[Stable-8.2.6,20/23] virtio: remove virtio_tswap16s() call in vring_packed_event_read()

Commit Message

Michael Tokarev July 15, 2024, 7:46 a.m. UTC

From: Stefano Garzarella <[e-mail]>

Commit d152cdd6f6 ("virtio: use virtio accessor to access packed event")
switched using of address_space_read_cached() to virito_lduw_phys_cached()
to access packed descriptor event.

When we used address_space_read_cached(), we needed to call
virtio_tswap16s() to handle the endianess of the field, but
virito_lduw_phys_cached() already handles it internally, so we no longer
need to call virtio_tswap16s() (as the commit had done for `off_wrap`,
but forgot for `flags`).

Fixes: d152cdd6f6 ("virtio: use virtio accessor to access packed event")
Cc: [e-mail]
Cc: [e-mail]
Reported-by: Xoykie <[e-mail]>
Link: https://lore.kernel.org/qemu-devel/[e-mail]
Signed-off-by: Stefano Garzarella <[e-mail]>
Message-Id: <[e-mail]>
Acked-by: Jason Wang <[e-mail]>
Reviewed-by: Peter Maydell <[e-mail]>
Reviewed-by: Eugenio Pérez <[e-mail]>
Reviewed-by: Michael S. Tsirkin <[e-mail]>
Signed-off-by: Michael S. Tsirkin <[e-mail]>
(cherry picked from commit 7aa6492401e95fb296dec7cda81e67d91f6037d7)
Signed-off-by: Michael Tokarev <[e-mail]>

Patch

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index c177c31ca0..157567912e 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -322,7 +322,6 @@  static void vring_packed_event_read(VirtIODevice *vdev,
     /* Make sure flags is seen before off_wrap */
     smp_rmb();
     e->off_wrap = virtio_lduw_phys_cached(vdev, cache, off_off);
-    virtio_tswap16s(vdev, &e->flags);
 }
 
 static void vring_packed_off_wrap_write(VirtIODevice *vdev,