libata-scsi: set CmdQue bit in standard INQUIRY data to 1
authorTom Yan <tom.ty89@gmail.com>
Tue, 12 Jul 2016 13:29:34 +0000 (21:29 +0800)
committerTejun Heo <tj@kernel.org>
Tue, 12 Jul 2016 14:54:54 +0000 (10:54 -0400)
Avoid performance bottleneck when being SCSI pass-through'd to
virtual machines with other OSes (e.g. Windows) via virtio-scsi
and scsi-block in qemu.

Ref.: https://github.com/YanVugenfirer/kvm-guest-drivers-windows/issues/63

Signed-off-by: Tom Yan <tom.ty89@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
drivers/ata/libata-scsi.c

index 3e79485..b0d4bba 100644 (file)
@@ -2097,7 +2097,10 @@ static unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf)
                0,
                0x5,    /* claim SPC-3 version compatibility */
                2,
-               95 - 4
+               95 - 4,
+               0,
+               0,
+               2
        };
 
        VPRINTK("ENTER\n");