Relative to virtio-0.9.5, virtio-1.0 reverses the order of queue discovery
and feature negotiation. In virtio-1.0, feature negotiation has to
complete first, and the device can also reject a self-inconsistent feature
request through the new VSTAT_FEATURES_OK status bit. (For example if the
driver requests a higher level feature but clears a prerequisite feature.)
Furthermore, we retain the VIRTIO_F_VERSION_1 feature bit if the
VIRTIO_DEVICE_PROTOCOL provider has high enough revision.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
ASSERT (Dev->Snm.MediaPresentSupported ==\r
!!(Features & VIRTIO_NET_F_STATUS));\r
\r
ASSERT (Dev->Snm.MediaPresentSupported ==\r
!!(Features & VIRTIO_NET_F_STATUS));\r
\r
+ Features &= VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS | VIRTIO_F_VERSION_1;\r
+\r
+ //\r
+ // In virtio-1.0, feature negotiation is expected to complete before queue\r
+ // discovery, and the device can also reject the selected set of features.\r
+ //\r
+ if (Dev->VirtIo->Revision >= VIRTIO_SPEC_REVISION (1, 0, 0)) {\r
+ Status = Virtio10WriteFeatures (Dev->VirtIo, Features, &NextDevStat);\r
+ if (EFI_ERROR (Status)) {\r
+ goto DeviceFailed;\r
+ }\r
+ }\r
+\r
//\r
// step 4b, 4c -- allocate and report virtqueues\r
//\r
//\r
// step 4b, 4c -- allocate and report virtqueues\r
//\r
//\r
// step 5 -- keep only the features we want\r
//\r
//\r
// step 5 -- keep only the features we want\r
//\r
- Features &= VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS;\r
- Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features);\r
- if (EFI_ERROR (Status)) {\r
- goto ReleaseTxRing;\r
+ if (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) {\r
+ Features &= ~(UINT64)VIRTIO_F_VERSION_1;\r
+ Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features);\r
+ if (EFI_ERROR (Status)) {\r
+ goto ReleaseTxRing;\r
+ }\r