From ce7585f3c4d76bca1dff4b66ae1ea32552954f9e Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Tue, 31 May 2016 21:25:52 -0600 Subject: [PATCH] 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 --- drivers/vfio/pci/vfio_pci_config.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) 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 @@ static int vfio_vpd_config_write(struct vfio_pci_device *vdev, int pos, 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); } -- 2.7.4