On 2026/09/08 23:36, Stefan Hajnoczi wrote:
On Tue, Sep 08, 2026 at 03:11:18PM +0900, Akihiko Odaki wrote:
Introduce virtio_complete_reset() as preparation to allow asynchronous
reset. It is unconditionally called in virtio_reset(), but a follow-up
change moves the call to each device implementation.
Signed-off-by: Akihiko Odaki <[email protected]>
---
include/hw/virtio/virtio.h | 1 +
hw/virtio/virtio.c | 14 +++++++++++---
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index c99cb19d8865..1431be1389f2 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -507,6 +507,7 @@ int virtio_queue_set_host_notifier_mr(VirtIODevice *vdev,
int n,
MemoryRegion *mr, bool assign);
int virtio_set_status(VirtIODevice *vdev, uint8_t val);
void virtio_reset(VirtIODevice *vdev);
+void virtio_complete_reset(VirtIODevice *vdev);
void virtio_queue_reset(VirtIODevice *vdev, uint32_t queue_index);
void virtio_queue_enable(VirtIODevice *vdev, uint32_t queue_index);
void virtio_update_irq(VirtIODevice *vdev);
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index daa5607338c9..8d5f58a02df6 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3423,11 +3423,10 @@ int virtio_set_features_ex(VirtIODevice *vdev, const
uint64_t *features)
void virtio_reset(VirtIODevice *vdev)
{
VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
- VirtioSharedMemory *shmem;
- uint64_t features[VIRTIO_FEATURES_NU64S];
- int i;
virtio_set_status(vdev, 0);
+ vdev->status = VIRTIO_CONFIG_S_FAILED;
Why is the VIRTIO Device Status Register set to FAILED during reset?
I don't see this in the VIRTIO specification.
The intent is to keep the status nonzero until virtio_complete_reset()
finishes the reset. Any bit would work, but I chose FAILED because it
looks saner than other options; the bit indicates that the guest is not
going to interact with the device until the reset completes, which is
indeed the case.
Regards,
Akihiko Odaki
+
if (current_cpu) {
/* Guest initiated reset */
vdev->device_endian = virtio_current_cpu_endian();
@@ -3448,6 +3447,15 @@ void virtio_reset(VirtIODevice *vdev)
k->reset(vdev);
}
+ virtio_complete_reset(vdev);
+}
+
+void virtio_complete_reset(VirtIODevice *vdev)
+{
+ VirtioSharedMemory *shmem;
+ uint64_t features[VIRTIO_FEATURES_NU64S];
+ int i;
+
vdev->start_on_kick = false;
vdev->started = false;
vdev->broken = false;
--
2.55.0
