virtio: move ioeventfd_started flag to VirtioBusState

This simplifies the code and removes the ioeventfd_started
and ioeventfd_set_started callback.  The only difference is
in how virtio-ccw handles an error---it doesn't disable
ioeventfd forever anymore.  It was the only backend to do
so, and if desired this behavior should be implemented in

virtio-bus.c.

Instead of ioeventfd_started, the ioeventfd_assign callback now
determines whether the virtio bus supports host notifiers.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

5 files changed, 7 insertions, 45 deletions

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index bd051ab..501a5f4 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1190,7 +1190,7 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
     int i, r, e;
 
-    if (!k->ioeventfd_started) {
+    if (!k->ioeventfd_assign) {
         error_report("binding does not support host notifiers");
         r = -ENOSYS;
         goto fail;
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index 3607c29..97cdb11 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -192,10 +192,10 @@ void virtio_bus_start_ioeventfd(VirtioBusState *bus)
     VirtIODevice *vdev;
     int n, r;
 
-    if (!k->ioeventfd_started || k->ioeventfd_started(proxy)) {
+    if (!k->ioeventfd_assign || k->ioeventfd_disabled(proxy)) {
         return;
     }
-    if (bus->ioeventfd_disabled || k->ioeventfd_disabled(proxy)) {
+    if (bus->ioeventfd_started || bus->ioeventfd_disabled) {
         return;
     }
     vdev = virtio_bus_get_device(bus);
@@ -208,7 +208,7 @@ void virtio_bus_start_ioeventfd(VirtioBusState *bus)
             goto assign_error;
         }
     }
-    k->ioeventfd_set_started(proxy, true, false);
+    bus->ioeventfd_started = true;
     return;
 
 assign_error:
@@ -220,18 +220,16 @@ assign_error:
         r = set_host_notifier_internal(proxy, bus, n, false, false);
         assert(r >= 0);
     }
-    k->ioeventfd_set_started(proxy, false, true);
     error_report("%s: failed. Fallback to userspace (slower).", __func__);
 }
 
 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
 {
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
     DeviceState *proxy = DEVICE(BUS(bus)->parent);
     VirtIODevice *vdev;
     int n, r;
 
-    if (!k->ioeventfd_started || !k->ioeventfd_started(proxy)) {
+    if (!bus->ioeventfd_started) {
         return;
     }
     vdev = virtio_bus_get_device(bus);
@@ -242,7 +240,7 @@ void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
         r = set_host_notifier_internal(proxy, bus, n, false, false);
         assert(r >= 0);
     }
-    k->ioeventfd_set_started(proxy, false, false);
+    bus->ioeventfd_started = false;
 }
 
 /*
@@ -254,7 +252,7 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
     DeviceState *proxy = DEVICE(BUS(bus)->parent);
 
-    if (!k->ioeventfd_started) {
+    if (!k->ioeventfd_assign) {
         return -ENOSYS;
     }
     bus->ioeventfd_disabled = assign;
diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
index 12a9e79..04a9655 100644
--- a/hw/virtio/virtio-mmio.c
+++ b/hw/virtio/virtio-mmio.c
@@ -89,25 +89,9 @@ typedef struct {
     uint32_t guest_page_shift;
     /* virtio-bus */
     VirtioBusState bus;
-    bool ioeventfd_started;
     bool format_transport_address;
 } VirtIOMMIOProxy;
 
-static bool virtio_mmio_ioeventfd_started(DeviceState *d)
-{
-    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
-
-    return proxy->ioeventfd_started;
-}
-
-static void virtio_mmio_ioeventfd_set_started(DeviceState *d, bool started,
-                                              bool err)
-{
-    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
-
-    proxy->ioeventfd_started = started;
-}
-
 static bool virtio_mmio_ioeventfd_disabled(DeviceState *d)
 {
     return !kvm_eventfds_enabled();
@@ -547,8 +531,6 @@ static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
     k->save_config = virtio_mmio_save_config;
     k->load_config = virtio_mmio_load_config;
     k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
-    k->ioeventfd_started = virtio_mmio_ioeventfd_started;
-    k->ioeventfd_set_started = virtio_mmio_ioeventfd_set_started;
     k->ioeventfd_disabled = virtio_mmio_ioeventfd_disabled;
     k->ioeventfd_assign = virtio_mmio_ioeventfd_assign;
     k->has_variable_vring_alignment = true;
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index a8cf1e5..f00fc25 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -262,21 +262,6 @@ static int virtio_pci_load_queue(DeviceState *d, int n, QEMUFile *f)
     return 0;
 }
 
-static bool virtio_pci_ioeventfd_started(DeviceState *d)
-{
-    VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
-
-    return proxy->ioeventfd_started;
-}
-
-static void virtio_pci_ioeventfd_set_started(DeviceState *d, bool started,
-                                             bool err)
-{
-    VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
-
-    proxy->ioeventfd_started = started;
-}
-
 static bool virtio_pci_ioeventfd_disabled(DeviceState *d)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
@@ -2531,8 +2516,6 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
     k->device_plugged = virtio_pci_device_plugged;
     k->device_unplugged = virtio_pci_device_unplugged;
     k->query_nvectors = virtio_pci_query_nvectors;
-    k->ioeventfd_started = virtio_pci_ioeventfd_started;
-    k->ioeventfd_set_started = virtio_pci_ioeventfd_set_started;
     k->ioeventfd_disabled = virtio_pci_ioeventfd_disabled;
     k->ioeventfd_assign = virtio_pci_ioeventfd_assign;
 }
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index b13d28d..4d206c8 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -158,7 +158,6 @@ struct VirtIOPCIProxy {
     uint32_t guest_features[2];
     VirtIOPCIQueue vqs[VIRTIO_QUEUE_MAX];
 
-    bool ioeventfd_started;
     VirtIOIRQFD *vector_irqfd;
     int nvqs_with_notifiers;
     VirtioBusState bus;