[v6,08/10] virtio-net: Use replay_schedule_bh_event for bhs that affect machine state

Commit Message

Nicholas Piggin Aug. 13, 2024, 5:06 a.m. UTC

The regular qemu_bh_schedule() calls result in non-deterministic
execution of the bh in record-replay mode, which causes replay failure.

Reviewed-by: Alex Bennée <[e-mail]>
Reviewed-by: Pavel Dovgalyuk <[e-mail]>
Signed-off-by: Nicholas Piggin <[e-mail]>
---
 hw/net/virtio-net.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Patch

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 08aa0b65e3..10ebaae5e2 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -40,6 +40,7 @@ 
 #include "migration/misc.h"
 #include "standard-headers/linux/ethtool.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/replay.h"
 #include "trace.h"
 #include "monitor/qdev.h"
 #include "monitor/monitor.h"
@@ -417,7 +418,7 @@  static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
                 timer_mod(q->tx_timer,
                                qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
             } else {
-                qemu_bh_schedule(q->tx_bh);
+                replay_bh_schedule_event(q->tx_bh);
             }
         } else {
             if (q->tx_timer) {
@@ -2672,7 +2673,7 @@  static void virtio_net_tx_complete(NetClientState *nc, ssize_t len)
          */
         virtio_queue_set_notification(q->tx_vq, 0);
         if (q->tx_bh) {
-            qemu_bh_schedule(q->tx_bh);
+            replay_bh_schedule_event(q->tx_bh);
         } else {
             timer_mod(q->tx_timer,
                       qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);
@@ -2838,7 +2839,7 @@  static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
         return;
     }
     virtio_queue_set_notification(vq, 0);
-    qemu_bh_schedule(q->tx_bh);
+    replay_bh_schedule_event(q->tx_bh);
 }
 
 static void virtio_net_tx_timer(void *opaque)
@@ -2921,7 +2922,7 @@  static void virtio_net_tx_bh(void *opaque)
     /* If we flush a full burst of packets, assume there are
      * more coming and immediately reschedule */
     if (ret >= n->tx_burst) {
-        qemu_bh_schedule(q->tx_bh);
+        replay_bh_schedule_event(q->tx_bh);
         q->tx_waiting = 1;
         return;
     }
@@ -2935,7 +2936,7 @@  static void virtio_net_tx_bh(void *opaque)
         return;
     } else if (ret > 0) {
         virtio_queue_set_notification(q->tx_vq, 0);
-        qemu_bh_schedule(q->tx_bh);
+        replay_bh_schedule_event(q->tx_bh);
         q->tx_waiting = 1;
     }
 }