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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2020-05-29 17:13:38 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-06-12 10:17:06 -0400 |
| commit | a9a5c473d25d83bcdad27d97e5fb451950ee894a (patch) | |
| tree | d0e7564428aa96c3a3075a875afd3b03dd00e8dd /contrib | |
| parent | b650d5f4b1cd3f9f8c4fdb319838c5c1e0695e41 (diff) | |
| download | qemu-a9a5c473d25d83bcdad27d97e5fb451950ee894a.zip qemu-a9a5c473d25d83bcdad27d97e5fb451950ee894a.tar.gz qemu-a9a5c473d25d83bcdad27d97e5fb451950ee894a.tar.bz2 | |
libvhost-user: advertise vring features
libvhost-user implements several vring features without advertising
them. There is no way for the vhost-user master to detect support for
these features.
Things more or less work today because QEMU assumes the vhost-user
backend always implements certain feature bits like
VIRTIO_RING_F_EVENT_IDX. This is not documented anywhere.
This patch explicitly advertises features implemented in libvhost-user
so that the vhost-user master does not need to make undocumented
assumptions.
Feature bits that libvhost-user now advertises can be removed from
vhost-user-blk.c. Devices should not be responsible for advertising
vring feature bits, that is libvhost-user's job.
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200529161338.456017-1-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Diffstat (limited to 'contrib')
| -rw-r--r-- | contrib/libvhost-user/libvhost-user.c | 10 | ||||
| -rw-r--r-- | contrib/vhost-user-blk/vhost-user-blk.c | 4 |
2 files changed, 11 insertions, 3 deletions
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index b1e6072..d315db1 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -498,6 +498,16 @@ static bool vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg) { vmsg->payload.u64 = + /* + * The following VIRTIO feature bits are supported by our virtqueue + * implementation: + */ + 1ULL << VIRTIO_F_NOTIFY_ON_EMPTY | + 1ULL << VIRTIO_RING_F_INDIRECT_DESC | + 1ULL << VIRTIO_RING_F_EVENT_IDX | + 1ULL << VIRTIO_F_VERSION_1 | + + /* vhost-user feature bits */ 1ULL << VHOST_F_LOG_ALL | 1ULL << VHOST_USER_F_PROTOCOL_FEATURES; diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c index 6fd91c7..25eccd0 100644 --- a/contrib/vhost-user-blk/vhost-user-blk.c +++ b/contrib/vhost-user-blk/vhost-user-blk.c @@ -382,9 +382,7 @@ vub_get_features(VuDev *dev) 1ull << VIRTIO_BLK_F_DISCARD | 1ull << VIRTIO_BLK_F_WRITE_ZEROES | #endif - 1ull << VIRTIO_BLK_F_CONFIG_WCE | - 1ull << VIRTIO_F_VERSION_1 | - 1ull << VHOST_USER_F_PROTOCOL_FEATURES; + 1ull << VIRTIO_BLK_F_CONFIG_WCE; if (vdev_blk->enable_ro) { features |= 1ull << VIRTIO_BLK_F_RO; |