This patch forces SPC-3 for Hyper-V disks on the VMBus. As Windows 10's
virtual SAS bus is SPC-3 compliant and there are no negative side effects
on forcing SPC-3 compliance for Win8 hosts, this patch enables SPC-3
compliance by forcing it on for hosts with versions later than Win8.
Forcing SPC-3 compliance for hosts earlier than Win10 also enables
TRIM support.
Suggested by: James Bottomley <[email protected]>
Signed-off-by: Jeff Leung <[email protected]>
---
drivers/scsi/storvsc_drv.c | 9 +++++++++
1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index ed0f899..afcc68e 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1449,6 +1449,15 @@ static int storvsc_device_configure(struct scsi_device *sdevice)
sdevice->no_write_same = 1;
+ /*
+ * If the host is Win2k12 or later, we pretend to be SPC-3 compliant
+ * and send RC16 which activates TRIM. We will only enable this on a
+ * host with levels greater than VERSION_WIN8
+ */
+ if (vmbus_proto_version >= VERSION_WIN8) {
+ sdevice->scsi_level = SCSI_SPC_3;
+ }
+
return 0;
}
--
1.7.2.5
> -----Original Message-----
> From: Jeff Leung [mailto:[email protected]]
> Sent: Monday, October 20, 2014 10:39 PM
> To: [email protected]; [email protected];
> [email protected]
> Cc: KY Srinivasan; [email protected]; Jeff Leung
> Subject: [PATCH] scsi: storvsc: Force SPC-3 for Win8 Hosts or Later
>
> This patch forces SPC-3 for Hyper-V disks on the VMBus. As Windows 10's
> virtual SAS bus is SPC-3 compliant and there are no negative side effects on
> forcing SPC-3 compliance for Win8 hosts, this patch enables SPC-3 compliance
> by forcing it on for hosts with versions later than Win8.
>
> Forcing SPC-3 compliance for hosts earlier than Win10 also enables TRIM
> support.
>
> Suggested by: James Bottomley
> <[email protected]>
> Signed-off-by: Jeff Leung <[email protected]>
> ---
> drivers/scsi/storvsc_drv.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index
> ed0f899..afcc68e 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1449,6 +1449,15 @@ static int storvsc_device_configure(struct
> scsi_device *sdevice)
>
> sdevice->no_write_same = 1;
>
> + /*
> + * If the host is Win2k12 or later, we pretend to be SPC-3 compliant
> + * and send RC16 which activates TRIM. We will only enable this on a
> + * host with levels greater than VERSION_WIN8
> + */
> + if (vmbus_proto_version >= VERSION_WIN8) {
I would want this hack not to be in Windows 10. We can have this hack if the host is either
Ws2012 or ws2012 r2 (VERSION_WIN8 or VERSION_WIN8_1). Also this hack should apply only
to VHD's being presented and not pass through devices.
K. Y
> + sdevice->scsi_level = SCSI_SPC_3;
> + }
> +
> return 0;
> }
>
> --
> 1.7.2.5