From: Laszlo Ersek <lersek@redhat.com>
Date: Sat, 12 Mar 2016 13:41:26 +0000 (+0100)
Subject: OvmfPkg: VirtioNetDxe: adapt feature negotiation to virtio-1.0
X-Git-Tag: edk2-stable201903~7412
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=33c6b934bf973bd3e0f72805ad723558cfffaa7f;hp=33c6b934bf973bd3e0f72805ad723558cfffaa7f;p=mirror_edk2.git

OvmfPkg: VirtioNetDxe: 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>
---