diff options
| -rw-r--r-- | hw/vfio/pci.c | 49 | ||||
| -rw-r--r-- | hw/vfio/trace-events | 1 |
2 files changed, 40 insertions, 10 deletions
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c index a171056b41..f2c679e47c 100644 --- a/hw/vfio/pci.c +++ b/hw/vfio/pci.c @@ -1772,6 +1772,12 @@ static int vfio_add_ext_cap(VFIOPCIDevice *vdev) uint8_t cap_ver; uint8_t *config; + /* Only add extended caps if we have them and the guest can see them */ + if (!pci_is_express(pdev) || !pci_bus_is_express(pdev->bus) || + !pci_get_long(pdev->config + PCI_CONFIG_SPACE_SIZE)) { + return 0; + } + /* * pcie_add_capability always inserts the new capability at the tail * of the chain. Therefore to end up with a chain that matches the @@ -1780,6 +1786,25 @@ static int vfio_add_ext_cap(VFIOPCIDevice *vdev) */ config = g_memdup(pdev->config, vdev->config_size); + /* + * Extended capabilities are chained with each pointing to the next, so we + * can drop anything other than the head of the chain simply by modifying + * the previous next pointer. For the head of the chain, we can modify the + * capability ID to something that cannot match a valid capability. ID + * 0 is reserved for this since absence of capabilities is indicated by + * 0 for the ID, version, AND next pointer. However, pcie_add_capability() + * uses ID 0 as reserved for list management and will incorrectly match and + * assert if we attempt to pre-load the head of the chain with with this + * ID. Use ID 0xFFFF temporarily since it is also seems to be reserved in + * part for identifying absence of capabilities in a root complex register + * block. If the ID still exists after adding capabilities, switch back to + * zero. We'll mark this entire first dword as emulated for this purpose. + */ + pci_set_long(pdev->config + PCI_CONFIG_SPACE_SIZE, + PCI_EXT_CAP(0xFFFF, 0, 0)); + pci_set_long(pdev->wmask + PCI_CONFIG_SPACE_SIZE, 0); + pci_set_long(vdev->emulated_config_bits + PCI_CONFIG_SPACE_SIZE, ~0); + for (next = PCI_CONFIG_SPACE_SIZE; next; next = PCI_EXT_CAP_NEXT(pci_get_long(config + next))) { header = pci_get_long(config + next); @@ -1794,12 +1819,23 @@ static int vfio_add_ext_cap(VFIOPCIDevice *vdev) */ size = vfio_ext_cap_max_size(config, next); - pcie_add_capability(pdev, cap_id, cap_ver, next, size); - pci_set_long(pdev->config + next, PCI_EXT_CAP(cap_id, cap_ver, 0)); - /* Use emulated next pointer to allow dropping extended caps */ pci_long_test_and_set_mask(vdev->emulated_config_bits + next, PCI_EXT_CAP_NEXT_MASK); + + switch (cap_id) { + case PCI_EXT_CAP_ID_SRIOV: /* Read-only VF BARs confuse OVMF */ + trace_vfio_add_ext_cap_dropped(vdev->vbasedev.name, cap_id, next); + break; + default: + pcie_add_capability(pdev, cap_id, cap_ver, next, size); + } + + } + + /* Cleanup chain head ID if necessary */ + if (pci_get_word(pdev->config + PCI_CONFIG_SPACE_SIZE) == 0xFFFF) { + pci_set_word(pdev->config + PCI_CONFIG_SPACE_SIZE, 0); } g_free(config); @@ -1821,13 +1857,6 @@ static int vfio_add_capabilities(VFIOPCIDevice *vdev) return ret; } - /* on PCI bus, it doesn't make sense to expose extended capabilities. */ - if (!pci_is_express(pdev) || - !pci_bus_is_express(pdev->bus) || - !pci_get_long(pdev->config + PCI_CONFIG_SPACE_SIZE)) { - return 0; - } - return vfio_add_ext_cap(vdev); } diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events index 9da0ff928b..a768fb54ec 100644 --- a/hw/vfio/trace-events +++ b/hw/vfio/trace-events @@ -37,6 +37,7 @@ vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot reset: % vfio_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s config:\n size: 0x%lx, offset: 0x%lx, flags: 0x%lx" vfio_populate_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO failure: %m" vfio_initfn(const char *name, int group_id) " (%s) group %d" +vfio_add_ext_cap_dropped(const char *name, uint16_t cap, uint16_t offset) "%s %x@%x" vfio_pci_reset(const char *name) " (%s)" vfio_pci_reset_flr(const char *name) "%s FLR/VFIO_DEVICE_RESET" vfio_pci_reset_pm(const char *name) "%s PCI PM Reset" |