hv_netvsc: Use HV_HYP_PAGE_SIZE for Hyper-V communication

When communicating with Hyper-V, HV_HYP_PAGE_SIZE should be used since
that's the page size used by Hyper-V and Hyper-V expects all
page-related data using the unit of HY_HYP_PAGE_SIZE, for example, the
"pfn" in hv_page_buffer is actually the HV_HYP_PAGE (i.e. the Hyper-V
page) number.

In order to support guest whose page size is not 4k, we need to make
hv_netvsc always use HV_HYP_PAGE_SIZE for Hyper-V communication.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-8-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>

drivers/net/hyperv/netvsc.c

@@ -794,7 +794,7 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 	}
 
 	for (i = 0; i < page_count; i++) {
-		char *src = phys_to_virt(pb[i].pfn << PAGE_SHIFT);
+		char *src = phys_to_virt(pb[i].pfn << HV_HYP_PAGE_SHIFT);
 		u32 offset = pb[i].offset;
 		u32 len = pb[i].len;
 

drivers/net/hyperv/netvsc_drv.c

@@ -373,32 +373,29 @@ static u16 netvsc_select_queue(struct net_device *ndev, struct sk_buff *skb,
 	return txq;
 }
 
-static u32 fill_pg_buf(struct page *page, u32 offset, u32 len,
+static u32 fill_pg_buf(unsigned long hvpfn, u32 offset, u32 len,
 		       struct hv_page_buffer *pb)
 {
 	int j = 0;
 
-	/* Deal with compound pages by ignoring unused part
-	 * of the page.
-	 */
-	page += (offset >> PAGE_SHIFT);
-	offset &= ~PAGE_MASK;
+	hvpfn += offset >> HV_HYP_PAGE_SHIFT;
+	offset = offset & ~HV_HYP_PAGE_MASK;
 
 	while (len > 0) {
 		unsigned long bytes;
 
-		bytes = PAGE_SIZE - offset;
+		bytes = HV_HYP_PAGE_SIZE - offset;
 		if (bytes > len)
 			bytes = len;
-		pb[j].pfn = page_to_pfn(page);
+		pb[j].pfn = hvpfn;
 		pb[j].offset = offset;
 		pb[j].len = bytes;
 
 		offset += bytes;
 		len -= bytes;
 
-		if (offset == PAGE_SIZE && len) {
-			page++;
+		if (offset == HV_HYP_PAGE_SIZE && len) {
+			hvpfn++;
 			offset = 0;
 			j++;
 		}
@@ -421,23 +418,26 @@ static u32 init_page_array(void *hdr, u32 len, struct sk_buff *skb,
 	 * 2. skb linear data
 	 * 3. skb fragment data
 	 */
-	slots_used += fill_pg_buf(virt_to_page(hdr),
-				  offset_in_page(hdr),
-				  len, &pb[slots_used]);
+	slots_used += fill_pg_buf(virt_to_hvpfn(hdr),
+				  offset_in_hvpage(hdr),
+				  len,
+				  &pb[slots_used]);
 
 	packet->rmsg_size = len;
 	packet->rmsg_pgcnt = slots_used;
 
-	slots_used += fill_pg_buf(virt_to_page(data),
-				offset_in_page(data),
-				skb_headlen(skb), &pb[slots_used]);
+	slots_used += fill_pg_buf(virt_to_hvpfn(data),
+				  offset_in_hvpage(data),
+				  skb_headlen(skb),
+				  &pb[slots_used]);
 
 	for (i = 0; i < frags; i++) {
 		skb_frag_t *frag = skb_shinfo(skb)->frags + i;
 
-		slots_used += fill_pg_buf(skb_frag_page(frag),
-					skb_frag_off(frag),
-					skb_frag_size(frag), &pb[slots_used]);
+		slots_used += fill_pg_buf(page_to_hvpfn(skb_frag_page(frag)),
+					  skb_frag_off(frag),
+					  skb_frag_size(frag),
+					  &pb[slots_used]);
 	}
 	return slots_used;
 }
@@ -453,21 +453,21 @@ static int count_skb_frag_slots(struct sk_buff *skb)
 		unsigned long offset = skb_frag_off(frag);
 
 		/* Skip unused frames from start of page */
-		offset &= ~PAGE_MASK;
-		pages += PFN_UP(offset + size);
+		offset &= ~HV_HYP_PAGE_MASK;
+		pages += HVPFN_UP(offset + size);
 	}
 	return pages;
 }
 
 static int netvsc_get_slots(struct sk_buff *skb)
 {
 	char *data = skb->data;
-	unsigned int offset = offset_in_page(data);
+	unsigned int offset = offset_in_hvpage(data);
 	unsigned int len = skb_headlen(skb);
 	int slots;
 	int frag_slots;
 
-	slots = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+	slots = DIV_ROUND_UP(offset + len, HV_HYP_PAGE_SIZE);
 	frag_slots = count_skb_frag_slots(skb);
 	return slots + frag_slots;
 }

drivers/net/hyperv/rndis_filter.c

@@ -25,7 +25,7 @@
 
 static void rndis_set_multicast(struct work_struct *w);
 
-#define RNDIS_EXT_LEN PAGE_SIZE
+#define RNDIS_EXT_LEN HV_HYP_PAGE_SIZE
 struct rndis_request {
 	struct list_head list_ent;
 	struct completion  wait_event;
@@ -215,18 +215,17 @@ static int rndis_filter_send_request(struct rndis_device *dev,
 	packet->page_buf_cnt = 1;
 
 	pb[0].pfn = virt_to_phys(&req->request_msg) >>
-					PAGE_SHIFT;
+					HV_HYP_PAGE_SHIFT;
 	pb[0].len = req->request_msg.msg_len;
-	pb[0].offset =
-		(unsigned long)&req->request_msg & (PAGE_SIZE - 1);
+	pb[0].offset = offset_in_hvpage(&req->request_msg);
 
 	/* Add one page_buf when request_msg crossing page boundary */
-	if (pb[0].offset + pb[0].len > PAGE_SIZE) {
+	if (pb[0].offset + pb[0].len > HV_HYP_PAGE_SIZE) {
 		packet->page_buf_cnt++;
-		pb[0].len = PAGE_SIZE -
+		pb[0].len = HV_HYP_PAGE_SIZE -
 			pb[0].offset;
 		pb[1].pfn = virt_to_phys((void *)&req->request_msg
-			+ pb[0].len) >> PAGE_SHIFT;
+			+ pb[0].len) >> HV_HYP_PAGE_SHIFT;
 		pb[1].offset = 0;
 		pb[1].len = req->request_msg.msg_len -
 			pb[0].len;