From f2bc54de47404b70b9ac87e2c75489f2652643e7 Mon Sep 17 00:00:00 2001 From: Ladi Prosek Date: Mon, 13 Nov 2017 09:45:58 +0100 Subject: [PATCH] virtio-pci: Don't force Subsystem Vendor ID = Vendor ID 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 Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Gerd Hoffmann --- hw/virtio/virtio-pci.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 42b31fbcf8..6c75cca88a 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 */ -- 2.11.4.GIT