[PATCH 2/2] virtio_pci: drop extra callback sync

[PATCH 2/2] virtio_pci: drop extra callback sync

[Michael S. Tsirkin]

virtio code synchronizes callbacks on reset now,
no need to do it in virtio pci.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/virtio/virtio_pci_legacy.c | 2 --
 drivers/virtio/virtio_pci_modern.c | 3 ---
 2 files changed, 5 deletions(-)

diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index d9cbb02b35a1..8115aa39e01e 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -98,8 +98,6 @@ static void vp_reset(struct virtio_device *vdev)
 	/* Flush out the status write, and flush in device writes,
 	 * including MSi-X interrupts, if any. */
 	vp_legacy_get_status(&vp_dev->ldev);
-	/* Flush pending VQ/configuration callbacks. */
-	vp_synchronize_vectors(vdev);
 }
 
 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 6d8ae2a6a8ca..c9e21317c51a 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -559,9 +559,6 @@ static void vp_reset(struct virtio_device *vdev)
 		msleep(1);
 
 	vp_modern_avq_cleanup(vdev);
-
-	/* Flush pending VQ/configuration callbacks. */
-	vp_synchronize_vectors(vdev);
 }
 
 static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
-- 
MST

[PATCH 1/2] virtio: synchronize callbacks after device reset

[Michael S. Tsirkin]

virtio_reset_device says:
	Note: this guarantees that vq callbacks are not in progress
but in practice, only virtio pci correctly synchronizes the cbs.

On other transports, a callback that is already executing, keeps running
while the driver tears down the state it uses.

Add virtio_synchronize_cbs to virtio_reset_device fixing this for all
transports that correctly implement synchronize_cbs().

Reported-by: Karl Mehltretter <kmehltretter@gmail.com>
Link: https://lore.kernel.org/all/20260818040433.66986-1-kmehltretter@gmail.com/
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 drivers/virtio/virtio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index b6c9e927bef5..a8588d7ad109 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -264,6 +264,8 @@ void virtio_reset_device(struct virtio_device *dev)
 #endif
 
 	dev->config->reset(dev);
+	/* Flush pending VQ/configuration callbacks. */
+	virtio_synchronize_cbs(dev);
 }
 EXPORT_SYMBOL_GPL(virtio_reset_device);
 
-- 
MST