1 files changed, 48 insertions, 9 deletions

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index d6f5b9ea3109..720104661d7f 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -953,8 +953,7 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 		     + pend_size;
 	int i;
 	u32 padding = 0;
-	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
-		packet->page_buf_cnt;
+	u32 page_count = packet->cp_partial ? 1 : packet->page_buf_cnt;
 	u32 remain;
 
 	/* Add padding */
@@ -1055,6 +1054,42 @@ static int netvsc_dma_map(struct hv_device *hv_dev,
 	return 0;
 }
 
+/* Build an "array" of mpb entries describing the data to be transferred
+ * over VMBus. After the desc header fields, each "array" entry is variable
+ * size, and each entry starts after the end of the previous entry. The
+ * "offset" and "len" fields for each entry imply the size of the entry.
+ *
+ * The pfns are in HV_HYP_PAGE_SIZE, because all communication with Hyper-V
+ * uses that granularity, even if the system page size of the guest is larger.
+ * Each entry in the input "pb" array must describe a contiguous range of
+ * guest physical memory so that the pfns are sequential if the range crosses
+ * a page boundary. The offset field must be < HV_HYP_PAGE_SIZE.
+ */
+static inline void netvsc_build_mpb_array(struct hv_page_buffer *pb,
+				u32 page_buffer_count,
+				struct vmbus_packet_mpb_array *desc,
+				u32 *desc_size)
+{
+	struct hv_mpb_array *mpb_entry = &desc->range;
+	int i, j;
+
+	for (i = 0; i < page_buffer_count; i++) {
+		u32 offset = pb[i].offset;
+		u32 len = pb[i].len;
+
+		mpb_entry->offset = offset;
+		mpb_entry->len = len;
+
+		for (j = 0; j < HVPFN_UP(offset + len); j++)
+			mpb_entry->pfn_array[j] = pb[i].pfn + j;
+
+		mpb_entry = (struct hv_mpb_array *)&mpb_entry->pfn_array[j];
+	}
+
+	desc->rangecount = page_buffer_count;
+	*desc_size = (char *)mpb_entry - (char *)desc;
+}
+
 static inline int netvsc_send_pkt(
 	struct hv_device *device,
 	struct hv_netvsc_packet *packet,
@@ -1097,8 +1132,11 @@ static inline int netvsc_send_pkt(
 
 	packet->dma_range = NULL;
 	if (packet->page_buf_cnt) {
+		struct vmbus_channel_packet_page_buffer desc;
+		u32 desc_size;
+
 		if (packet->cp_partial)
-			pb += packet->rmsg_pgcnt;
+			pb++;
 
 		ret = netvsc_dma_map(ndev_ctx->device_ctx, packet, pb);
 		if (ret) {
@@ -1106,11 +1144,12 @@ static inline int netvsc_send_pkt(
 			goto exit;
 		}
 
-		ret = vmbus_sendpacket_pagebuffer(out_channel,
-						  pb, packet->page_buf_cnt,
-						  &nvmsg, sizeof(nvmsg),
-						  req_id);
-
+		netvsc_build_mpb_array(pb, packet->page_buf_cnt,
+				(struct vmbus_packet_mpb_array *)&desc,
+				 &desc_size);
+		ret = vmbus_sendpacket_mpb_desc(out_channel,
+				(struct vmbus_packet_mpb_array *)&desc,
+				desc_size, &nvmsg, sizeof(nvmsg), req_id);
 		if (ret)
 			netvsc_dma_unmap(ndev_ctx->device_ctx, packet);
 	} else {
@@ -1259,7 +1298,7 @@ int netvsc_send(struct net_device *ndev,
 		packet->send_buf_index = section_index;
 
 		if (packet->cp_partial) {
-			packet->page_buf_cnt -= packet->rmsg_pgcnt;
+			packet->page_buf_cnt--;
 			packet->total_data_buflen = msd_len + packet->rmsg_size;
 		} else {
 			packet->page_buf_cnt = 0;