On Wed, 22 Jul 2015 13:59:51 +0800 Jason Wang <jasow...@redhat.com> wrote:
> SCSI passthrough was no longer supported in virtio 1.0, so this patch > fail the get_features() when both 1.0 and scsi is set. And also only > advertise VIRTIO_BLK_F_SCSI for legacy virtio-blk device. > > Signed-off-by: Jason Wang <jasow...@redhat.com> > --- > hw/block/virtio-blk.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c > index 4c27974..4716c3e 100644 > --- a/hw/block/virtio-blk.c > +++ b/hw/block/virtio-blk.c > @@ -731,7 +731,14 @@ 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 (__virtio_has_feature(features, VIRTIO_F_VERSION_1)) { > + if (s->conf.scsi) { > + error_setg(errp, "Virtio 1.0 does not support scsi > passthrough!"); > + return 0; > + } > + } else { > + virtio_add_feature(&features, VIRTIO_BLK_F_SCSI); > + } > > if (s->conf.config_wce) { > virtio_add_feature(&features, VIRTIO_BLK_F_CONFIG_WCE); Do we advertise F_SCSI even if scsi is not configured in order to keep the same bits as before? I'm afraid I don't remember, that thread was long :/ I'm asking because I'd like to depend on that bit to decide whether I can negotiate revision 1 for ccw and subsequently offer VERSION_1. It would be an easy thing to do, and I'd like to avoid mucking around with device-specific configuration from the transport. To illustrate what I'm talking about, my current patchset for virtio-1 on ccw is here: git://github.com/cohuck/qemu virtio-1-ccw-2.5