[Qemu-devel] [PATCH 4/4] virtio-mmio: add a new property for ioeventfd

[Ying-Shiuan Pan <yingshiuan.pan@gmail.com>]

Make ioeventfd could be enabled or disabled (default). Since ioeventfd
is not yet ready in kvm-arm, without this option, qemu will get a
problem if it attempts to initialize ioeventfd.

To coincide this option of virtio-mmio with virtio-pci, I would like to
also move VIRTIO_PCI_FLAG_USE_IOEVENTFD to 'bool ioeventfd' of VirtIODevice.
Any better suggestion?

Signed-off-by: Ying-Shiuan Pan <yspan@itri.org.tw>
---
 hw/block/virtio-blk.c      | 1 +
 hw/net/virtio-net.c        | 1 +
 hw/virtio/virtio-mmio.c    | 3 ++-
 include/hw/virtio/virtio.h | 1 +
 4 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 19d0961..befdfdf 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -756,6 +756,7 @@ static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
 
 static Property virtio_blk_properties[] = {
     DEFINE_VIRTIO_BLK_PROPERTIES(VirtIOBlock, blk),
+    DEFINE_PROP_BOOL("ioeventfd", VirtIOBlock, parent_obj.use_ioeventfd, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3626608..9b75e61 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1631,6 +1631,7 @@ static Property virtio_net_properties[] = {
                                                TX_TIMER_INTERVAL),
     DEFINE_PROP_INT32("x-txburst", VirtIONet, net_conf.txburst, TX_BURST),
     DEFINE_PROP_STRING("tx", VirtIONet, net_conf.tx),
+    DEFINE_PROP_BOOL("ioeventfd", VirtIONet, parent_obj.use_ioeventfd, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 11964ee..3f7a341 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -127,7 +127,8 @@ static void virtio_mmio_start_ioeventfd(VirtIOMMIOProxy *proxy)
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
     int n, r;
 
-    if (proxy->ioeventfd_disabled ||
+    if (!vdev->use_ioeventfd ||
+        proxy->ioeventfd_disabled ||
         proxy->ioeventfd_started) {
         return;
     }
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 3e54e90..d4cb3bf 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -121,6 +121,7 @@ struct VirtIODevice
     bool vm_running;
     VMChangeStateEntry *vmstate;
     char *bus_name;
+    bool use_ioeventfd;
 };
 
 typedef struct VirtioDeviceClass {
-- 
1.8.1.2