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| author | Laszlo Ersek <lersek@redhat.com> | 2016-03-12 14:41:26 +0100 |
|---|---|---|
| committer | Laszlo Ersek <lersek@redhat.com> | 2016-04-06 19:21:50 +0200 |
| commit | 0a781bdc7f87f87b8c3ef57c2837f116daa8b580 (patch) | |
| tree | ad1e94bd73016052a3480a32f145b0799e02ddcf /OvmfPkg/VirtioRngDxe | |
| parent | 33c6b934bf973bd3e0f72805ad723558cfffaa7f (diff) | |
| download | edk2-0a781bdc7f87f87b8c3ef57c2837f116daa8b580.tar.gz edk2-0a781bdc7f87f87b8c3ef57c2837f116daa8b580.tar.bz2 edk2-0a781bdc7f87f87b8c3ef57c2837f116daa8b580.zip | |
OvmfPkg: VirtioRngDxe: 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/VirtioRngDxe')
| -rw-r--r-- | OvmfPkg/VirtioRngDxe/VirtioRng.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c index d916534aac..1a186d0408 100644 --- a/OvmfPkg/VirtioRngDxe/VirtioRng.c +++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c @@ -242,6 +242,19 @@ VirtioRngInit ( goto Failed;
}
+ Features &= 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 request virtqueue, just use #0
//
@@ -290,14 +303,14 @@ VirtioRngInit ( }
//
- // step 5 -- Report understood features and guest-tuneables. None are
- // currently defined for VirtioRng, and no generic features are needed by
- // this driver.
+ // step 5 -- Report understood features and guest-tuneables.
//
- Features &= 0;
- 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;
+ }
}
//
|