storvsc: force SPC-3 compliance on win8 and win8 r2 hosts
On win8 and win8 r2 hosts force SPC-3 compliance for MSFT virtual disks.
Ubuntu has been carrying a similar patch outside the tree for a while now.
Starting with win10, the host will support SPC-3 compliance. Based on all
the testing that has been done on win8 and win8 r2 hosts, we are comfortable
claiming SPC-3 compliance on these hosts as well. This will enable TRIM
support on these hosts.
Suggested by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index caa9f0e..efc6e44 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1394,6 +1394,19 @@
*/
sdevice->sdev_bflags |= msft_blist_flags;
+ /*
+ * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
+ * if the device is a MSFT virtual device.
+ */
+ if (!strncmp(sdevice->vendor, "Msft", 4)) {
+ switch (vmbus_proto_version) {
+ case VERSION_WIN8:
+ case VERSION_WIN8_1:
+ sdevice->scsi_level = SCSI_SPC_3;
+ break;
+ }
+ }
+
return 0;
}