Stefan Hajnoczi
2010-Dec-13 07:42 UTC
[Qemu-devel] SCSI Command support over VirtIO Block device
On Dec 13, 2010 5:14 AM, "????" <anuj01 at gmail.com> wrote:> > Hi > > I am trying to implement VirtIO support for a proprietary OS. And It > would be great if I am able to process SCSI commands over VirtIO Block > device. > > I tried to execute INQUIRY command but the status returned is UNSUPPORTED. > If anyone provide example VirtIO SCSI Command request structure for > INQUIRY command as per VirtIO spec Appendix D would be a great help. > > And also, the paragraph from VirtIO spec - 0.8.9 is confusing for me : > > "Historically, devices assumed that the fields type, ioprio and > sector reside in > a single, separate read-only buffer; the fields errors, data_len,sense_len and> residual reside in a single, separate write-only buffer; the sense > eld in a separate > write-only buffer of size 96 bytes, by itself; the fields errors, > data_len, sense_len > and residual in a single write-only buffer; and the status field is a > separate readonly > buffer of size 1 byte, by itself." > > Here 'status field of buffer size 1 byte' is whether readonly orwriteonly? Writeonly> > I want to know from which version of Qemu-kvm supports processing of > scsi commands over VirtIO block device as a backend. > Although I checked the Host Feature fields in which VIRTIO_BLK_F_SCSI > bit is set. I am using qemu-kvm version 0.12.3.Make sure you have a scsi-generic block device in qemu-kvm, not just a regular file or physical block device. Open /dev/sg. Look at hw/virtio-blk.c in qemu-kvm for host implementation details.> > -- > Anuj Aggarwal > > .''`. > : :? : # apt-get install hakuna-matata > `. `'` > `- >-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.linux-foundation.org/pipermail/virtualization/attachments/20101213/d54fca06/attachment.htm
Hi 2010/12/13 Stefan Hajnoczi <stefanha at gmail.com>:> > On Dec 13, 2010 5:14 AM, "????" <anuj01 at gmail.com> wrote: >> >> Hi >> >> I am trying to implement VirtIO support for a proprietary OS. And It >> would be great if I am able to process SCSI commands over VirtIO Block >> device. >> >> I tried to execute INQUIRY command but the status returned is UNSUPPORTED. >> If anyone provide example VirtIO SCSI Command request structure for >> INQUIRY command as per VirtIO spec Appendix D would be a great help. >> >> And also, the paragraph from VirtIO spec - 0.8.9 is confusing for me : >> >> "Historically, devices assumed that the ?fields type, ioprio and >> sector reside in >> a single, separate read-only buffer; the ?fields errors, data_len, >> sense_len and >> residual reside in a single, separate write-only buffer; the sense >> ?eld in a separate >> write-only buffer of size 96 bytes, by itself; the fields errors, >> data_len, sense_len >> and residual in a single write-only buffer; and the status field is a >> separate readonly >> buffer of size 1 byte, by itself." >> >> Here 'status field of buffer size 1 byte' is whether readonly or >> writeonly? > > Writeonly > >> >> I want to know from which version of Qemu-kvm supports processing of >> scsi commands over VirtIO block device as a backend. >> Although I checked the Host Feature fields in which VIRTIO_BLK_F_SCSI >> bit is set. I am using qemu-kvm version 0.12.3. > > Make sure you have a scsi-generic block device in qemu-kvm, not just a > regular file or physical block device. Open /dev/sg.Yes, I have given a file name instead of /dev/sg0. Now it's working as a charm. That means I can use physical disk as a VirtIO disk in guest OS. right? So it's kind of passthrough for a physical disk. But how can I distinguish among different physical disks attached to the host. is /dev/sg is different for each physical disk? However I thought VirtIO scsi device operations are for virtual disk (a regular file) also.> > Look at hw/virtio-blk.c in qemu-kvm for host implementation details. > >> >> -- > >> Anuj Aggarwal >> >> ?.''`. >> : :? :?? # apt-get install hakuna-matata >> `. `'` >> ?? `- >> >Thanks for your help. Regards -- Anuj Aggarwal ?.''`. : :? :?? # apt-get install hakuna-matata `. `'` ?? `-