scsi: storvsc: Retrieve information about the capability of the target

The storage protocol informs the guest of the I/O capabilities of the storage
stack. Retrieve this information and use it in the guest.

Signed-off-by: K. Y. Srinivasan <[email protected]>
Reviewed-by: Long Li <[email protected]>
Signed-off-by: James Bottomley <[email protected]>

drivers/scsi/storvsc_drv.c

@@ -377,6 +377,10 @@ struct storvsc_device {
 	unsigned char path_id;
 	unsigned char target_id;
 
+	/*
+	 * Max I/O, the device can support.
+	 */
+	u32   max_transfer_bytes;
 	/* Used for vsc/vsp channel reset process */
 	struct storvsc_cmd_request init_request;
 	struct storvsc_cmd_request reset_request;
@@ -974,6 +978,8 @@ static int storvsc_channel_init(struct hv_device *device)
 		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 			process_sub_channels = true;
 	}
+	stor_device->max_transfer_bytes =
+		vstor_packet->storage_channel_properties.max_transfer_bytes;
 
 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
 	vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;