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| author | Laszlo Ersek <lersek@redhat.com> | 2016-08-18 13:52:26 +0200 |
|---|---|---|
| committer | Laszlo Ersek <lersek@redhat.com> | 2016-09-01 22:54:47 +0200 |
| commit | 76569ca855916d528fa7abd034e880e114d6d5cd (patch) | |
| tree | 489383f0a21cc2e5078b658c0aacb0256baad28c /OvmfPkg/Virtio10Dxe | |
| parent | 442c2ab81e87766f49a0f5656f39512bf1908028 (diff) | |
| download | edk2-platforms-76569ca855916d528fa7abd034e880e114d6d5cd.tar.xz | |
OvmfPkg/Virtio10Dxe: don't bind virtio-vga
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 <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://tianocore.acgmultimedia.com/show_bug.cgi?id=66
Fixes: 9399f68ae359234b142c293ad1bef75f470ced30
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Diffstat (limited to 'OvmfPkg/Virtio10Dxe')
| -rw-r--r-- | OvmfPkg/Virtio10Dxe/Virtio10.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/OvmfPkg/Virtio10Dxe/Virtio10.c b/OvmfPkg/Virtio10Dxe/Virtio10.c index 06f0699077..a8a6a58c3f 100644 --- a/OvmfPkg/Virtio10Dxe/Virtio10.c +++ b/OvmfPkg/Virtio10Dxe/Virtio10.c @@ -822,6 +822,7 @@ Virtio10BindingSupported ( 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.
@@ -832,9 +833,20 @@ Virtio10BindingSupported ( 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:
|