diff mbox

[04/13] virtio: add start_ioeventfd and stop_ioeventfd to VirtioDeviceClass

Message ID 1476100421-28772-5-git-send-email-pbonzini@redhat.com
State New
Headers show

Commit Message

Paolo Bonzini Oct. 10, 2016, 11:53 a.m. UTC 
Allow customization of the start and stop of ioeventfd.  This will
allow direct start of dataplane without passing through the default
ioeventfd handlers, which in turn allows using the dataplane logic
instead of virtio_add_queue_aio.  It will also enable some code
simplification, because the sole entry point to ioeventfd setup
will be virtio_bus_set_host_notifier.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/virtio/virtio-bus.c         | 55 +++++++++++-------------------------
 hw/virtio/virtio.c             | 64 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/virtio/virtio-bus.h |  7 ++++-
 include/hw/virtio/virtio.h     |  4 +++
 4 files changed, 90 insertions(+), 40 deletions(-)

Comments

Cornelia Huck Oct. 19, 2016, 9:17 a.m. UTC | #1 
On Mon, 10 Oct 2016 13:53:32 +0200
Paolo Bonzini <pbonzini@redhat.com> wrote:

> Allow customization of the start and stop of ioeventfd.  This will
> allow direct start of dataplane without passing through the default
> ioeventfd handlers, which in turn allows using the dataplane logic
> instead of virtio_add_queue_aio.  It will also enable some code
> simplification, because the sole entry point to ioeventfd setup
> will be virtio_bus_set_host_notifier.
> 
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/virtio/virtio-bus.c         | 55 +++++++++++-------------------------
>  hw/virtio/virtio.c             | 64 ++++++++++++++++++++++++++++++++++++++++++
>  include/hw/virtio/virtio-bus.h |  7 ++++-
>  include/hw/virtio/virtio.h     |  4 +++
>  4 files changed, 90 insertions(+), 40 deletions(-)
> 

> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 18ce333..3f6005a 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2120,15 +2120,79 @@ static Property virtio_properties[] = {
>      DEFINE_PROP_END_OF_LIST(),
>  };
> 
> +static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)

The _impl postfix looks a bit awkward.
virtio_device_do_start_ioeventfd?
virtio_device_start_ioeventd_internal? (I don't really like these
either...)

Anyway,

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff mbox

Patch

diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
index 97cdb11..1e09f78 100644
--- a/hw/virtio/virtio-bus.c
+++ b/hw/virtio/virtio-bus.c
@@ -153,8 +153,8 @@  void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
  * assign: register/deregister ioeventfd with the kernel
  * set_handler: use the generic ioeventfd handler
  */
-static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
-                                      int n, bool assign, bool set_handler)
+int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
+                               int n, bool assign, bool set_handler)
 {
     VirtIODevice *vdev = virtio_bus_get_device(bus);
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
@@ -185,61 +185,38 @@  static int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
     return r;
 }
 
-void virtio_bus_start_ioeventfd(VirtioBusState *bus)
+int virtio_bus_start_ioeventfd(VirtioBusState *bus)
 {
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
     DeviceState *proxy = DEVICE(BUS(bus)->parent);
-    VirtIODevice *vdev;
-    int n, r;
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+    int r;
 
     if (!k->ioeventfd_assign || k->ioeventfd_disabled(proxy)) {
-        return;
+        return -ENOSYS;
     }
     if (bus->ioeventfd_started || bus->ioeventfd_disabled) {
-        return;
+        return 0;
     }
-    vdev = virtio_bus_get_device(bus);
-    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
-        if (!virtio_queue_get_num(vdev, n)) {
-            continue;
-        }
-        r = set_host_notifier_internal(proxy, bus, n, true, true);
-        if (r < 0) {
-            goto assign_error;
-        }
+    r = vdc->start_ioeventfd(vdev);
+    if (r < 0) {
+        error_report("%s: failed. Fallback to userspace (slower).", __func__);
+        return r;
     }
     bus->ioeventfd_started = true;
-    return;
-
-assign_error:
-    while (--n >= 0) {
-        if (!virtio_queue_get_num(vdev, n)) {
-            continue;
-        }
-
-        r = set_host_notifier_internal(proxy, bus, n, false, false);
-        assert(r >= 0);
-    }
-    error_report("%s: failed. Fallback to userspace (slower).", __func__);
+    return 0;
 }
 
 void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
 {
-    DeviceState *proxy = DEVICE(BUS(bus)->parent);
-    VirtIODevice *vdev;
-    int n, r;
+    VirtIODevice *vdev = virtio_bus_get_device(bus);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
 
     if (!bus->ioeventfd_started) {
         return;
     }
-    vdev = virtio_bus_get_device(bus);
-    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
-        if (!virtio_queue_get_num(vdev, n)) {
-            continue;
-        }
-        r = set_host_notifier_internal(proxy, bus, n, false, false);
-        assert(r >= 0);
-    }
+    vdc->stop_ioeventfd(vdev);
     bus->ioeventfd_started = false;
 }
 
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 18ce333..3f6005a 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2120,15 +2120,79 @@  static Property virtio_properties[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
+static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
+{
+    VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    DeviceState *proxy = DEVICE(BUS(qbus)->parent);
+    int n, r, err;
+
+    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
+        if (!virtio_queue_get_num(vdev, n)) {
+            continue;
+        }
+        r = set_host_notifier_internal(proxy, qbus, n, true, true);
+        if (r < 0) {
+            err = r;
+            goto assign_error;
+        }
+    }
+    return 0;
+
+assign_error:
+    while (--n >= 0) {
+        if (!virtio_queue_get_num(vdev, n)) {
+            continue;
+        }
+
+        r = set_host_notifier_internal(proxy, qbus, n, false, false);
+        assert(r >= 0);
+    }
+    return err;
+}
+
+int virtio_device_start_ioeventfd(VirtIODevice *vdev)
+{
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
+    VirtioBusState *vbus = VIRTIO_BUS(qbus);
+
+    return virtio_bus_start_ioeventfd(vbus);
+}
+
+static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
+{
+    VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    DeviceState *proxy = DEVICE(BUS(qbus)->parent);
+    int n, r;
+
+    for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
+        if (!virtio_queue_get_num(vdev, n)) {
+            continue;
+        }
+        r = set_host_notifier_internal(proxy, qbus, n, false, false);
+        assert(r >= 0);
+    }
+}
+
+void virtio_device_stop_ioeventfd(VirtIODevice *vdev)
+{
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
+    VirtioBusState *vbus = VIRTIO_BUS(qbus);
+
+    virtio_bus_stop_ioeventfd(vbus);
+}
+
 static void virtio_device_class_init(ObjectClass *klass, void *data)
 {
     /* Set the default value here. */
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->realize = virtio_device_realize;
     dc->unrealize = virtio_device_unrealize;
     dc->bus_type = TYPE_VIRTIO_BUS;
     dc->props = virtio_properties;
+    vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl;
+    vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl;
 }
 
 static const TypeInfo virtio_device_info = {
diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
index f74ef1e..aa326e1 100644
--- a/include/hw/virtio/virtio-bus.h
+++ b/include/hw/virtio/virtio-bus.h
@@ -132,10 +132,15 @@  static inline VirtIODevice *virtio_bus_get_device(VirtioBusState *bus)
 }
 
 /* Start the ioeventfd. */
-void virtio_bus_start_ioeventfd(VirtioBusState *bus);
+int virtio_bus_start_ioeventfd(VirtioBusState *bus);
 /* Stop the ioeventfd. */
 void virtio_bus_stop_ioeventfd(VirtioBusState *bus);
 /* Switch from/to the generic ioeventfd handler */
 int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign);
 
+/* This is temporary.  It is only needed because virtio_bus_set_host_notifier
+ * sets ioeventfd_disabled but we will shortly get rid of it.  */
+int set_host_notifier_internal(DeviceState *proxy, VirtioBusState *bus,
+                               int n, bool assign, bool set_handler);
+
 #endif /* VIRTIO_BUS_H */
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 888c8de..343a781 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -125,6 +125,8 @@  typedef struct VirtioDeviceClass {
      * must mask in frontend instead.
      */
     void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
+    int (*start_ioeventfd)(VirtIODevice *vdev);
+    void (*stop_ioeventfd)(VirtIODevice *vdev);
     void (*save)(VirtIODevice *vdev, QEMUFile *f);
     int (*load)(VirtIODevice *vdev, QEMUFile *f, int version_id);
 } VirtioDeviceClass;
@@ -274,6 +276,8 @@  uint16_t virtio_get_queue_index(VirtQueue *vq);
 EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
 void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                 bool with_irqfd);
+int virtio_device_start_ioeventfd(VirtIODevice *vdev);
+void virtio_device_stop_ioeventfd(VirtIODevice *vdev);
 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
 void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                bool set_handler);