From 27600805e62f800bacf990354632eae4e487d34c Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Thu, 3 Sep 2026 10:43:25 -0500 Subject: x86/amd_node: Fix PCI device reference counting in amd_smn_init() The local "root" pointer is a temporary variable used during the device search. Therefore, refcount related to the search iterators should be cleaned up after the search is complete. Use the __free() cleanup macro to ensure the refcount is decremented when the temporary pointer goes out of scope. Additionally, increment the refcount when caching a root pointer. This ensures the in-use refcount is separate from the temporary search refcounting. Finally, drop the redundant "root = NULL" before the second search loop. The pci_get_class() iterator always decrements the refcount of its "from" argument, so the first loop can only fall through with "root" already NULL. Fixes: 0a4b61d9c2e4 ("x86/amd_node: Fix AMD root device caching") Closes: https://sashiko.dev/#/patchset/20260806160159.230453-1-jason.andryuk%40amd.com Reported-by: Sashiko Assisted-by: LLM Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Mario Limonciello (AMD) Cc: Link: https://patch.msgid.link/20260903154325.74343-1-yazen.ghannam@amd.com --- Documentation/ABI/testing/sysfs-driver-pciback | 28 ++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-driver-pciback (limited to 'Documentation/ABI/testing/sysfs-driver-pciback') diff --git a/Documentation/ABI/testing/sysfs-driver-pciback b/Documentation/ABI/testing/sysfs-driver-pciback new file mode 100644 index 000000000..49f5fd0c8 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-pciback @@ -0,0 +1,28 @@ +What: /sys/bus/pci/drivers/pciback/quirks +Date: Oct 2011 +KernelVersion: 3.1 +Contact: xen-devel@lists.xenproject.org +Description: + If the permissive attribute is set, then writing a string in + the format of DDDD:BB:DD.F-REG:SIZE:MASK will allow the guest + to write and read from the PCI device. That is Domain:Bus: + Device.Function-Register:Size:Mask (Domain is optional). + For example:: + + #echo 00:19.0-E0:2:FF > /sys/bus/pci/drivers/pciback/quirks + + will allow the guest to read and write to the configuration + register 0x0E. + +What: /sys/bus/pci/drivers/pciback/allow_interrupt_control +Date: Jan 2020 +KernelVersion: 5.6 +Contact: xen-devel@lists.xenproject.org +Description: + List of devices which can have interrupt control flag (INTx, + MSI, MSI-X) set by a connected guest. It is meant to be set + only when the guest is a stubdomain hosting device model (qemu) + and the actual device is assigned to a HVM. It is not safe + (similar to permissive attribute) to set for a devices assigned + to a PV guest. The device is automatically removed from this + list when the connected pcifront terminates. -- cgit v1.3.1