From 983924532f61091fd90d1f2fafa4aa938c414dbb Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Fri, 25 May 2012 21:59:01 +1000 Subject: ISCSI: Add SCSI passthrough via scsi-generic to libiscsi Update iscsi to allow passthrough of SG_IO scsi commands when the iscsi device is forced to be scsi-generic. Implement both bdrv_ioctl() and bdrv_aio_ioctl() in the iscsi backend, emulate the SG_IO ioctl and pass the SCSI commands across to the iscsi target. This allows end-to-end passthrough of SCSI all the way from the guest, to qemu, via scsi-generic, then libiscsi all the way to the iscsi target. To activate this you need to specify that the iscsi lun should be treated as a scsi-generic device. Example: -device lsi -device scsi-generic,drive=MyISCSI \ -drive file=iscsi://10.1.1.125/iqn.ronnie.test/1,if=none,id=MyISCSI Note, you can currently not boot a qemu guest from a scsi device. Note, This only works when the host is linux, since the emulation relies on definitions of SG_IO from the scsi-generic implementation in the linux kernel. It should be fairly easy to re-implement some structures similar enough for non-linux hosts to do the same style of passthrough via a fake scsi generic layer and libiscsi if need be. Signed-off-by: Ronnie Sahlberg Signed-off-by: Paolo Bonzini --- hw/scsi-generic.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'hw') diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c index d856d23b3b..8d5106061e 100644 --- a/hw/scsi-generic.c +++ b/hw/scsi-generic.c @@ -400,12 +400,6 @@ static int scsi_generic_initfn(SCSIDevice *s) return -1; } - /* check we are really using a /dev/sg* file */ - if (!bdrv_is_sg(s->conf.bs)) { - error_report("not /dev/sg*"); - return -1; - } - if (bdrv_get_on_error(s->conf.bs, 0) != BLOCK_ERR_STOP_ENOSPC) { error_report("Device doesn't support drive option werror"); return -1; @@ -416,8 +410,11 @@ static int scsi_generic_initfn(SCSIDevice *s) } /* check we are using a driver managing SG_IO (version 3 and after */ - if (bdrv_ioctl(s->conf.bs, SG_GET_VERSION_NUM, &sg_version) < 0 || - sg_version < 30000) { + if (bdrv_ioctl(s->conf.bs, SG_GET_VERSION_NUM, &sg_version) < 0) { + error_report("scsi generic interface not supported"); + return -1; + } + if (sg_version < 30000) { error_report("scsi generic interface too old"); return -1; } -- cgit v1.2.3