Il 19/08/2012 00:02, ronnie sahlberg ha scritto: > On Sun, Aug 19, 2012 at 7:58 AM, Paolo Bonzini <pbonz...@redhat.com> wrote: >> Il 17/08/2012 04:36, Ronnie Sahlberg ha scritto: >>> There is no bdrv_* API for the commands for burning a blank MMC disk >>> so when iSCSI LUNs are specified and the LUN is a MMC device with >>> 0 available blocks. This is a blank disk so force scsi generic. >>> >>> This allows the guest to talk directly to the target to burn data on >>> the disk. >>> >>> Signed-off-by: Ronnie Sahlberg <ronniesahlb...@gmail.com> >> >> What happens without the patch? It's ok that scsi-{hd,cd} does not >> work, but do scsi-{block,generic} work without the patch? >> > > Neither of them work, basically because in > block.c:find_image_format() > > if bs->sg is not set in > > if (bs->sg || !bdrv_is_inserted(bs)) { > > then we continue to > > ret = bdrv_pread(bs, 0, buf, sizeof(buf)); > > which fails with an error. > So this patch is basically to prevent find_image_format() from trying > to read from a blank disk. > > Maybe there is a better way to do this?
Ah, BTW does using -drive ...,format=raw work, or does it hiccup later again on something else? Paolo