vfio/pci: Add virtual capabilities quirk infrastructure

If the hypervisor needs to add purely virtual capabilties, give us a
hook through quirks to do that.  Note that we determine the maximum
size for a capability based on the physical device, if we insert a
virtual capability, that can change.  Therefore if maximum size is
smaller after added virt capabilities, use that.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 916d365dfa..bfeaaef22d 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1833,8 +1833,16 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos, Error **errp)
         pdev->config[PCI_CAPABILITY_LIST] = 0;
         vdev->emulated_config_bits[PCI_CAPABILITY_LIST] = 0xff;
         vdev->emulated_config_bits[PCI_STATUS] |= PCI_STATUS_CAP_LIST;
+
+        ret = vfio_add_virt_caps(vdev, errp);
+        if (ret) {
+            return ret;
+        }
     }
 
+    /* Scale down size, esp in case virt caps were added above */
+    size = MIN(size, vfio_std_cap_max_size(pdev, pos));
+
     /* Use emulated next pointer to allow dropping caps */
     pci_set_byte(vdev->emulated_config_bits + pos + PCI_CAP_LIST_NEXT, 0xff);