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| author | Wei Liu <wei.liu@kernel.org> | 2024-07-01 20:26:05 +0000 |
|---|---|---|
| committer | Krzysztof Wilczyński <kwilczynski@kernel.org> | 2024-07-03 21:11:14 +0000 |
| commit | fea93a3e5d5e6a09eb153866d2ce60ea3287a70d (patch) | |
| tree | f40a4ae5808738194eb31902d2f8360a483bc0a6 /drivers/pci | |
| parent | 1613e604df0cd359cf2a7fbd9be7a0bcfacfabd0 (diff) | |
| download | lwn-fea93a3e5d5e6a09eb153866d2ce60ea3287a70d.tar.gz lwn-fea93a3e5d5e6a09eb153866d2ce60ea3287a70d.zip | |
PCI: hv: Return zero, not garbage, when reading PCI_INTERRUPT_PIN
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
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 5992280e8110..cdd5be16021d 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -1130,8 +1130,8 @@ 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 |