diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2019-10-23 11:04:11 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2019-10-25 07:46:22 -0400 |
| commit | 60ce3a40fc18423d6c3ba330e60ca03fc74f9d21 (patch) | |
| tree | 93d69a8591910aa1a947f050f7533c32572c43c8 /tests/libqos/virtio.c | |
| parent | c42bf5f21043c86d50773220998b54ded091f779 (diff) | |
libqos: read QVIRTIO_MMIO_VERSION register
There was no real virtio-mmio ABI change between Legacy and VIRTIO 1.0
except that the Version field was incremented from 1 to 2.
However, QEMU does not allow Legacy drivers to perform VIRTIO 1.0
operations like accessing 64-bit feature bits. Since we will introduce
64-bit feature bit support we need a way to differentiate between
virtio-mmio Version 1 and 2 to avoid upsetting QEMU when we operate in
Legacy mode.
Stash away the Version field so later patches can change behavior
depending on the version.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20191023100425.12168-3-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'tests/libqos/virtio.c')
0 files changed, 0 insertions, 0 deletions