| Message ID | 20171113084558.28369-1-lprosek@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Nov 13, 2017 at 09:45:58AM +0100, Ladi Prosek wrote: > The statement being removed doesn't change anything as virtio PCI devices already > have Subsystem Vendor ID set to pci_default_sub_vendor_id (0x1af4), same as Vendor > ID. And the Virtio spec does not require the two to be equal, either: > > "The PCI Subsystem Vendor ID and the PCI Subsystem Device ID MAY reflect the PCI > Vendor and Device ID of the environment (for informational purposes by the driver)." > > Background: > > Following the recent virtio-win licensing change, several vendors are planning to > ship their own certified version of Windows guest Virtio drivers, potentially taking > advantage of Windows Update as a distribution channel. It is therefore critical that > each vendor uses their own PCI Subsystem Vendor ID for Virtio devices to prevent > drivers from other vendors binding to it. > > This would be trivially done by adding: > > k->subsystem_vendor_id = ... > > to virtio_pci_class_init(). Except for the problematic statement deleted by this > patch, which reverts the Subsystem Vendor ID back to 0x1af4 for legacy devices for > no good reason. Reviewed-by: Gerd Hoffmann <kraxel@redhat.com> cheers, Gerd
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index e92837c42b..148621d9c7 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -1588,9 +1588,11 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp) "neither legacy nor transitional device."); return ; } - /* legacy and transitional */ - pci_set_word(config + PCI_SUBSYSTEM_VENDOR_ID, - pci_get_word(config + PCI_VENDOR_ID)); + /* + * Legacy and transitional devices use specific subsystem IDs. + * Note that the subsystem vendor ID (config + PCI_SUBSYSTEM_VENDOR_ID) + * is set to PCI_SUBVENDOR_ID_REDHAT_QUMRANET by default. + */ pci_set_word(config + PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus)); } else { /* pure virtio-1.0 */
The statement being removed doesn't change anything as virtio PCI devices already have Subsystem Vendor ID set to pci_default_sub_vendor_id (0x1af4), same as Vendor ID. And the Virtio spec does not require the two to be equal, either: "The PCI Subsystem Vendor ID and the PCI Subsystem Device ID MAY reflect the PCI Vendor and Device ID of the environment (for informational purposes by the driver)." Background: Following the recent virtio-win licensing change, several vendors are planning to ship their own certified version of Windows guest Virtio drivers, potentially taking advantage of Windows Update as a distribution channel. It is therefore critical that each vendor uses their own PCI Subsystem Vendor ID for Virtio devices to prevent drivers from other vendors binding to it. This would be trivially done by adding: k->subsystem_vendor_id = ... to virtio_pci_class_init(). Except for the problematic statement deleted by this patch, which reverts the Subsystem Vendor ID back to 0x1af4 for legacy devices for no good reason. Signed-off-by: Ladi Prosek <lprosek@redhat.com> --- v1->v2: * Added a comment about the default Subsystem Vendor ID. hw/virtio/virtio-pci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)