1 files changed, 151 insertions, 367 deletions

diff --git a/kernel/drivers/scsi/storvsc_drv.c b/kernel/drivers/scsi/storvsc_drv.c
index 3c6584ff6..3fba42ad9 100644
--- a/kernel/drivers/scsi/storvsc_drv.c
+++ b/kernel/drivers/scsi/storvsc_drv.c
@@ -56,15 +56,18 @@
  * V1 RC > 2008/1/31:  2.0
  * Win7: 4.2
  * Win8: 5.1
+ * Win8.1: 6.0
+ * Win10: 6.2
  */
 
+#define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)	((((MAJOR_) & 0xff) << 8) | \
+						(((MINOR_) & 0xff)))
 
-#define VMSTOR_WIN7_MAJOR 4
-#define VMSTOR_WIN7_MINOR 2
-
-#define VMSTOR_WIN8_MAJOR 5
-#define VMSTOR_WIN8_MINOR 1
-
+#define VMSTOR_PROTO_VERSION_WIN6	VMSTOR_PROTO_VERSION(2, 0)
+#define VMSTOR_PROTO_VERSION_WIN7	VMSTOR_PROTO_VERSION(4, 2)
+#define VMSTOR_PROTO_VERSION_WIN8	VMSTOR_PROTO_VERSION(5, 1)
+#define VMSTOR_PROTO_VERSION_WIN8_1	VMSTOR_PROTO_VERSION(6, 0)
+#define VMSTOR_PROTO_VERSION_WIN10	VMSTOR_PROTO_VERSION(6, 2)
 
 /*  Packet structure describing virtual storage requests. */
 enum vstor_packet_operation {
@@ -148,21 +151,18 @@ struct hv_fc_wwn_packet {
 
 /*
  * Sense buffer size changed in win8; have a run-time
- * variable to track the size we should use.
+ * variable to track the size we should use.  This value will
+ * likely change during protocol negotiation but it is valid
+ * to start by assuming pre-Win8.
  */
-static int sense_buffer_size;
+static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 
 /*
- * The size of the vmscsi_request has changed in win8. The
- * additional size is because of new elements added to the
- * structure. These elements are valid only when we are talking
- * to a win8 host.
- * Track the correction to size we need to apply.
- */
-
-static int vmscsi_size_delta;
-static int vmstor_current_major;
-static int vmstor_current_minor;
+ * The storage protocol version is determined during the
+ * initial exchange with the host.  It will indicate which
+ * storage functionality is available in the host.
+*/
+static int vmstor_proto_version;
 
 struct vmscsi_win8_extension {
 	/*
@@ -207,6 +207,56 @@ struct vmscsi_request {
 
 
 /*
+ * The size of the vmscsi_request has changed in win8. The
+ * additional size is because of new elements added to the
+ * structure. These elements are valid only when we are talking
+ * to a win8 host.
+ * Track the correction to size we need to apply. This value
+ * will likely change during protocol negotiation but it is
+ * valid to start by assuming pre-Win8.
+ */
+static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
+
+/*
+ * The list of storage protocols in order of preference.
+ */
+struct vmstor_protocol {
+	int protocol_version;
+	int sense_buffer_size;
+	int vmscsi_size_delta;
+};
+
+
+static const struct vmstor_protocol vmstor_protocols[] = {
+	{
+		VMSTOR_PROTO_VERSION_WIN10,
+		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
+		0
+	},
+	{
+		VMSTOR_PROTO_VERSION_WIN8_1,
+		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
+		0
+	},
+	{
+		VMSTOR_PROTO_VERSION_WIN8,
+		POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
+		0
+	},
+	{
+		VMSTOR_PROTO_VERSION_WIN7,
+		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
+		sizeof(struct vmscsi_win8_extension),
+	},
+	{
+		VMSTOR_PROTO_VERSION_WIN6,
+		PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
+		sizeof(struct vmscsi_win8_extension),
+	}
+};
+
+
+/*
  * This structure is sent during the intialization phase to get the different
  * properties of the channel.
  */
@@ -299,11 +349,14 @@ enum storvsc_request_type {
  */
 
 #define SRB_STATUS_AUTOSENSE_VALID	0x80
+#define SRB_STATUS_QUEUE_FROZEN		0x40
 #define SRB_STATUS_INVALID_LUN	0x20
 #define SRB_STATUS_SUCCESS	0x01
 #define SRB_STATUS_ABORTED	0x02
 #define SRB_STATUS_ERROR	0x04
 
+#define SRB_STATUS(status) \
+	(status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 /*
  * This is the end of Protocol specific defines.
  */
@@ -343,9 +396,6 @@ static void storvsc_on_channel_callback(void *context);
 struct storvsc_cmd_request {
 	struct scsi_cmnd *cmd;
 
-	unsigned int bounce_sgl_count;
-	struct scatterlist *bounce_sgl;
-
 	struct hv_device *device;
 
 	/* Synchronize the request/response if needed */
@@ -426,7 +476,6 @@ static void storvsc_host_scan(struct work_struct *work)
 	struct storvsc_scan_work *wrk;
 	struct Scsi_Host *host;
 	struct scsi_device *sdev;
-	unsigned long flags;
 
 	wrk = container_of(work, struct storvsc_scan_work, work);
 	host = wrk->host;
@@ -443,14 +492,8 @@ static void storvsc_host_scan(struct work_struct *work)
 	 * may have been removed this way.
 	 */
 	mutex_lock(&host->scan_mutex);
-	spin_lock_irqsave(host->host_lock, flags);
-	list_for_each_entry(sdev, &host->__devices, siblings) {
-		spin_unlock_irqrestore(host->host_lock, flags);
+	shost_for_each_device(sdev, host)
 		scsi_test_unit_ready(sdev, 1, 1, NULL);
-		spin_lock_irqsave(host->host_lock, flags);
-		continue;
-	}
-	spin_unlock_irqrestore(host->host_lock, flags);
 	mutex_unlock(&host->scan_mutex);
 	/*
 	 * Now scan the host to discover LUNs that may have been added.
@@ -481,18 +524,6 @@ done:
 	kfree(wrk);
 }
 
-/*
- * Major/minor macros.  Minor version is in LSB, meaning that earlier flat
- * version numbers will be interpreted as "0.x" (i.e., 1 becomes 0.1).
- */
-
-static inline u16 storvsc_get_version(u8 major, u8 minor)
-{
-	u16 version;
-
-	version = ((major << 8) | minor);
-	return version;
-}
 
 /*
  * We can get incoming messages from the host that are not in response to
@@ -555,241 +586,6 @@ get_in_err:
 
 }
 
-static void destroy_bounce_buffer(struct scatterlist *sgl,
-				  unsigned int sg_count)
-{
-	int i;
-	struct page *page_buf;
-
-	for (i = 0; i < sg_count; i++) {
-		page_buf = sg_page((&sgl[i]));
-		if (page_buf != NULL)
-			__free_page(page_buf);
-	}
-
-	kfree(sgl);
-}
-
-static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
-{
-	int i;
-
-	/* No need to check */
-	if (sg_count < 2)
-		return -1;
-
-	/* We have at least 2 sg entries */
-	for (i = 0; i < sg_count; i++) {
-		if (i == 0) {
-			/* make sure 1st one does not have hole */
-			if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
-				return i;
-		} else if (i == sg_count - 1) {
-			/* make sure last one does not have hole */
-			if (sgl[i].offset != 0)
-				return i;
-		} else {
-			/* make sure no hole in the middle */
-			if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
-				return i;
-		}
-	}
-	return -1;
-}
-
-static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
-						unsigned int sg_count,
-						unsigned int len,
-						int write)
-{
-	int i;
-	int num_pages;
-	struct scatterlist *bounce_sgl;
-	struct page *page_buf;
-	unsigned int buf_len = ((write == WRITE_TYPE) ? 0 : PAGE_SIZE);
-
-	num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
-
-	bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
-	if (!bounce_sgl)
-		return NULL;
-
-	sg_init_table(bounce_sgl, num_pages);
-	for (i = 0; i < num_pages; i++) {
-		page_buf = alloc_page(GFP_ATOMIC);
-		if (!page_buf)
-			goto cleanup;
-		sg_set_page(&bounce_sgl[i], page_buf, buf_len, 0);
-	}
-
-	return bounce_sgl;
-
-cleanup:
-	destroy_bounce_buffer(bounce_sgl, num_pages);
-	return NULL;
-}
-
-/* Assume the original sgl has enough room */
-static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
-					    struct scatterlist *bounce_sgl,
-					    unsigned int orig_sgl_count,
-					    unsigned int bounce_sgl_count)
-{
-	int i;
-	int j = 0;
-	unsigned long src, dest;
-	unsigned int srclen, destlen, copylen;
-	unsigned int total_copied = 0;
-	unsigned long bounce_addr = 0;
-	unsigned long dest_addr = 0;
-	unsigned long flags;
-	struct scatterlist *cur_dest_sgl;
-	struct scatterlist *cur_src_sgl;
-
-	local_irq_save(flags);
-	cur_dest_sgl = orig_sgl;
-	cur_src_sgl = bounce_sgl;
-	for (i = 0; i < orig_sgl_count; i++) {
-		dest_addr = (unsigned long)
-				kmap_atomic(sg_page(cur_dest_sgl)) +
-				cur_dest_sgl->offset;
-		dest = dest_addr;
-		destlen = cur_dest_sgl->length;
-
-		if (bounce_addr == 0)
-			bounce_addr = (unsigned long)kmap_atomic(
-							sg_page(cur_src_sgl));
-
-		while (destlen) {
-			src = bounce_addr + cur_src_sgl->offset;
-			srclen = cur_src_sgl->length - cur_src_sgl->offset;
-
-			copylen = min(srclen, destlen);
-			memcpy((void *)dest, (void *)src, copylen);
-
-			total_copied += copylen;
-			cur_src_sgl->offset += copylen;
-			destlen -= copylen;
-			dest += copylen;
-
-			if (cur_src_sgl->offset == cur_src_sgl->length) {
-				/* full */
-				kunmap_atomic((void *)bounce_addr);
-				j++;
-
-				/*
-				 * It is possible that the number of elements
-				 * in the bounce buffer may not be equal to
-				 * the number of elements in the original
-				 * scatter list. Handle this correctly.
-				 */
-
-				if (j == bounce_sgl_count) {
-					/*
-					 * We are done; cleanup and return.
-					 */
-					kunmap_atomic((void *)(dest_addr -
-						cur_dest_sgl->offset));
-					local_irq_restore(flags);
-					return total_copied;
-				}
-
-				/* if we need to use another bounce buffer */
-				if (destlen || i != orig_sgl_count - 1) {
-					cur_src_sgl = sg_next(cur_src_sgl);
-					bounce_addr = (unsigned long)
-							kmap_atomic(
-							sg_page(cur_src_sgl));
-				}
-			} else if (destlen == 0 && i == orig_sgl_count - 1) {
-				/* unmap the last bounce that is < PAGE_SIZE */
-				kunmap_atomic((void *)bounce_addr);
-			}
-		}
-
-		kunmap_atomic((void *)(dest_addr - cur_dest_sgl->offset));
-		cur_dest_sgl = sg_next(cur_dest_sgl);
-	}
-
-	local_irq_restore(flags);
-
-	return total_copied;
-}
-
-/* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
-static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
-					  struct scatterlist *bounce_sgl,
-					  unsigned int orig_sgl_count)
-{
-	int i;
-	int j = 0;
-	unsigned long src, dest;
-	unsigned int srclen, destlen, copylen;
-	unsigned int total_copied = 0;
-	unsigned long bounce_addr = 0;
-	unsigned long src_addr = 0;
-	unsigned long flags;
-	struct scatterlist *cur_src_sgl;
-	struct scatterlist *cur_dest_sgl;
-
-	local_irq_save(flags);
-
-	cur_src_sgl = orig_sgl;
-	cur_dest_sgl = bounce_sgl;
-
-	for (i = 0; i < orig_sgl_count; i++) {
-		src_addr = (unsigned long)
-				kmap_atomic(sg_page(cur_src_sgl)) +
-				cur_src_sgl->offset;
-		src = src_addr;
-		srclen = cur_src_sgl->length;
-
-		if (bounce_addr == 0)
-			bounce_addr = (unsigned long)
-					kmap_atomic(sg_page(cur_dest_sgl));
-
-		while (srclen) {
-			/* assume bounce offset always == 0 */
-			dest = bounce_addr + cur_dest_sgl->length;
-			destlen = PAGE_SIZE - cur_dest_sgl->length;
-
-			copylen = min(srclen, destlen);
-			memcpy((void *)dest, (void *)src, copylen);
-
-			total_copied += copylen;
-			cur_dest_sgl->length += copylen;
-			srclen -= copylen;
-			src += copylen;
-
-			if (cur_dest_sgl->length == PAGE_SIZE) {
-				/* full..move to next entry */
-				kunmap_atomic((void *)bounce_addr);
-				bounce_addr = 0;
-				j++;
-			}
-
-			/* if we need to use another bounce buffer */
-			if (srclen && bounce_addr == 0) {
-				cur_dest_sgl = sg_next(cur_dest_sgl);
-				bounce_addr = (unsigned long)
-						kmap_atomic(
-						sg_page(cur_dest_sgl));
-			}
-
-		}
-
-		kunmap_atomic((void *)(src_addr - cur_src_sgl->offset));
-		cur_src_sgl = sg_next(cur_src_sgl);
-	}
-
-	if (bounce_addr)
-		kunmap_atomic((void *)bounce_addr);
-
-	local_irq_restore(flags);
-
-	return total_copied;
-}
-
 static void handle_sc_creation(struct vmbus_channel *new_sc)
 {
 	struct hv_device *device = new_sc->primary_channel->device_obj;
@@ -885,7 +681,7 @@ static int storvsc_channel_init(struct hv_device *device)
 	struct storvsc_device *stor_device;
 	struct storvsc_cmd_request *request;
 	struct vstor_packet *vstor_packet;
-	int ret, t;
+	int ret, t, i;
 	int max_chns;
 	bool process_sub_channels = false;
 
@@ -921,41 +717,65 @@ static int storvsc_channel_init(struct hv_device *device)
 	}
 
 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
-	    vstor_packet->status != 0)
+	    vstor_packet->status != 0) {
+		ret = -EINVAL;
 		goto cleanup;
+	}
 
 
-	/* reuse the packet for version range supported */
-	memset(vstor_packet, 0, sizeof(struct vstor_packet));
-	vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
-	vstor_packet->flags = REQUEST_COMPLETION_FLAG;
+	for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
+		/* reuse the packet for version range supported */
+		memset(vstor_packet, 0, sizeof(struct vstor_packet));
+		vstor_packet->operation =
+			VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
+		vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 
-	vstor_packet->version.major_minor =
-		storvsc_get_version(vmstor_current_major, vmstor_current_minor);
+		vstor_packet->version.major_minor =
+			vmstor_protocols[i].protocol_version;
 
-	/*
-	 * The revision number is only used in Windows; set it to 0.
-	 */
-	vstor_packet->version.revision = 0;
+		/*
+		 * The revision number is only used in Windows; set it to 0.
+		 */
+		vstor_packet->version.revision = 0;
 
-	ret = vmbus_sendpacket(device->channel, vstor_packet,
+		ret = vmbus_sendpacket(device->channel, vstor_packet,
 			       (sizeof(struct vstor_packet) -
 				vmscsi_size_delta),
 			       (unsigned long)request,
 			       VM_PKT_DATA_INBAND,
 			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
-	if (ret != 0)
-		goto cleanup;
+		if (ret != 0)
+			goto cleanup;
 
-	t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
-	if (t == 0) {
-		ret = -ETIMEDOUT;
-		goto cleanup;
+		t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
+		if (t == 0) {
+			ret = -ETIMEDOUT;
+			goto cleanup;
+		}
+
+		if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO) {
+			ret = -EINVAL;
+			goto cleanup;
+		}
+
+		if (vstor_packet->status == 0) {
+			vmstor_proto_version =
+				vmstor_protocols[i].protocol_version;
+
+			sense_buffer_size =
+				vmstor_protocols[i].sense_buffer_size;
+
+			vmscsi_size_delta =
+				vmstor_protocols[i].vmscsi_size_delta;
+
+			break;
+		}
 	}
 
-	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
-	    vstor_packet->status != 0)
+	if (vstor_packet->status != 0) {
+		ret = -EINVAL;
 		goto cleanup;
+	}
 
 
 	memset(vstor_packet, 0, sizeof(struct vstor_packet));
@@ -979,8 +799,10 @@ static int storvsc_channel_init(struct hv_device *device)
 	}
 
 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
-	    vstor_packet->status != 0)
+	    vstor_packet->status != 0) {
+		ret = -EINVAL;
 		goto cleanup;
+	}
 
 	/*
 	 * Check to see if multi-channel support is there.
@@ -988,8 +810,7 @@ static int storvsc_channel_init(struct hv_device *device)
 	 * support multi-channel.
 	 */
 	max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
-	if ((vmbus_proto_version != VERSION_WIN7) &&
-	   (vmbus_proto_version != VERSION_WS2008))  {
+	if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 		if (vstor_packet->storage_channel_properties.flags &
 		    STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 			process_sub_channels = true;
@@ -1018,8 +839,10 @@ static int storvsc_channel_init(struct hv_device *device)
 	}
 
 	if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
-	    vstor_packet->status != 0)
+	    vstor_packet->status != 0) {
+		ret = -EINVAL;
 		goto cleanup;
+	}
 
 	if (process_sub_channels)
 		handle_multichannel_storage(device, max_chns);
@@ -1038,7 +861,7 @@ static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 	void (*process_err_fn)(struct work_struct *work);
 	bool do_work = false;
 
-	switch (vm_srb->srb_status) {
+	switch (SRB_STATUS(vm_srb->srb_status)) {
 	case SRB_STATUS_ERROR:
 		/*
 		 * If there is an error; offline the device since all
@@ -1113,15 +936,6 @@ static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 	host = stor_dev->host;
 
 	vm_srb = &cmd_request->vstor_packet.vm_srb;
-	if (cmd_request->bounce_sgl_count) {
-		if (vm_srb->data_in == READ_TYPE)
-			copy_from_bounce_buffer(scsi_sglist(scmnd),
-					cmd_request->bounce_sgl,
-					scsi_sg_count(scmnd),
-					cmd_request->bounce_sgl_count);
-		destroy_bounce_buffer(cmd_request->bounce_sgl,
-					cmd_request->bounce_sgl_count);
-	}
 
 	scmnd->result = vm_srb->scsi_status;
 
@@ -1416,6 +1230,9 @@ static int storvsc_device_configure(struct scsi_device *sdevice)
 
 	blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
 
+	/* Ensure there are no gaps in presented sgls */
+	blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
+
 	sdevice->no_write_same = 1;
 
 	/*
@@ -1428,15 +1245,19 @@ static int storvsc_device_configure(struct scsi_device *sdevice)
 
 	/*
 	 * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
-	 * if the device is a MSFT virtual device.
+	 * if the device is a MSFT virtual device.  If the host is
+	 * WIN10 or newer, allow write_same.
 	 */
 	if (!strncmp(sdevice->vendor, "Msft", 4)) {
-		switch (vmbus_proto_version) {
-		case VERSION_WIN8:
-		case VERSION_WIN8_1:
+		switch (vmstor_proto_version) {
+		case VMSTOR_PROTO_VERSION_WIN8:
+		case VMSTOR_PROTO_VERSION_WIN8_1:
 			sdevice->scsi_level = SCSI_SPC_3;
 			break;
 		}
+
+		if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
+			sdevice->no_write_same = 0;
 	}
 
 	return 0;
@@ -1563,7 +1384,7 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 	u32 payload_sz;
 	u32 length;
 
-	if (vmstor_current_major <= VMSTOR_WIN8_MAJOR) {
+	if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
 		/*
 		 * On legacy hosts filter unimplemented commands.
 		 * Future hosts are expected to correctly handle
@@ -1585,8 +1406,7 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 	vm_srb->win8_extension.time_out_value = 60;
 
 	vm_srb->win8_extension.srb_flags |=
-		(SRB_FLAGS_QUEUE_ACTION_ENABLE |
-		SRB_FLAGS_DISABLE_SYNCH_TRANSFER);
+		SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
 
 	/* Build the SRB */
 	switch (scmnd->sc_data_direction) {
@@ -1598,10 +1418,18 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 		vm_srb->data_in = READ_TYPE;
 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
 		break;
-	default:
+	case DMA_NONE:
 		vm_srb->data_in = UNKNOWN_TYPE;
 		vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
 		break;
+	default:
+		/*
+		 * This is DMA_BIDIRECTIONAL or something else we are never
+		 * supposed to see here.
+		 */
+		WARN(1, "Unexpected data direction: %d\n",
+		     scmnd->sc_data_direction);
+		return -EINVAL;
 	}
 
 
@@ -1622,40 +1450,13 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 	payload_sz = sizeof(cmd_request->mpb);
 
 	if (sg_count) {
-		/* check if we need to bounce the sgl */
-		if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
-			cmd_request->bounce_sgl =
-				create_bounce_buffer(sgl, sg_count,
-						     length,
-						     vm_srb->data_in);
-			if (!cmd_request->bounce_sgl)
-				return SCSI_MLQUEUE_HOST_BUSY;
-
-			cmd_request->bounce_sgl_count =
-				ALIGN(length, PAGE_SIZE) >> PAGE_SHIFT;
-
-			if (vm_srb->data_in == WRITE_TYPE)
-				copy_to_bounce_buffer(sgl,
-					cmd_request->bounce_sgl, sg_count);
-
-			sgl = cmd_request->bounce_sgl;
-			sg_count = cmd_request->bounce_sgl_count;
-		}
-
-
 		if (sg_count > MAX_PAGE_BUFFER_COUNT) {
 
 			payload_sz = (sg_count * sizeof(void *) +
 				      sizeof(struct vmbus_packet_mpb_array));
 			payload = kmalloc(payload_sz, GFP_ATOMIC);
-			if (!payload) {
-				if (cmd_request->bounce_sgl_count)
-					destroy_bounce_buffer(
-					cmd_request->bounce_sgl,
-					cmd_request->bounce_sgl_count);
-
-					return SCSI_MLQUEUE_DEVICE_BUSY;
-			}
+			if (!payload)
+				return SCSI_MLQUEUE_DEVICE_BUSY;
 		}
 
 		payload->range.len = length;
@@ -1684,11 +1485,6 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 
 	if (ret == -EAGAIN) {
 		/* no more space */
-
-		if (cmd_request->bounce_sgl_count)
-			destroy_bounce_buffer(cmd_request->bounce_sgl,
-					cmd_request->bounce_sgl_count);
-
 		return SCSI_MLQUEUE_DEVICE_BUSY;
 	}
 
@@ -1758,22 +1554,11 @@ static int storvsc_probe(struct hv_device *device,
 	 * set state to properly communicate with the host.
 	 */
 
-	switch (vmbus_proto_version) {
-	case VERSION_WS2008:
-	case VERSION_WIN7:
-		sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
-		vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
-		vmstor_current_major = VMSTOR_WIN7_MAJOR;
-		vmstor_current_minor = VMSTOR_WIN7_MINOR;
+	if (vmbus_proto_version < VERSION_WIN8) {
 		max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
 		max_targets = STORVSC_IDE_MAX_TARGETS;
 		max_channels = STORVSC_IDE_MAX_CHANNELS;
-		break;
-	default:
-		sense_buffer_size = POST_WIN7_STORVSC_SENSE_BUFFER_SIZE;
-		vmscsi_size_delta = 0;
-		vmstor_current_major = VMSTOR_WIN8_MAJOR;
-		vmstor_current_minor = VMSTOR_WIN8_MINOR;
+	} else {
 		max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
 		max_targets = STORVSC_MAX_TARGETS;
 		max_channels = STORVSC_MAX_CHANNELS;
@@ -1783,7 +1568,6 @@ static int storvsc_probe(struct hv_device *device,
 		 * VCPUs in the guest.
 		 */
 		max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
-		break;
 	}
 
 	scsi_driver.can_queue = (max_outstanding_req_per_channel *