPI: Validate acpi_pci_set_power_state() parameter 2023-07-05T17:29:23+00:00 Bjorn Helgaas bhelgaas@google.com 2023-06-21T21:36:12+00:00 47a1227141fc798d4e8f774bd7655d1741960fcd 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 <bhelgaas@google.com> Reviewed-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
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 <bhelgaas@google.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI: hv: Add a per-bus mutex state_lock 2023-06-28T09:14:06+00:00 Dexuan Cui decui@microsoft.com 2023-06-15T04:44:51+00:00 4a1d32de8abc5c4927e981189922c81b9d77fc0f commit 067d6ec7ed5b49380688e06c1e5f883a71bef4fe upstream. 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() -> pci_bus_add_devices(), and now hv_eject_device_work() -> 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() -> 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() -> 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 <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230615044451.5580-6-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 067d6ec7ed5b49380688e06c1e5f883a71bef4fe upstream.

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() -> pci_bus_add_devices(), and now
hv_eject_device_work() -> 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() -> 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() -> 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 <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-6-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic 2023-06-28T09:14:06+00:00 Dexuan Cui decui@microsoft.com 2023-06-15T04:44:48+00:00 27b44e8f9f6afed86fe8228fe448f890f485a978 commit 2738d5ab7929a845b654cd171a1e275c37eb428e upstream. 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->state to hv_pcichild_ejecting, and schedules a work hv_eject_device_work(); if the PCI device driver is calling pci_alloc_irq_vectors() -> ... -> hv_compose_msi_msg(), we can break the while loop in hv_compose_msi_msg() due to the updated hpdev->state, and leave data->chip_data with its default value of NULL; later, when the PCI device driver calls request_irq() -> ... -> hv_irq_unmask(), the guest crashes in hv_arch_irq_unmask() due to data->chip_data being NULL. Fix the issue by not testing hpdev->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->state in the loop. Fixes: de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230615044451.5580-3-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2738d5ab7929a845b654cd171a1e275c37eb428e upstream.

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->state to hv_pcichild_ejecting, and schedules a work
hv_eject_device_work(); if the PCI device driver is calling
pci_alloc_irq_vectors() -> ... -> hv_compose_msi_msg(), we can break the
while loop in hv_compose_msi_msg() due to the updated hpdev->state, and
leave data->chip_data with its default value of NULL; later, when the PCI
device driver calls request_irq() -> ... -> hv_irq_unmask(), the guest
crashes in hv_arch_irq_unmask() due to data->chip_data being NULL.

Fix the issue by not testing hpdev->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->state in the loop.

Fixes: de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-3-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev 2023-06-28T09:14:06+00:00 Dexuan Cui decui@microsoft.com 2023-06-15T04:44:49+00:00 2b8b666dd848ec444f18fb027ffdddef38e548db commit add9195e69c94b32e96f78c2f9cea68f0e850b3f upstream. The hpdev->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 <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230615044451.5580-4-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit add9195e69c94b32e96f78c2f9cea68f0e850b3f upstream.

The hpdev->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 <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-4-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally" 2023-06-28T09:14:06+00:00 Dexuan Cui decui@microsoft.com 2023-06-15T04:44:50+00:00 55e6ecd8fd278a10fc0b3fc61f2f8d5f15809591 commit a847234e24d03d01a9566d1d9dcce018cc018d67 upstream. 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() -> hv_pci_enter_d0() -> 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() -> 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 <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Wei Hu <weh@microsoft.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230615044451.5580-5-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a847234e24d03d01a9566d1d9dcce018cc018d67 upstream.

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() -> hv_pci_enter_d0() -> 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() -> 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 <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Wei Hu <weh@microsoft.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-5-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI: hv: Fix a race condition bug in hv_pci_query_relations() 2023-06-28T09:14:05+00:00 Dexuan Cui decui@microsoft.com 2023-06-15T04:44:47+00:00 447123893d3fbfd265e6573401cfca560dbd7b90 commit 440b5e3663271b0ffbd4908115044a6a51fb938b upstream. 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() -> survey_child_resources() -> 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 <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230615044451.5580-2-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 440b5e3663271b0ffbd4908115044a6a51fb938b upstream.

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() -> survey_child_resources() ->
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 <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-2-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PCI/DPC: Quirk PIO log size for Intel Ice Lake Root Ports 2023-06-21T14:02:06+00:00 Mika Westerberg mika.westerberg@linux.intel.com 2023-05-11T12:19:05+00:00 1188afef30509eed231a9fbcf58f9e38e6b07faf [ Upstream commit 3b8803494a0612acdeee714cb72aa142b1e05ce5 ] 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 <mark.blakeney@bullet-systems.net> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3b8803494a0612acdeee714cb72aa142b1e05ce5 ]

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 <mark.blakeney@bullet-systems.net>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
PCI/PM: Extend D3hot delay for NVIDIA HDA controllers 2023-05-11T14:17:27+00:00 Alex Williamson alex.williamson@redhat.com 2023-04-13T19:40:42+00:00 4039b58e16b9153f1ee2d0ac4ab0672b2e963494 [ Upstream commit a5a6dd2624698b6e3045c3a1450874d8c790d5d9 ] Assignment of NVIDIA Ampere-based GPUs have seen a regression since the below referenced commit, where the reduced D3hot transition delay appears to introduce a small window where a D3hot->D0 transition followed by a bus reset can wedge the device. The entire device is subsequently unavailable, returning -1 on config space read and is unrecoverable without a host reset. This has been observed with RTX A2000 and A5000 GPU and audio functions assigned to a Windows VM, where shutdown of the VM places the devices in D3hot prior to vfio-pci performing a bus reset when userspace releases the devices. The issue has roughly a 2-3% chance of occurring per shutdown. Restoring the HDA controller d3hot_delay to the effective value before the below commit has been shown to resolve the issue. NVIDIA confirms this change should be safe for all of their HDA controllers. Fixes: 3e347969a577 ("PCI/PM: Reduce D3hot delay with usleep_range()") Link: https://lore.kernel.org/r/20230413194042.605768-1-alex.williamson@redhat.com Reported-by: Zhiyi Guo <zhguo@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Tarun Gupta <targupta@nvidia.com> Cc: Abhishek Sahu <abhsahu@nvidia.com> Cc: Tarun Gupta <targupta@nvidia.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a5a6dd2624698b6e3045c3a1450874d8c790d5d9 ]

Assignment of NVIDIA Ampere-based GPUs have seen a regression since the
below referenced commit, where the reduced D3hot transition delay appears
to introduce a small window where a D3hot->D0 transition followed by a bus
reset can wedge the device.  The entire device is subsequently unavailable,
returning -1 on config space read and is unrecoverable without a host
reset.

This has been observed with RTX A2000 and A5000 GPU and audio functions
assigned to a Windows VM, where shutdown of the VM places the devices in
D3hot prior to vfio-pci performing a bus reset when userspace releases the
devices.  The issue has roughly a 2-3% chance of occurring per shutdown.

Restoring the HDA controller d3hot_delay to the effective value before the
below commit has been shown to resolve the issue.  NVIDIA confirms this
change should be safe for all of their HDA controllers.

Fixes: 3e347969a577 ("PCI/PM: Reduce D3hot delay with usleep_range()")
Link: https://lore.kernel.org/r/20230413194042.605768-1-alex.williamson@redhat.com
Reported-by: Zhiyi Guo <zhguo@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Tarun Gupta <targupta@nvidia.com>
Cc: Abhishek Sahu <abhsahu@nvidia.com>
Cc: Tarun Gupta <targupta@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
PCI/EDR: Clear Device Status after EDR error recovery 2023-05-11T14:17:25+00:00 Kuppuswamy Sathyanarayanan sathyanarayanan.kuppuswamy@linux.intel.com 2023-03-15T23:54:49+00:00 9288c4f1dc860d093098f8667f740c6bb332eee9 [ Upstream commit c441b1e03da6c680a3e12da59c554f454f2ccf5e ] During EDR recovery, the OS must clear error status of the port that triggered DPC even if firmware retains control of DPC and AER (see the implementation note in the PCI Firmware spec r3.3, sec 4.6.12). Prior to 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if OS owns AER"), the port Device Status was cleared in this path: edr_handle_event dpc_process_error(dev) # "dev" triggered DPC pcie_do_recovery(dev, dpc_reset_link) dpc_reset_link # exit DPC pcie_clear_device_status(dev) # clear Device Status After 068c29a248b6, pcie_do_recovery() no longer clears Device Status when firmware controls AER, so the error bit remains set even after recovery. Per the "Downstream Port Containment configuration control" bit in the returned _OSC Control Field (sec 4.5.1), the OS is allowed to clear error status until it evaluates _OST, so clear Device Status in edr_handle_event() if the error recovery was successful. [bhelgaas: commit log] Fixes: 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if OS owns AER") Link: https://lore.kernel.org/r/20230315235449.1279209-1-sathyanarayanan.kuppuswamy@linux.intel.com Reported-by: Tsaur Erwin <erwin.tsaur@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit c441b1e03da6c680a3e12da59c554f454f2ccf5e ]

During EDR recovery, the OS must clear error status of the port that
triggered DPC even if firmware retains control of DPC and AER (see the
implementation note in the PCI Firmware spec r3.3, sec 4.6.12).

Prior to 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if
OS owns AER"), the port Device Status was cleared in this path:

  edr_handle_event
    dpc_process_error(dev)                 # "dev" triggered DPC
    pcie_do_recovery(dev, dpc_reset_link)
      dpc_reset_link                       # exit DPC
      pcie_clear_device_status(dev)        # clear Device Status

After 068c29a248b6, pcie_do_recovery() no longer clears Device Status when
firmware controls AER, so the error bit remains set even after recovery.

Per the "Downstream Port Containment configuration control" bit in the
returned _OSC Control Field (sec 4.5.1), the OS is allowed to clear error
status until it evaluates _OST, so clear Device Status in
edr_handle_event() if the error recovery was successful.

[bhelgaas: commit log]
Fixes: 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status errors only if OS owns AER")
Link: https://lore.kernel.org/r/20230315235449.1279209-1-sathyanarayanan.kuppuswamy@linux.intel.com
Reported-by: Tsaur Erwin <erwin.tsaur@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>