<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel.git/drivers/pci/controller/pci-hyperv.c, branch linux-5.12.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.
</subtitle>
<id>https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.12.y</id>
<link rel='self' href='https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-5.12.y'/>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/'/>
<updated>2021-07-20T14:02:13Z</updated>
<entry>
<title>PCI: hv: Fix a race condition when removing the device</title>
<updated>2021-07-20T14:02:13Z</updated>
<author>
<name>Long Li</name>
</author>
<published>2021-05-12T08:06:40Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=7680ae29086aa4bcf0ceba7341f369f766208a7b'/>
<id>urn:sha1:7680ae29086aa4bcf0ceba7341f369f766208a7b</id>
<content type='text'>
[ Upstream commit 94d22763207ac6633612b8d8e0ca4fba0f7aa139 ]

On removing the device, any work item (hv_pci_devices_present() or
hv_pci_eject_device()) scheduled on workqueue hbus-&gt;wq may still be running
and race with hv_pci_remove().

This can happen because the host may send PCI_EJECT or PCI_BUS_RELATIONS(2)
and decide to rescind the channel immediately after that.

Fix this by flushing/destroying the workqueue of hbus before doing hbus remove.

Link: https://lore.kernel.org/r/1620806800-30983-1-git-send-email-longli@linuxonhyperv.com
Signed-off-by: Long Li &lt;longli@microsoft.com&gt;
Signed-off-by: Lorenzo Pieralisi &lt;lorenzo.pieralisi@arm.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>PCI: hv: Add check for hyperv_initialized in init_hv_pci_drv()</title>
<updated>2021-07-14T14:59:27Z</updated>
<author>
<name>Haiyang Zhang</name>
</author>
<published>2021-05-25T23:17:33Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=71f33bceaf802bce68667d4342c6a5ccb18878df'/>
<id>urn:sha1:71f33bceaf802bce68667d4342c6a5ccb18878df</id>
<content type='text'>
[ Upstream commit 7d815f4afa87f2032b650ae1bba7534b550a6b8b ]

Add check for hv_is_hyperv_initialized() at the top of
init_hv_pci_drv(), so if the pci-hyperv driver is force-loaded on non
Hyper-V platforms, the init_hv_pci_drv() will exit immediately, without
any side effects, like assignments to hvpci_block_ops, etc.

Signed-off-by: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Reported-and-tested-by: Mohammad Alqayeem &lt;mohammad.alqyeem@nutanix.com&gt;
Reviewed-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Link: https://lore.kernel.org/r/1621984653-1210-1-git-send-email-haiyangz@microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'pci-v5.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci</title>
<updated>2021-02-25T17:56:08Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2021-02-25T17:56:08Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=5b47b10e8fb92f8beca6aa8a7d97fc84e090384c'/>
<id>urn:sha1:5b47b10e8fb92f8beca6aa8a7d97fc84e090384c</id>
<content type='text'>
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:
   - Remove unnecessary locking around _OSC (Bjorn Helgaas)
   - Clarify message about _OSC failure (Bjorn Helgaas)
   - Remove notification of PCIe bandwidth changes (Bjorn Helgaas)
   - Tidy checking of syscall user config accessors (Heiner Kallweit)

  Resource management:
   - Decline to resize resources if boot config must be preserved (Ard
     Biesheuvel)
   - Fix pci_register_io_range() memory leak (Geert Uytterhoeven)

  Error handling (Keith Busch):
   - Clear error status from the correct device
   - Retain error recovery status so drivers can use it after reset
   - Log the type of Port (Root or Switch Downstream) that we reset
   - Always request a reset for Downstream Ports in frozen state

  Endpoint framework and NTB (Kishon Vijay Abraham I):
   - Make *_get_first_free_bar() take into account 64 bit BAR
   - Add helper API to get the 'next' unreserved BAR
   - Make *_free_bar() return error codes on failure
   - Remove unused pci_epf_match_device()
   - Add support to associate secondary EPC with EPF
   - Add support in configfs to associate two EPCs with EPF
   - Add pci_epc_ops to map MSI IRQ
   - Add pci_epf_ops to expose function-specific attrs
   - Allow user to create sub-directory of 'EPF Device' directory
   - Implement -&gt;msi_map_irq() ops for cadence
   - Configure LM_EP_FUNC_CFG based on epc-&gt;function_num_map for cadence
   - Add EP function driver to provide NTB functionality
   - Add support for EPF PCI Non-Transparent Bridge
   - Add specification for PCI NTB function device
   - Add PCI endpoint NTB function user guide
   - Add configfs binding documentation for pci-ntb endpoint function

  Broadcom STB PCIe controller driver:
   - Add support for BCM4908 and external PERST# signal controller
     (Rafał Miłecki)

  Cadence PCIe controller driver:
   - Retrain Link to work around Gen2 training defect (Nadeem Athani)
   - Fix merge botch in cdns_pcie_host_map_dma_ranges() (Krzysztof
     Wilczyński)

  Freescale Layerscape PCIe controller driver:
   - Add LX2160A rev2 EP mode support (Hou Zhiqiang)
   - Convert to builtin_platform_driver() (Michael Walle)

  MediaTek PCIe controller driver:
   - Fix OF node reference leak (Krzysztof Wilczyński)

  Microchip PolarFlare PCIe controller driver:
   - Add Microchip PolarFire PCIe controller driver (Daire McNamara)

  Qualcomm PCIe controller driver:
   - Use PHY_REFCLK_USE_PAD only for ipq8064 (Ansuel Smith)
   - Add support for ddrss_sf_tbu clock for sm8250 (Dmitry Baryshkov)

  Renesas R-Car PCIe controller driver:
   - Drop PCIE_RCAR config option (Lad Prabhakar)
   - Always allocate MSI addresses in 32bit space (Marek Vasut)

  Rockchip PCIe controller driver:
   - Add FriendlyARM NanoPi M4B DT binding (Chen-Yu Tsai)
   - Make 'ep-gpios' DT property optional (Chen-Yu Tsai)

  Synopsys DesignWare PCIe controller driver:
   - Work around ECRC configuration hardware defect (Vidya Sagar)
   - Drop support for config space in DT 'ranges' (Rob Herring)
   - Change size to u64 for EP outbound iATU (Shradha Todi)
   - Add upper limit address for outbound iATU (Shradha Todi)
   - Make dw_pcie ops optional (Jisheng Zhang)
   - Remove unnecessary dw_pcie_ops from al driver (Jisheng Zhang)

  Xilinx Versal CPM PCIe controller driver:
   - Fix OF node reference leak (Pan Bian)

  Miscellaneous:
   - Remove tango host controller driver (Arnd Bergmann)
   - Remove IRQ handler &amp; data together (altera-msi, brcmstb, dwc)
     (Martin Kaiser)
   - Fix xgene-msi race in installing chained IRQ handler (Martin
     Kaiser)
   - Apply CONFIG_PCI_DEBUG to entire drivers/pci hierarchy (Junhao He)
   - Fix pci-bridge-emul array overruns (Russell King)
   - Remove obsolete uses of WARN_ON(in_interrupt()) (Sebastian Andrzej
     Siewior)"

* tag 'pci-v5.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (69 commits)
  PCI: qcom: Use PHY_REFCLK_USE_PAD only for ipq8064
  PCI: qcom: Add support for ddrss_sf_tbu clock
  dt-bindings: PCI: qcom: Document ddrss_sf_tbu clock for sm8250
  PCI: al: Remove useless dw_pcie_ops
  PCI: dwc: Don't assume the ops in dw_pcie always exist
  PCI: dwc: Add upper limit address for outbound iATU
  PCI: dwc: Change size to u64 for EP outbound iATU
  PCI: dwc: Drop support for config space in 'ranges'
  PCI: layerscape: Convert to builtin_platform_driver()
  PCI: layerscape: Add LX2160A rev2 EP mode support
  dt-bindings: PCI: layerscape: Add LX2160A rev2 compatible strings
  PCI: dwc: Work around ECRC configuration issue
  PCI/portdrv: Report reset for frozen channel
  PCI/AER: Specify the type of Port that was reset
  PCI/ERR: Retain status from error notification
  PCI/AER: Clear AER status from Root Port when resetting Downstream Port
  PCI/ERR: Clear status of the reporting device
  dt-bindings: arm: rockchip: Add FriendlyARM NanoPi M4B
  PCI: rockchip: Make 'ep-gpios' DT property optional
  Documentation: PCI: Add PCI endpoint NTB function user guide
  ...
</content>
</entry>
<entry>
<title>asm-generic/hyperv: update hv_interrupt_entry</title>
<updated>2021-02-11T08:47:06Z</updated>
<author>
<name>Wei Liu</name>
</author>
<published>2021-02-03T15:04:31Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=b59fb7b60d47b2af3a114daf0ae198aa23921698'/>
<id>urn:sha1:b59fb7b60d47b2af3a114daf0ae198aa23921698</id>
<content type='text'>
We will soon use the same structure to handle IO-APIC interrupts as
well. Introduce an enum to identify the source and a data structure for
IO-APIC RTE.

While at it, update pci-hyperv.c to use the enum.

No functional change.

Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Acked-by: Rob Herring &lt;robh@kernel.org&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Link: https://lore.kernel.org/r/20210203150435.27941-13-wei.liu@kernel.org
</content>
</entry>
<entry>
<title>PCI: hv: Fix typo</title>
<updated>2021-01-28T10:48:47Z</updated>
<author>
<name>Bjorn Helgaas</name>
</author>
<published>2021-01-26T21:38:55Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=c77bfb5417430832aae54a251a340c8f05682b3f'/>
<id>urn:sha1:c77bfb5417430832aae54a251a340c8f05682b3f</id>
<content type='text'>
Fix misspelling of "silently".

Link: https://lore.kernel.org/r/20210126213855.2923461-1-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Lorenzo Pieralisi &lt;lorenzo.pieralisi@arm.com&gt;
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
</content>
</entry>
<entry>
<title>x86/apic: Cleanup delivery mode defines</title>
<updated>2020-10-28T19:26:24Z</updated>
<author>
<name>Thomas Gleixner</name>
</author>
<published>2020-10-24T21:35:05Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=721612994f53ed600b39a80d912b10f51960e2e3'/>
<id>urn:sha1:721612994f53ed600b39a80d912b10f51960e2e3</id>
<content type='text'>
The enum ioapic_irq_destination_types and the enumerated constants starting
with 'dest_' are gross misnomers because they describe the delivery mode.

Rename then enum and the constants so they actually make sense.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: David Woodhouse &lt;dwmw@amazon.co.uk&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: https://lore.kernel.org/r/20201024213535.443185-6-dwmw2@infradead.org

</content>
</entry>
<entry>
<title>Merge tag 'pci-v5.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci</title>
<updated>2020-10-22T19:41:00Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2020-10-22T19:41:00Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=00937f36b09e89c74e4a059dbb8acbf4b971d5eb'/>
<id>urn:sha1:00937f36b09e89c74e4a059dbb8acbf4b971d5eb</id>
<content type='text'>
Pull PCI updates from Bjorn Helgaas:
 "Enumeration:
   - Print IRQ number used by PCIe Link Bandwidth Notification (Dongdong
     Liu)
   - Add schedule point in pci_read_config() to reduce max latency
     (Jiang Biao)
   - Add Kconfig options for MPS/MRRS strategy (Jim Quinlan)

  Resource management:
   - Fix pci_iounmap() memory leak when !CONFIG_GENERIC_IOMAP (Lorenzo
     Pieralisi)

  PCIe native device hotplug:
   - Reduce noisiness on hot removal (Lukas Wunner)

  Power management:
   - Revert "PCI/PM: Apply D2 delay as milliseconds, not microseconds"
     that was done on the basis of spec typo (Bjorn Helgaas)
   - Rename pci_dev.d3_delay to d3hot_delay to remove D3hot/D3cold
     ambiguity (Krzysztof Wilczyński)
   - Remove unused pcibios_pm_ops (Vaibhav Gupta)

  IOMMU:
   - Enable Translation Blocking for external devices to harden against
     DMA attacks (Rajat Jain)

  Error handling:
   - Add an ACPI APEI notifier chain for vendor CPER records to enable
     device-specific error handling (Shiju Jose)

  ASPM:
   - Remove struct aspm_register_info to simplify code (Saheed O.
     Bolarinwa)

  Amlogic Meson PCIe controller driver:
   - Build as module by default (Kevin Hilman)

  Ampere Altra PCIe controller driver:
   - Add MCFG quirk to work around non-standard ECAM implementation
     (Tuan Phan)

  Broadcom iProc PCIe controller driver:
   - Set affinity mask on MSI interrupts (Mark Tomlinson)

  Broadcom STB PCIe controller driver:
   - Make PCIE_BRCMSTB depend on ARCH_BRCMSTB (Jim Quinlan)
   - Add DT bindings for more Brcmstb chips (Jim Quinlan)
   - Add bcm7278 register info (Jim Quinlan)
   - Add bcm7278 PERST# support (Jim Quinlan)
   - Add suspend and resume pm_ops (Jim Quinlan)
   - Add control of rescal reset (Jim Quinlan)
   - Set additional internal memory DMA viewport sizes (Jim Quinlan)
   - Accommodate MSI for older chips (Jim Quinlan)
   - Set bus max burst size by chip type (Jim Quinlan)
   - Add support for bcm7211, bcm7216, bcm7445, bcm7278 (Jim Quinlan)

  Freescale i.MX6 PCIe controller driver:
   - Use dev_err_probe() to reduce redundant messages (Anson Huang)

  Freescale Layerscape PCIe controller driver:
   - Enforce 4K DMA buffer alignment in endpoint test (Hou Zhiqiang)
   - Add DT compatible strings for ls1088a, ls2088a (Xiaowei Bao)
   - Add endpoint support for ls1088a, ls2088a (Xiaowei Bao)
   - Add endpoint test support for lS1088a (Xiaowei Bao)
   - Add MSI-X support for ls1088a (Xiaowei Bao)

  HiSilicon HIP PCIe controller driver:
   - Handle HIP-specific errors via ACPI APEI (Yicong Yang)

  HiSilicon Kirin PCIe controller driver:
   - Return -EPROBE_DEFER if the GPIO isn't ready (Bean Huo)

  Intel VMD host bridge driver:
   - Factor out physical offset, bus offset, IRQ domain, IRQ allocation
     (Jon Derrick)
   - Use generic PCI PM correctly (Jon Derrick)

  Marvell Aardvark PCIe controller driver:
   - Fix compilation on s390 (Pali Rohár)
   - Implement driver 'remove' function and allow to build it as module
     (Pali Rohár)
   - Move PCIe reset card code to advk_pcie_train_link() (Pali Rohár)
   - Convert mvebu a3700 internal SMCC firmware return codes to errno
     (Pali Rohár)
   - Fix initialization with old Marvell's Arm Trusted Firmware (Pali
     Rohár)

  Microsoft Hyper-V host bridge driver:
   - Fix hibernation in case interrupts are not re-created (Dexuan Cui)

  NVIDIA Tegra PCIe controller driver:
   - Stop checking return value of debugfs_create() functions (Greg
     Kroah-Hartman)
   - Convert to use DEFINE_SEQ_ATTRIBUTE macro (Liu Shixin)

  Qualcomm PCIe controller driver:
   - Reset PCIe to work around Qsdk U-Boot issue (Ansuel Smith)

  Renesas R-Car PCIe controller driver:
   - Add DT documentation for r8a774a1, r8a774b1, r8a774e1 endpoints
     (Lad Prabhakar)
   - Add RZ/G2M, RZ/G2N, RZ/G2H IDs to endpoint test (Lad Prabhakar)
   - Add DT support for r8a7742 (Lad Prabhakar)

  Socionext UniPhier Pro5 controller driver:
   - Add DT descriptions of iATU register (host and endpoint) (Kunihiko
     Hayashi)

  Synopsys DesignWare PCIe controller driver:
   - Add link up check in dw_child_pcie_ops.map_bus() (racy, but seems
     unavoidable) (Hou Zhiqiang)
   - Fix endpoint Header Type check so multi-function devices work (Hou
     Zhiqiang)
   - Skip PCIE_MSI_INTR0* programming if MSI is disabled (Jisheng Zhang)
   - Stop leaking MSI page in suspend/resume (Jisheng Zhang)
   - Add common iATU register support instead of keystone-specific code
     (Kunihiko Hayashi)
   - Major config space access and other cleanups in dwc core and
     drivers that use it (al, exynos, histb, imx6, intel-gw, keystone,
     kirin, meson, qcom, tegra) (Rob Herring)
   - Add multiple PFs support for endpoint (Xiaowei Bao)
   - Add MSI-X doorbell mode in endpoint mode (Xiaowei Bao)

  Miscellaneous:
   - Use fallthrough pseudo-keyword (Gustavo A. R. Silva)
   - Fix "0 used as NULL pointer" warnings (Gustavo Pimentel)
   - Fix "cast truncates bits from constant value" warnings (Gustavo
     Pimentel)
   - Remove redundant zeroing for sg_init_table() (Julia Lawall)
   - Use scnprintf(), not snprintf(), in sysfs "show" functions
     (Krzysztof Wilczyński)
   - Remove unused assignments (Krzysztof Wilczyński)
   - Fix "0 used as NULL pointer" warning (Krzysztof Wilczyński)
   - Simplify bool comparisons (Krzysztof Wilczyński)
   - Use for_each_child_of_node() and for_each_node_by_name() (Qinglang
     Miao)
   - Simplify return expressions (Qinglang Miao)"

* tag 'pci-v5.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (147 commits)
  PCI: vmd: Update VMD PM to correctly use generic PCI PM
  PCI: vmd: Create IRQ allocation helper
  PCI: vmd: Create IRQ Domain configuration helper
  PCI: vmd: Create bus offset configuration helper
  PCI: vmd: Create physical offset helper
  PCI: v3-semi: Remove unneeded break
  PCI: dwc: Add link up check in dw_child_pcie_ops.map_bus()
  PCI/ASPM: Remove struct pcie_link_state.l1ss
  PCI/ASPM: Remove struct aspm_register_info.l1ss_cap
  PCI/ASPM: Pass L1SS Capabilities value, not struct aspm_register_info
  PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl1
  PCI/ASPM: Remove struct aspm_register_info.l1ss_ctl2 (unused)
  PCI/ASPM: Remove struct aspm_register_info.l1ss_cap_ptr
  PCI/ASPM: Remove struct aspm_register_info.latency_encoding
  PCI/ASPM: Remove struct aspm_register_info.enabled
  PCI/ASPM: Remove struct aspm_register_info.support
  PCI/ASPM: Use 'parent' and 'child' for readability
  PCI/ASPM: Move LTR path check to where it's used
  PCI/ASPM: Move pci_clear_and_set_dword() earlier
  PCI: dwc: Fix MSI page leakage in suspend/resume
  ...
</content>
</entry>
<entry>
<title>Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux</title>
<updated>2020-10-14T17:32:10Z</updated>
<author>
<name>Linus Torvalds</name>
</author>
<published>2020-10-14T17:32:10Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=4907a43da83184d4e88009654c9b31f5e091f709'/>
<id>urn:sha1:4907a43da83184d4e88009654c9b31f5e091f709</id>
<content type='text'>
Pull Hyper-V updates from Wei Liu:

 - a series from Boqun Feng to support page size larger than 4K

 - a few miscellaneous clean-ups

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv: clocksource: Add notrace attribute to read_hv_sched_clock_*() functions
  x86/hyperv: Remove aliases with X64 in their name
  PCI: hv: Document missing hv_pci_protocol_negotiation() parameter
  scsi: storvsc: Support PAGE_SIZE larger than 4K
  Driver: hv: util: Use VMBUS_RING_SIZE() for ringbuffer sizes
  HID: hyperv: Use VMBUS_RING_SIZE() for ringbuffer sizes
  Input: hyperv-keyboard: Use VMBUS_RING_SIZE() for ringbuffer sizes
  hv_netvsc: Use HV_HYP_PAGE_SIZE for Hyper-V communication
  hv: hyperv.h: Introduce some hvpfn helper functions
  Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header
  Drivers: hv: Use HV_HYP_PAGE in hv_synic_enable_regs()
  Drivers: hv: vmbus: Introduce types of GPADL
  Drivers: hv: vmbus: Move __vmbus_open()
  Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl
  drivers: hv: remove cast from hyperv_die_event
</content>
</entry>
<entry>
<title>PCI: hv: Fix hibernation in case interrupts are not re-created</title>
<updated>2020-10-02T11:34:25Z</updated>
<author>
<name>Dexuan Cui</name>
</author>
<published>2020-10-02T08:51:58Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=915cff7f38c5e4d47f187f8049245afc2cb3e503'/>
<id>urn:sha1:915cff7f38c5e4d47f187f8049245afc2cb3e503</id>
<content type='text'>
pci_restore_msi_state() directly writes the MSI/MSI-X related registers
via MMIO. On a physical machine, this works perfectly; for a Linux VM
running on a hypervisor, which typically enables IOMMU interrupt remapping,
the hypervisor usually should trap and emulate the MMIO accesses in order
to re-create the necessary interrupt remapping table entries in the IOMMU,
otherwise the interrupts can not work in the VM after hibernation.

Hyper-V is different from other hypervisors in that it does not trap and
emulate the MMIO accesses, and instead it uses a para-virtualized method,
which requires the VM to call hv_compose_msi_msg() to notify the hypervisor
of the info that would be passed to the hypervisor in the case of the
trap-and-emulate method. This is not an issue to a lot of PCI device
drivers, which destroy and re-create the interrupts across hibernation, so
hv_compose_msi_msg() is called automatically. However, some PCI device
drivers (e.g. the in-tree GPU driver nouveau and the out-of-tree Nvidia
proprietary GPU driver) do not destroy and re-create MSI/MSI-X interrupts
across hibernation, so hv_pci_resume() has to call hv_compose_msi_msg(),
otherwise the PCI device drivers can no longer receive interrupts after
the VM resumes from hibernation.

Hyper-V is also different in that chip-&gt;irq_unmask() may fail in a
Linux VM running on Hyper-V (on a physical machine, chip-&gt;irq_unmask()
can not fail because unmasking an MSI/MSI-X register just means an MMIO
write): during hibernation, when a CPU is offlined, the kernel tries
to move the interrupt to the remaining CPUs that haven't been offlined
yet. In this case, hv_irq_unmask() -&gt; hv_do_hypercall() always fails
because the vmbus channel has been closed: here the early "return" in
hv_irq_unmask() means the pci_msi_unmask_irq() is not called, i.e. the
desc-&gt;masked remains "true", so later after hibernation, the MSI interrupt
always remains masked, which is incorrect. Refer to cpu_disable_common()
-&gt; fixup_irqs() -&gt; irq_migrate_all_off_this_cpu() -&gt; migrate_one_irq():

static bool migrate_one_irq(struct irq_desc *desc)
{
...
        if (maskchip &amp;&amp; chip-&gt;irq_mask)
                chip-&gt;irq_mask(d);
...
        err = irq_do_set_affinity(d, affinity, false);
...
        if (maskchip &amp;&amp; chip-&gt;irq_unmask)
                chip-&gt;irq_unmask(d);

Fix the issue by calling pci_msi_unmask_irq() unconditionally in
hv_irq_unmask(). Also suppress the error message for hibernation because
the hypercall failure during hibernation does not matter (at this time
all the devices have been frozen). Note: the correct affinity info is
still updated into the irqdata data structure in migrate_one_irq() -&gt;
irq_do_set_affinity() -&gt; hv_set_affinity(), so later when the VM
resumes, hv_pci_restore_msi_state() is able to correctly restore
the interrupt with the correct affinity.

Link: https://lore.kernel.org/r/20201002085158.9168-1-decui@microsoft.com
Fixes: ac82fc832708 ("PCI: hv: Add hibernation support")
Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Signed-off-by: Lorenzo Pieralisi &lt;lorenzo.pieralisi@arm.com&gt;
Reviewed-by: Jake Oshins &lt;jakeo@microsoft.com&gt;
</content>
</entry>
<entry>
<title>PCI: hv: Document missing hv_pci_protocol_negotiation() parameter</title>
<updated>2020-09-28T09:00:35Z</updated>
<author>
<name>Krzysztof Wilczyński</name>
</author>
<published>2020-09-25T23:47:53Z</published>
<link rel='alternate' type='text/html' href='https://git.0xinfinity.dev/distro/kernel.git/commit/?id=6d2730cb11214f492cbf381cef1758e15857bb69'/>
<id>urn:sha1:6d2730cb11214f492cbf381cef1758e15857bb69</id>
<content type='text'>
Add missing documentation for the parameter "version" and "num_version"
of the hv_pci_protocol_negotiation() function and resolve build time
kernel-doc warnings:

  drivers/pci/controller/pci-hyperv.c:2535: warning: Function parameter
  or member 'version' not described in 'hv_pci_protocol_negotiation'

  drivers/pci/controller/pci-hyperv.c:2535: warning: Function parameter
  or member 'num_version' not described in 'hv_pci_protocol_negotiation'

No change to functionality intended.

Signed-off-by: Krzysztof Wilczyński &lt;kw@linux.com&gt;
Link: https://lore.kernel.org/r/20200925234753.1767227-1-kw@linux.com
Reviewed-by: Michael Kelley &lt;mikelley@microsoft.com&gt;
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
</content>
</entry>
</feed>
