Re: [Qemu-devel] [PATCH V4 2/3] virtio-blk: fail get_features when both scsi and 1.0 were set

[Paolo Bonzini <pbonzini@redhat.com>]

On 27/07/2015 11:49, Jason Wang wrote:
> +    if (__virtio_has_feature(features, VIRTIO_F_VERSION_1)) {

No double underscores in userspace code.  Longstanding so it can be
fixed after 2.4 is out---but please remember to do it.

> +        if (s->conf.scsi) {
> +            error_setg(errp, "Virtio 1.0 does not support scsi passthrough!");

Unclear error message, as one would expect SCSI passthrough not to work
anyway for e.g. a disk backed by a file.

It's not a big deal as long as you will disable VIRTIO_BLK_F_SCSI by
default in the same release that enables VIRTIO_F_VERSION_1 by default.

Paolo

> +            return 0;
> +        }
> +        virtio_add_feature(&features, VIRTIO_F_ANY_LAYOUT);
> +    } else {
> +        virtio_add_feature(&features, VIRTIO_BLK_F_SCSI);
> +    }