[PATCH 0/4] PCI/CXL: Guard reset recovery against inaccessible devices

[Richard Cheng <icheng@nvidia.com>]

During FLR testing, PCI configuration reads returned all ones. The
kernel could mistake this for reset completion and proceed with MSI-X
restoration. The resulting MMIO access triggered DPC containment.

This series addresses four issues:

1. Reject all-ones responses in pci_dev_wait(). Use Command-register
    polling for VFs, whose Vendor ID legitimately reads as all ones.

2. Return -ETIMEDOUT when readiness polling expires, preventing fallback
    to another reset method.

3. Check configuration accessibility before restoring PCI state, while
    preserving driver reset callbacks.

4. Skip CXL decoder MMIO accesses when configuration is inaccessible
    or memory decoding is disabled.


Best regards,
Richard Cheng.

Richard Cheng (4):
  PCI: Reject all-ones responses in pci_dev_wait()
  PCI: Return -ETIMEOUT when reset readiness polling expires
  PCI: Skip state restoration when configuration is inaccessible
  cxl/pci: Guard decoder accesses after reset

 drivers/cxl/pci.c |  6 ++++++
 drivers/pci/pci.c | 16 +++++++++-------
 2 files changed, 15 insertions(+), 7 deletions(-)


base-commit: 9eb6419022d81aac6d1d9ead0e1865b451153da5
-- 
2.43.0