Hi, i sent the following to Paolo Bonzini and Stefan Hajnoczi.
Stefan advised > In the future I think it's appropriate to CC qemu-devel since others > in the community may be interested in virtio-scsi discussions too. So i forward my mail to this list. I am subscribed now. A first test report of SCSI passthrough without virtio-scsi will follow soon. -------------------------------------------------------------------- Hi, being unsure whether my cause is appropriate for qemu-devel list, i write directly to you, who recently discussed virtio-scsi on that list. If there is a better place, please direct me to it. I would like to participate as tester in the development of virtio-scsi. In the october 2011 archive of qemu-devel list, i found a link to http://wiki.qemu.org/Features/VirtioSCSI with Status: Under development. Not ready for real-world use yet. Features: [...] SCSI passthrough Is there an outlook when it will be ripe for testing SCSI transactions with CD-ish drives ? My goal is to operate a real DVD burner drive from within a Debian GNU/Linux 6.0.3 i386 as guest on a Debian GNU/Linux 6.0.2 amd64. The SCSI commands are transported by the guest system via ioctl(SG_IO). Burn program is xorriso, which uses libburn to communicate with the drive. I am developer of both, but quite a newbie when it comes to virtual machines. I have SCSI specs SPC, SBC, MMC, and some experience in reading and applying them. I can test with DVD drives at IDE/ATAPI, SATA, and USB on real installations of GNU/Linux, FreeBSD 8 and OpenSolaris svn 134. No experience with kernel programming or bus hardware issues. (libburn is an MMC driver in userspace.) --------------------------------------------------------------------- What i tried so far: The qemu version of Debian 6.0.2 is 0.12.5. So i also built 0.15.1 from the release tarball. I experienced no different behavior, though. I tried -drive file=/dev/sr1,if=virtio,media=cdrom which yields the same results as -drive if=scsi. (See below.) Especially the emulated drive identifies itself as vendor 'QEMU' product 'QEMU DVD-ROM' revision '0.15' rather than vendor 'TSSTcorp' product 'CDDVDW SH-S223B' revision 'SB02' of the real one. Obviously i do not get SCSI passthrough here. Before this i tried -cdrom /dev/sr1 The emulated QEMU DVD-ROM rev 0.12 and rev 0.15 expectedly turned out to be usable for reading only. With -drive file=/dev/sr1,if=scsi,bus=4,unit=0,media=cdrom the emulated QEMU DVD-ROM has similar restrictions as with -cdrom, and additionaly states that there is no medium loaded. E.g. with this SCSI transaction: TEST UNIT READY 00 00 00 00 00 00 +++ sense data = F0 00 02 00 00 00 00 0A 00 00 00 00 3A 00 00 00 00 00 +++ key=2 asc=3Ah ascq=00h ( 4 ms) The block device driver of GNU/Linux sees no medium either: dd: opening `/dev/sr0': No medium found This happens with real /dev/sr1 and with an ISO image in a regular file. --------------------------------------------------------------------- Have a nice day :) Thomas
