Commit 9399f68ae359 ("OvmfPkg: Virtio10Dxe: non-transitional driver for
virtio-1.0 PCI devices") created a "competition" between Virtio10Dxe and
QemuVideoDxe for virtio-vga devices. The binding order between these
drivers is unspecified, and the wrong order effectively breaks commit
94210dc95e9f ("OvmfPkg: QemuVideoDxe: add virtio-vga support").Thus, never bind virtio-vga in Virtio10Dxe; QemuVideoDxe provides better compatibility for guest OSes that insist on inheriting a linear framebuffer. Users who prefer the VirtIo GPU interface at boot time should specify virtio-gpu-pci, which is exactly virtio-vga, minus the VGA compatibility (such as the framebuffer). Cc: Ard Biesheuvel <[email protected]> Cc: Jordan Justen <[email protected]> Ref: https://tianocore.acgmultimedia.com/show_bug.cgi?id=66 Fixes: 9399f68ae359234b142c293ad1bef75f470ced30 Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <[email protected]> --- OvmfPkg/Virtio10Dxe/Virtio10.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/OvmfPkg/Virtio10Dxe/Virtio10.c b/OvmfPkg/Virtio10Dxe/Virtio10.c index 06f069907753..a8a6a58c3f1d 100644 --- a/OvmfPkg/Virtio10Dxe/Virtio10.c +++ b/OvmfPkg/Virtio10Dxe/Virtio10.c @@ -819,25 +819,37 @@ Virtio10BindingSupported ( Status = PciIo->Pci.Read (PciIo, EfiPciIoWidthUint32, 0, sizeof Pci / sizeof (UINT32), &Pci); if (EFI_ERROR (Status)) { goto CloseProtocol; } + Status = EFI_UNSUPPORTED; // // Recognize non-transitional modern devices. Also, we'll have to parse the // PCI capability list, so make sure the CapabilityPtr field will be valid. // if (Pci.Hdr.VendorId == VIRTIO_VENDOR_ID && Pci.Hdr.DeviceId >= 0x1040 && Pci.Hdr.DeviceId <= 0x107F && Pci.Hdr.RevisionID >= 0x01 && Pci.Device.SubsystemID >= 0x40 && (Pci.Hdr.Status & EFI_PCI_STATUS_CAPABILITY) != 0) { - Status = EFI_SUCCESS; - } else { - Status = EFI_UNSUPPORTED; + // + // The virtio-vga device is special. It can be driven both as a VGA device + // with a linear framebuffer, and through its underlying, modern, + // virtio-gpu-pci device, which has no linear framebuffer itself. For + // compatibility with guest OSes that insist on inheriting a linear + // framebuffer from the firmware, we should leave virtio-vga to + // QemuVideoDxe, and support only virtio-gpu-pci here. + // + // Both virtio-vga and virtio-gpu-pci have DeviceId 0x1050, but only the + // former has device class PCI_CLASS_DISPLAY_VGA. + // + if (Pci.Hdr.DeviceId != 0x1050 || !IS_PCI_VGA (&Pci)) { + Status = EFI_SUCCESS; + } } CloseProtocol: gBS->CloseProtocol (DeviceHandle, &gEfiPciIoProtocolGuid, This->DriverBindingHandle, DeviceHandle); -- 2.9.2 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
