On 07/15/2015 03:57 PM, Paolo Bonzini wrote: > > On 15/07/2015 07:29, Jason Wang wrote: >> Cc: Stefan Hajnoczi <stefa...@redhat.com> >> Cc: Kevin Wolf <kw...@redhat.com> >> Cc: qemu-block@nongnu.org >> Signed-off-by: Jason Wang <jasow...@redhat.com> >> --- >> hw/block/virtio-blk.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c >> index 4c27974..761d763 100644 >> --- a/hw/block/virtio-blk.c >> +++ b/hw/block/virtio-blk.c >> @@ -731,7 +731,9 @@ static uint64_t virtio_blk_get_features(VirtIODevice >> *vdev, uint64_t features, >> virtio_add_feature(&features, VIRTIO_BLK_F_GEOMETRY); >> virtio_add_feature(&features, VIRTIO_BLK_F_TOPOLOGY); >> virtio_add_feature(&features, VIRTIO_BLK_F_BLK_SIZE); >> - virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); >> + if (s->conf.scsi) { >> + virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); >> + } > This must only be done for newer machine types only, or you change guest > ABI for scsi=off. Effectively you have to split it in two properties, > "scsi" and "always_set_f_scsi". > > Paolo
And always_set_f_scsi is true only for legacy machine types?