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> --- OvmfPkg/VirtioBlkDxe/VirtioBlk.c | 25 ++++++++++++++++---- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c index 8257effac22d..f1c3f87e2027 100644 --- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c +++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c @@ -688,14 +688,28 @@ VirtioBlkInit ( Status = VIRTIO_CFG_READ (Dev, Topology.OptIoSize, &OptIoSize); if (EFI_ERROR (Status)) { goto Failed; } } + Features &= VIRTIO_BLK_F_BLK_SIZE | VIRTIO_BLK_F_TOPOLOGY | VIRTIO_BLK_F_RO | + VIRTIO_BLK_F_FLUSH | 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 Failed; + } + } + // // step 4b -- allocate virtqueue // Status = Dev->VirtIo->SetQueueSel (Dev->VirtIo, 0); if (EFI_ERROR (Status)) { goto Failed; } @@ -735,19 +749,20 @@ VirtioBlkInit ( goto ReleaseQueue; } // // step 5 -- Report understood features. // - Features &= VIRTIO_BLK_F_BLK_SIZE | VIRTIO_BLK_F_TOPOLOGY | VIRTIO_BLK_F_RO | - VIRTIO_BLK_F_FLUSH; - Status = Dev->VirtIo->SetGuestFeatures (Dev->VirtIo, Features); - if (EFI_ERROR (Status)) { - goto ReleaseQueue; + 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 ReleaseQueue; + } } // // step 6 -- 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