stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Michael Kelley <mikelley@microsoft.com>
To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
	decui@microsoft.com, davem@davemloft.net, edumazet@google.com,
	kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org,
	linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: mikelley@microsoft.com, stable@vger.kernel.org
Subject: [PATCH net 1/1] hv_netvsc: Fix missed pagebuf entries in netvsc_dma_map/unmap()
Date: Mon, 30 Jan 2023 19:33:06 -0800	[thread overview]
Message-ID: <1675135986-254490-1-git-send-email-mikelley@microsoft.com> (raw)

netvsc_dma_map() and netvsc_dma_unmap() currently check the cp_partial
flag and adjust the page_count so that pagebuf entries for the RNDIS
portion of the message are skipped when it has already been copied into
a send buffer. But this adjustment has already been made by code in
netvsc_send(). The duplicate adjustment causes some pagebuf entries to
not be mapped. In a normal VM, this doesn't break anything because the
mapping doesn’t change the PFN. But in a Confidential VM,
dma_map_single() does bounce buffering and provides a different PFN.
Failing to do the mapping causes the wrong PFN to be passed to Hyper-V,
and various errors ensue.

Fix this by removing the duplicate adjustment in netvsc_dma_map() and
netvsc_dma_unmap().

Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver")
Cc: stable@vger.kernel.org
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
 drivers/net/hyperv/netvsc.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 661bbe6..8acfa40 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -949,9 +949,6 @@ static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 void netvsc_dma_unmap(struct hv_device *hv_dev,
 		      struct hv_netvsc_packet *packet)
 {
-	u32 page_count = packet->cp_partial ?
-		packet->page_buf_cnt - packet->rmsg_pgcnt :
-		packet->page_buf_cnt;
 	int i;
 
 	if (!hv_is_isolation_supported())
@@ -960,7 +957,7 @@ void netvsc_dma_unmap(struct hv_device *hv_dev,
 	if (!packet->dma_range)
 		return;
 
-	for (i = 0; i < page_count; i++)
+	for (i = 0; i < packet->page_buf_cnt; i++)
 		dma_unmap_single(&hv_dev->device, packet->dma_range[i].dma,
 				 packet->dma_range[i].mapping_size,
 				 DMA_TO_DEVICE);
@@ -990,9 +987,7 @@ static int netvsc_dma_map(struct hv_device *hv_dev,
 			  struct hv_netvsc_packet *packet,
 			  struct hv_page_buffer *pb)
 {
-	u32 page_count =  packet->cp_partial ?
-		packet->page_buf_cnt - packet->rmsg_pgcnt :
-		packet->page_buf_cnt;
+	u32 page_count = packet->page_buf_cnt;
 	dma_addr_t dma;
 	int i;
 
-- 
1.8.3.1


             reply	other threads:[~2023-01-31  3:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-31  3:33 Michael Kelley [this message]
2023-01-31 17:01 ` [PATCH net 1/1] hv_netvsc: Fix missed pagebuf entries in netvsc_dma_map/unmap() Haiyang Zhang
2023-02-02  5:01 ` Jakub Kicinski
2023-02-02  5:20   ` Michael Kelley (LINUX)
2023-02-02  8:30     ` Paolo Abeni
2023-02-02 19:24       ` Michael Kelley (LINUX)
2023-02-02  8:40 ` patchwork-bot+netdevbpf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1675135986-254490-1-git-send-email-mikelley@microsoft.com \
    --to=mikelley@microsoft.com \
    --cc=davem@davemloft.net \
    --cc=decui@microsoft.com \
    --cc=edumazet@google.com \
    --cc=haiyangz@microsoft.com \
    --cc=kuba@kernel.org \
    --cc=kys@microsoft.com \
    --cc=linux-hyperv@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    --cc=stable@vger.kernel.org \
    --cc=wei.liu@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).