linux-stable.git/drivers/pci/controller, branch v6.4.2

PCI: hv: Add a per-bus mutex state_lock

2023-06-18T03:05:40+00:00

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 
Reviewed-by: Michael Kelley 
Acked-by: Lorenzo Pieralisi 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-6-decui@microsoft.com
Signed-off-by: Wei Liu

Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally"

2023-06-18T03:05:39+00:00

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 
Reviewed-by: Michael Kelley 
Acked-by: Wei Hu 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-5-decui@microsoft.com
Signed-off-by: Wei Liu

PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev

2023-06-18T03:05:39+00:00

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 
Reviewed-by: Michael Kelley 
Acked-by: Lorenzo Pieralisi 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-4-decui@microsoft.com
Signed-off-by: Wei Liu

PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic

2023-06-18T03:05:39+00:00

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 
Reviewed-by: Michael Kelley 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-3-decui@microsoft.com
Signed-off-by: Wei Liu

PCI: hv: Fix a race condition bug in hv_pci_query_relations()

2023-06-18T03:05:39+00:00

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 
Reviewed-by: Michael Kelley 
Acked-by: Lorenzo Pieralisi 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230615044451.5580-2-decui@microsoft.com
Signed-off-by: Wei Liu

Merge tag 'hyperv-next-signed-20230424' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

2023-04-28T00:17:12+00:00

Pull hyperv updates from Wei Liu:

 - PCI passthrough for Hyper-V confidential VMs (Michael Kelley)

 - Hyper-V VTL mode support (Saurabh Sengar)

 - Move panic report initialization code earlier (Long Li)

 - Various improvements and bug fixes (Dexuan Cui and Michael Kelley)

* tag 'hyperv-next-signed-20230424' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits)
  PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg
  Drivers: hv: move panic report code from vmbus to hv early init code
  x86/hyperv: VTL support for Hyper-V
  Drivers: hv: Kconfig: Add HYPERV_VTL_MODE
  x86/hyperv: Make hv_get_nmi_reason public
  x86/hyperv: Add VTL specific structs and hypercalls
  x86/init: Make get/set_rtc_noop() public
  x86/hyperv: Exclude lazy TLB mode CPUs from enlightened TLB flushes
  x86/hyperv: Add callback filter to cpumask_to_vpset()
  Drivers: hv: vmbus: Remove the per-CPU post_msg_page
  clocksource: hyper-v: make sure Invariant-TSC is used if it is available
  PCI: hv: Enable PCI pass-thru devices in Confidential VMs
  Drivers: hv: Don't remap addresses that are above shared_gpa_boundary
  hv_netvsc: Remove second mapping of send and recv buffers
  Drivers: hv: vmbus: Remove second way of mapping ring buffers
  Drivers: hv: vmbus: Remove second mapping of VMBus monitor pages
  swiotlb: Remove bounce buffer remapping for Hyper-V
  Driver: VMBus: Add Devicetree support
  dt-bindings: bus: Add Hyper-V VMBus
  Drivers: hv: vmbus: Convert acpi_device to more generic platform_device
  ...

Merge tag 'pci-v6.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci

2023-04-27T17:45:30+00:00

Pull pci updates from Bjorn Helgaas:
 "Resource management:

   - Add pci_dev_for_each_resource() and pci_bus_for_each_resource()
     iterators

  PCIe native device hotplug:

   - Fix AB-BA deadlock between reset_lock and device_lock

  Power management:

   - Wait longer for devices to become ready after resume (as we do for
     reset) to accommodate Intel Titan Ridge xHCI devices

   - Extend D3hot delay for NVIDIA HDA controllers to avoid
     unrecoverable devices after a bus reset

  Error handling:

   - Clear PCIe Device Status after EDR since generic error recovery now
     only clears it when AER is native

  ASPM:

   - Work around Chromebook firmware defect that clobbers Capability
     list (including ASPM L1 PM Substates Cap) when returning from
     D3cold to D0

  Freescale i.MX6 PCIe controller driver:

   - Install imprecise external abort handler only when DT indicates
     PCIe support

  Freescale Layerscape PCIe controller driver:

   - Add ls1028a endpoint mode support

  Qualcomm PCIe controller driver:

   - Add SM8550 DT binding and driver support

   - Add SDX55 DT binding and driver support

   - Use bulk APIs for clocks of IP 1.0.0, 2.3.2, 2.3.3

   - Use bulk APIs for reset of IP 2.1.0, 2.3.3, 2.4.0

   - Add DT "mhi" register region for supported SoCs

   - Expose link transition counts via debugfs to help debug low power
     issues

   - Support system suspend and resume; reduce interconnect bandwidth
     and turn off clock and PHY if there are no active devices

   - Enable async probe by default to reduce boot time

  Miscellaneous:

   - Sort controller Kconfig entries by vendor"

* tag 'pci-v6.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci: (56 commits)
  PCI: xilinx: Drop obsolete dependency on COMPILE_TEST
  PCI: mobiveil: Sort Kconfig entries by vendor
  PCI: dwc: Sort Kconfig entries by vendor
  PCI: Sort controller Kconfig entries by vendor
  PCI: Use consistent controller Kconfig menu entry language
  PCI: xilinx-nwl: Add 'Xilinx' to Kconfig prompt
  PCI: hv: Add 'Microsoft' to Kconfig prompt
  PCI: meson: Add 'Amlogic' to Kconfig prompt
  PCI: Use of_property_present() for testing DT property presence
  PCI/PM: Extend D3hot delay for NVIDIA HDA controllers
  dt-bindings: PCI: qcom: Document msi-map and msi-map-mask properties
  PCI: qcom: Add SM8550 PCIe support
  dt-bindings: PCI: qcom: Add SM8550 compatible
  PCI: qcom: Add support for SDX55 SoC
  dt-bindings: PCI: qcom-ep: Fix the unit address used in example
  dt-bindings: PCI: qcom: Add SDX55 SoC
  dt-bindings: PCI: qcom: Update maintainers entry
  PCI: qcom: Enable async probe by default
  PCI: qcom: Add support for system suspend and resume
  PCI/PM: Drop pci_bridge_wait_for_secondary_bus() timeout parameter
  ...

PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg

2023-04-21T21:25:23+00:00

4 commits are involved here:
A (2016): commit 0de8ce3ee8e3 ("PCI: hv: Allocate physically contiguous hypercall params buffer")
B (2017): commit be66b6736591 ("PCI: hv: Use page allocation for hbus structure")
C (2019): commit 877b911a5ba0 ("PCI: hv: Avoid a kmemleak false positive caused by the hbus buffer")
D (2018): commit 68bb7bfb7985 ("X86/Hyper-V: Enable IPI enlightenments")

Patch D introduced the per-CPU hypercall input page "hyperv_pcpu_input_arg"
in 2018. With patch D, we no longer need the per-Hyper-V-PCI-bus hypercall
input page "hbus->retarget_msi_interrupt_params" that was added in patch A,
and the issue addressed by patch B is no longer an issue, and we can also
get rid of patch C.

The change here is required for PCI device assignment to work for
Confidential VMs (CVMs) running without a paravisor, because otherwise we
would have to call set_memory_decrypted() for
"hbus->retarget_msi_interrupt_params" before calling the hypercall
HVCALL_RETARGET_INTERRUPT.

Signed-off-by: Dexuan Cui 
Reviewed-by: Michael Kelley 
Acked-by: Lorenzo Pieralisi 
Link: https://lore.kernel.org/r/20230421013025.17152-1-decui@microsoft.com
Signed-off-by: Wei Liu

PCI: xilinx: Drop obsolete dependency on COMPILE_TEST

2023-04-20T21:18:05+00:00

Since commit 0166dc11be91 ("of: make CONFIG_OF user selectable"), it is
possible to test-build any driver which depends on OF on any architecture
by explicitly selecting OF. Therefore depending on COMPILE_TEST as an
alternative is no longer needed.

Link: https://lore.kernel.org/r/20230407190843.529caf19@endymion.delvare
Signed-off-by: Jean Delvare 
Signed-off-by: Bjorn Helgaas 
Cc: Lorenzo Pieralisi 
Cc: Rob Herring 
Cc: "Krzysztof Wilczyński"

PCI: mobiveil: Sort Kconfig entries by vendor

2023-04-20T21:18:05+00:00

Sort Kconfig entries by vendor so they appear in alphabetical order in
menuconfig.

Link: https://lore.kernel.org/r/20230418174336.145585-8-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas