[PATCH v3 0/6] pci-hyper: Fix race condition bugs for fast device hotplug

From: Dexuan Cui
Date: Wed Apr 19 2023 - 22:41:18 EST


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 removes the use of a global mutex lock, and enables async-probing
to allow concurrent device probing for faster boot.

v3 is based on v6.3-rc5. No code change since v2. I just added Michael's
and Long Li's Reviewed-by.

The patchset is also availsble in my github branch:
https://github.com/dcui/tdx/commits/decui/vpci/v6.3-rc5-v3

v2 can be found here:
https://lwn.net/ml/linux-kernel/20230404020545.32359-1-decui@xxxxxxxxxxxxx/

Please review. Thanks!


Dexuan Cui (6):
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
PCI: hv: Use async probing to reduce boot time

drivers/pci/controller/pci-hyperv.c | 145 +++++++++++++++++-----------
1 file changed, 86 insertions(+), 59 deletions(-)

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2.25.1