From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: Jason Wang <jasowang@redhat.com>, mst@redhat.com
Cc: eperezma@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org
Subject: Re: [PATCH 1/2] virtio: use virtio accessor to access packed descriptor flags
Date: Thu, 11 Nov 2021 08:51:22 +0100 [thread overview]
Message-ID: <cc07cc4c-38a3-9bf1-b16a-51c9ea4e0c5f@redhat.com> (raw)
In-Reply-To: <20211111063854.29060-1-jasowang@redhat.com>
On 11/11/21 07:38, Jason Wang wrote:
> We used to access packed descriptor flags via
> address_space_{write|read}_cached(). When we hit the cache, memcpy()
> is used which is not an atomic operation which may lead a wrong value
> is read or wrote.
>
> So this patch switches to use virito_{stw|lduw}_phys_cached() to make
> sure the aceess is atomic.
>
> Fixes: 86044b24e865f ("virtio: basic packed virtqueue support")
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> hw/virtio/virtio.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
next prev parent reply other threads:[~2021-11-11 7:52 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 6:38 [PATCH 1/2] virtio: use virtio accessor to access packed descriptor flags Jason Wang
2021-11-11 6:38 ` [PATCH 2/2] virtio: use virtio accessor to access packed event Jason Wang
2021-11-11 7:51 ` Philippe Mathieu-Daudé
2021-11-12 2:30 ` Jason Wang
2021-11-11 7:51 ` Philippe Mathieu-Daudé [this message]
2021-11-11 8:27 ` [PATCH 1/2] virtio: use virtio accessor to access packed descriptor flags Michael S. Tsirkin
2021-11-12 2:23 ` Jason Wang
2021-11-12 10:04 ` Michael S. Tsirkin
2021-11-15 4:20 ` Jason Wang
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