[PATCH net] vhost: flush dcache page when logging dirty pages

[Jason Wang]

We set dirty bit through setting up kmaps and access them through
kernel virtual address, this may result alias in virtually tagged
caches that require a dcache flush afterwards.

Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server")
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
 drivers/vhost/vhost.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 351af88231ad..34a1cedbc5ba 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1711,6 +1711,7 @@ static int set_bit_to_user(int nr, void __user *addr)
 	base = kmap_atomic(page);
 	set_bit(bit, base);
 	kunmap_atomic(base);
+	flush_dcache_page(page);
 	set_page_dirty_lock(page);
 	put_page(page);
 	return 0;
-- 
2.19.1