From 3909c079454a49b113c60a5cd91d749f78ca1c7f Mon Sep 17 00:00:00 2001
From: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Date: Mon, 17 May 2021 16:06:28 +0300
Subject: [PATCH] virtio: disable ioeventfd for record/replay

virtio devices support separate iothreads waiting for
events from file descriptors. These are asynchronous
events that can't be recorded and replayed, therefore
this patch disables ioeventfd for all devices when
record or replay is enabled.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <162125678869.1252810.4317416444097392406.stgit@pasha-ThinkPad-X280>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/s390x/virtio-ccw.c   | 6 ++++++
 hw/virtio/virtio-mmio.c | 6 ++++++
 hw/virtio/virtio-pci.c  | 6 ++++++
 3 files changed, 18 insertions(+)

diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index d68888fccd06..6a2df1c1e9a9 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -31,6 +31,7 @@
 #include "trace.h"
 #include "hw/s390x/css-bridge.h"
 #include "hw/s390x/s390-virtio-ccw.h"
+#include "sysemu/replay.h"
 
 #define NR_CLASSIC_INDICATOR_BITS 64
 
@@ -770,6 +771,11 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, Error **errp)
         dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
     }
 
+    /* fd-based ioevents can't be synchronized in record/replay */
+    if (replay_mode != REPLAY_MODE_NONE) {
+        dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
+    }
+
     if (k->realize) {
         k->realize(dev, &err);
         if (err) {
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 5952471b38b8..1af48a1b0442 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -29,6 +29,7 @@
 #include "qemu/host-utils.h"
 #include "qemu/module.h"
 #include "sysemu/kvm.h"
+#include "sysemu/replay.h"
 #include "hw/virtio/virtio-mmio.h"
 #include "qemu/error-report.h"
 #include "qemu/log.h"
@@ -740,6 +741,11 @@ static void virtio_mmio_realizefn(DeviceState *d, Error **errp)
         proxy->flags &= ~VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD;
     }
 
+    /* fd-based ioevents can't be synchronized in record/replay */
+    if (replay_mode != REPLAY_MODE_NONE) {
+        proxy->flags &= ~VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD;
+    }
+
     if (proxy->legacy) {
         memory_region_init_io(&proxy->iomem, OBJECT(d),
                               &virtio_legacy_mem_ops, proxy,
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index b321604d9b37..f1e105fa52fd 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -37,6 +37,7 @@
 #include "qemu/range.h"
 #include "hw/virtio/virtio-bus.h"
 #include "qapi/visitor.h"
+#include "sysemu/replay.h"
 
 #define VIRTIO_PCI_REGION_SIZE(dev)     VIRTIO_PCI_CONFIG_OFF(msix_present(dev))
 
@@ -1760,6 +1761,11 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
         proxy->flags &= ~VIRTIO_PCI_FLAG_USE_IOEVENTFD;
     }
 
+    /* fd-based ioevents can't be synchronized in record/replay */
+    if (replay_mode != REPLAY_MODE_NONE) {
+        proxy->flags &= ~VIRTIO_PCI_FLAG_USE_IOEVENTFD;
+    }
+
     /*
      * virtio pci bar layout used by default.
      * subclasses can re-arrange things if needed.