PCI: hv: Warn when wait_for_response() waits indefinitely

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A guest can wait indefinitely in wait_for_response() for the host to
send either a rescind message or a packet completion. If the
host does not send either, the guest can remain blocked with no
diagnostic indicating a reason.
This was observed during a guest kernel upgrade in which the
host-side application handling the PCI channel faulted, causing the
guest to never receive the completion request.
Add a warning in wait_for_response() when the wait exceeds
a timeout so that such a hang is visible in the guest's kernel log
and can be correlated with host-side state.

Suggested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Sahil Chandna <sahilchandna@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

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Sahil Chandna 2026-09-14 03:39:09 -07:00 • committed by Wei Liu

parent c37fc4deee

commit ca039df949

1 changed files with 36 additions and 10 deletions

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drivers/pci/controller/pci-hyperv.c

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