Re: [PATCH v5 10/24] virtio-net: Use replay_schedule_bh_event for bhs that affect machine state

[Pavel Dovgalyuk]

Reviewed-by: Pavel Dovgalyuk <pavel.dovgal...@ispras.ru>

On 18.03.2024 18:46, Nicholas Piggin wrote:

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

Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
  hw/net/virtio-net.c | 11 ++++++-----
  1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 9959f1932b..6ac737f2cf 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"
@@ -416,7 +417,7 @@ 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) {
@@ -2724,7 +2725,7 @@ 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);
@@ -2879,7 +2880,7 @@ 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)

@@ -2962,7 +2963,7 @@ 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;
      }
@@ -2976,7 +2977,7 @@ 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;
      }
  }