Re: [Qemu-devel] Summary of CD, DVD passthrough tests with -drive if=scsi

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Paolo Bonzini wrote:
> Yes, docs/qdev-device-use.txt helps.  "qemu -device virtio-blk,?" too.

I read it and ran '-device ?'. But both left me clueless.
The text i understood mainly as refering to "old ways" and "new way"
of defining devices. I stalled when i found no flesh for "HOST-OPTS"
and "DEV-OPTS". man ./qemu.1 lists options of -devices, but it did
not lead me to "virtio-blk" as driver name. 

Do i get it right that e.g.
  virtio-blk-pci.scsi=on/off
means there is an option
  -device virtio-blk,scsi=on

But how would i come from there to your proposal ?
  -device virtio-blk,drive=scsicd,logical_block_size=2048,physical_block_size=2048

Not nagging, just pointing out the problems of a noob.
To my luck, you are a very friendly tutor.
Else i would have failed early.


i wrote:
> > Can FreeBSD and Solaris use virtio drives ?

Paolo Bonzini wrote:
> Perhaps, but probably not with SG_IO so that's a "no" for your use case.

You mean SG_IO on the host system ?
On the guest, libburn would use CAM resp. uscsi.

I tried to learn about the overall concept of virtio but mostly
find prescriptions how to use it.
How much similarity between host and guest is needed ?


Actually i came to qemu because on the long term i want to see
GNU xorriso burn a DVD on GNU/Hurd. Just for fulfilling my duty
as GNU maintainer. (Not that anybody else would find this to
be a reasonable idea ... :))
But i understand that GNU/Hurd will not offer the guest support
for virtio. So i will have to resort to -cdrom for development
and an old PC for burn testing, if ever an RPC for userspace
SCSI transactions gets approved.
(Inside gnumach, there sit transaction calls for ATAPI and SCSI.
 But there is no way to use them directly from Hurd.)


Have a nice day :)

Thomas