Alex Williamson <[email protected]> writes: > If the PCI core set cfg_size isn't large enough for extended > capabilities, then they're not there. Extended config space may be > inaccessible due to a PCI bridge, in which case cfg_size may be cut > short.
Just curious, is this part of the spec or just a convention ? I mean could there be devices with quirks ? > Signed-off-by: Alex Williamson <[email protected]> > --- > drivers/vfio/pci/vfio_pci_config.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/vfio/pci/vfio_pci_config.c > b/drivers/vfio/pci/vfio_pci_config.c > index 83cd157..4a62a37 100644 > --- a/drivers/vfio/pci/vfio_pci_config.c > +++ b/drivers/vfio/pci/vfio_pci_config.c > @@ -1027,8 +1027,11 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, > u8 cap, u8 pos) > > if (PCI_X_CMD_VERSION(word)) { > /* Test for extended capabilities */ > - pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword); > - vdev->extended_caps = (dword != 0); > + if (pdev->cfg_size > PCI_CFG_SPACE_SIZE) { > + pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, > + &dword); > + vdev->extended_caps = (dword != 0); > + } > return PCI_CAP_PCIX_SIZEOF_V2; > } else > return PCI_CAP_PCIX_SIZEOF_V0; > @@ -1041,8 +1044,10 @@ static int vfio_cap_len(struct vfio_pci_device *vdev, > u8 cap, u8 pos) > return byte; > case PCI_CAP_ID_EXP: > /* Test for extended capabilities */ > - pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword); > - vdev->extended_caps = (dword != 0); > + if (pdev->cfg_size > PCI_CFG_SPACE_SIZE) { > + pci_read_config_dword(pdev, PCI_CFG_SPACE_SIZE, &dword); > + vdev->extended_caps = (dword != 0); > + } > > /* length based on version */ > if ((pcie_caps_reg(pdev) & PCI_EXP_FLAGS_VERS) == 1) > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
