Subject: [PATCH v4 0/5] pci-hyperv: Fix race condition bugs for fast device hotplug

From: Dexuan Cui <[email-masked]>
Date: Wed, 14 Jun 2023 21:44:46 -0700

Before the guest finishes probing a device, the host may be already starting
to remove the device. Currently there are multiple race condition bugs in the
pci-hyperv driver, which can cause the guest to panic.  The patchset fixes
the crashes.

The patchset also does some cleanup work: patch 3 removes the useless
hv_pcichild_state, and patch 4 reverts an old patch which is not really
useful (without patch 4, it would be hard to make patch 5 clean).

Patch 6 in v3 is dropped for now since it's a feature rather than a fix.
Patch 6 will be split into two patches as suggested by Lorenzo and will be
posted after the 5 patches are accepted first.

The v4 addressed Lorenzo's comments and added Lorenzo' Acks to patch
1, 3 and 5.

The v4 is based on v6.4-rc6, and can apply cleanly to the Hyper-V tree's
hyperv-fixes branch.

The patchset is also availsble in my github branch:
https://github.com/dcui/tdx/commits/decui/vpci/v6.4-rc6-vpci-v4

FYI, v3 can be found here:
https://lwn.net/ml/linux-kernel/[email-masked]/

Please review. Thanks!

Dexuan Cui (5):
  PCI: hv: Fix a race condition bug in hv_pci_query_relations()
  PCI: hv: Fix a race condition in hv_irq_unmask() that can cause panic
  PCI: hv: Remove the useless hv_pcichild_state from struct hv_pci_dev
  Revert "PCI: hv: Fix a timing issue which causes kdump to fail
    occasionally"
  PCI: hv: Add a per-bus mutex state_lock

 drivers/pci/controller/pci-hyperv.c | 139 ++++++++++++++++------------
 1 file changed, 82 insertions(+), 57 deletions(-)

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2.25.1