vfio/pci: Allow VPD short read
The size of the VPD area is not necessarily 4-byte aligned, so a
pci_vpd_read() might return less than 4 bytes. Zero our buffer and
accept anything other than an error. Intel X710 NICs exercise this.
Fixes: 4e1a635552d3 ("vfio/pci: Use kernel VPD access functions")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 9360140..688691d 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -749,7 +749,8 @@
if (pci_write_vpd(pdev, addr & ~PCI_VPD_ADDR_F, 4, &data) != 4)
return count;
} else {
- if (pci_read_vpd(pdev, addr, 4, &data) != 4)
+ data = 0;
+ if (pci_read_vpd(pdev, addr, 4, &data) < 0)
return count;
*pdata = cpu_to_le32(data);
}