Hi!
(I hope this will reach the SeaBIOS mailing list, because I'm not subscribed.)
I've reviewed this patch for RHEL-6 and now diffed the RHEL-6 patch with this one. I think the differences are all OK (source file list, handling of the VIRTIO_SCSI config option, bdf vs. pci, contents of struct virtio_scsi_config).
The only thing that *might* be an oversight is virtio_scsi_cmd() checking for VIRTIO_BLK_S_OK as response status (instead of VIRTIO_SCSI_S_OK as in RHEL-6), even thogh t SeaBIOS pach also #defines the latter macro. They both expand to 0, so it's only a source-documentation question.
Thanks, Laszlo