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authorLaszlo Ersek <lersek@redhat.com>2016-03-12 14:41:26 +0100
committerLaszlo Ersek <lersek@redhat.com>2016-04-06 19:21:50 +0200
commitcbad8e4cccf61c91932e7f091f9144448871c968 (patch)
tree93bc419c437688bd91b17ea84b8738d8fd352be0 /OvmfPkg
parentd0ece0d85050022f96f31291e2f0033ebcdb3c6f (diff)
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edk2-cbad8e4cccf61c91932e7f091f9144448871c968.tar.bz2
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OvmfPkg: VirtioBlkDxe: adapt feature negotiation to virtio-1.0
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>
Diffstat (limited to 'OvmfPkg')
-rw-r--r--OvmfPkg/VirtioBlkDxe/VirtioBlk.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
index 8257effac2..f1c3f87e20 100644
--- a/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
+++ b/OvmfPkg/VirtioBlkDxe/VirtioBlk.c
@@ -692,6 +692,20 @@ VirtioBlkInit (
}
}
+ 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
//
@@ -739,11 +753,12 @@ VirtioBlkInit (
//
// 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;
+ }
}
//