Ksawlii/kernel_samsung_a53x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

PCI: hv: Return zero, not garbage, when reading PCI_INTERRUPT_PIN

Browse source 
commit fea93a3e5d5e6a09eb153866d2ce60ea3287a70d upstream.

The intent of the code snippet is to always return 0 for both
PCI_INTERRUPT_LINE and PCI_INTERRUPT_PIN.

The check misses PCI_INTERRUPT_PIN. This patch fixes that.

This is discovered by this call in VFIO:

    pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);

The old code does not set *val to 0 because it misses the check for
PCI_INTERRUPT_PIN. Garbage is returned in that case.

Fixes: 4daace0d8ce8 ("PCI: hv: Add paravirtual PCI front-end for Microsoft Hyper-V VMs")
Link: https://lore.kernel.org/linux-pci/20240701202606.129606-1-wei.liu@kernel.org
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Wei Liu 2024-07-01 20:26:05 +00:00 • committed by Ksawlii
parent 0e3ad906db
commit 7f8bb7581b
1 changed files with 2 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
drivers/pci/controller/pci-hyperv.c
View file

@ -680,8 +680,8 @@ static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where,
PCI_CAPABILITY_LIST) {
/* ROM BARs are unimplemented */
*val = 0;
} else if (where >= PCI_INTERRUPT_LINE && where + size <=
PCI_INTERRUPT_PIN) {
} else if ((where >= PCI_INTERRUPT_LINE && where + size <= PCI_INTERRUPT_PIN) ||
(where >= PCI_INTERRUPT_PIN && where + size <= PCI_MIN_GNT)) {
/*
* Interrupt Line and Interrupt PIN are hard-wired to zero
* because this front-end only supports message-signaled