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.biesheu...@linaro.org> Cc: Jordan Justen <jordan.l.jus...@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <ler...@redhat.com> Tested-by: Ard Biesheuvel <ard.biesheu...@linaro.org> Reviewed-by: Jordan Justen <jordan.l.jus...@intel.com> --- OvmfPkg/VirtioNetDxe/SnpInitialize.c | 23 ++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/OvmfPkg/VirtioNetDxe/SnpInitialize.c b/OvmfPkg/VirtioNetDxe/SnpInitialize.c index f06b0a5a5742..38012a0df8d6 100644 --- a/OvmfPkg/VirtioNetDxe/SnpInitialize.c +++ b/OvmfPkg/VirtioNetDxe/SnpInitialize.c @@ -413,14 +413,27 @@ VirtioNetInitialize ( goto DeviceFailed; } ASSERT (Features & VIRTIO_NET_F_MAC); ASSERT (Dev->Snm.MediaPresentSupported == !!(Features & VIRTIO_NET_F_STATUS)); + Features &= VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS | VIRTIO_F_VERSION_1; + + // + // In virtio-1.0, feature negotiation is expected to complete before queue + // discovery, and the device can also reject the selected set of features. + // + if (Dev->VirtIo->Revision >= VIRTIO_SPEC_REVISION (1, 0, 0)) { + Status = Virtio10WriteFeatures (Dev->VirtIo, Features, &NextDevStat); + if (EFI_ERROR (Status)) { + goto DeviceFailed; + } + } + // // step 4b, 4c -- allocate and report virtqueues // Status = VirtioNetInitRing (Dev, VIRTIO_NET_Q_RX, &Dev->RxRing); if (EFI_ERROR (Status)) { goto DeviceFailed; } @@ -429,18 +442,20 @@ VirtioNetInitialize ( if (EFI_ERROR (Status)) { goto ReleaseRxRing; } // // step 5 -- keep only the features we want // - Features &= VIRTIO_NET_F_MAC | VIRTIO_NET_F_STATUS; - Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features); - if (EFI_ERROR (Status)) { - goto ReleaseTxRing; + if (Dev->VirtIo->Revision < VIRTIO_SPEC_REVISION (1, 0, 0)) { + Features &= ~(UINT64)VIRTIO_F_VERSION_1; + Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features); + if (EFI_ERROR (Status)) { + goto ReleaseTxRing; + } } // // step 6 -- virtio-net initialization complete // NextDevStat |= VSTAT_DRIVER_OK; Status = Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, NextDevStat); -- 1.8.3.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel