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authorPaolo Bonzini <pbonzini@redhat.com>2017-01-27 16:40:17 +0100
committerMichael S. Tsirkin <mst@redhat.com>2017-02-17 21:52:30 +0200
commitc611c76417f52b335ecaab01c61743e3b705eb7c (patch)
treea8cec626b13d7fccd8f43857745c1a27d6f3db70
parent5eba0404b98294906134c06519c272bfb5f50453 (diff)
virtio: add MemoryListener to cache ring translations
The cached translations are RCU-protected to allow efficient use when processing virtqueues. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.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>
-rw-r--r--hw/virtio/virtio.c105
-rw-r--r--include/hw/virtio/virtio.h1
2 files changed, 103 insertions, 3 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 71e41f66b1..b75cb52fcc 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -60,6 +60,13 @@ typedef struct VRingUsed
VRingUsedElem ring[0];
} VRingUsed;
+typedef struct VRingMemoryRegionCaches {
+ struct rcu_head rcu;
+ MemoryRegionCache desc;
+ MemoryRegionCache avail;
+ MemoryRegionCache used;
+} VRingMemoryRegionCaches;
+
typedef struct VRing
{
unsigned int num;
@@ -68,6 +75,7 @@ typedef struct VRing
hwaddr desc;
hwaddr avail;
hwaddr used;
+ VRingMemoryRegionCaches *caches;
} VRing;
struct VirtQueue
@@ -104,6 +112,51 @@ struct VirtQueue
QLIST_ENTRY(VirtQueue) node;
};
+static void virtio_free_region_cache(VRingMemoryRegionCaches *caches)
+{
+ if (!caches) {
+ return;
+ }
+
+ address_space_cache_destroy(&caches->desc);
+ address_space_cache_destroy(&caches->avail);
+ address_space_cache_destroy(&caches->used);
+ g_free(caches);
+}
+
+static void virtio_init_region_cache(VirtIODevice *vdev, int n)
+{
+ VirtQueue *vq = &vdev->vq[n];
+ VRingMemoryRegionCaches *old = vq->vring.caches;
+ VRingMemoryRegionCaches *new;
+ hwaddr addr, size;
+ int event_size;
+
+ event_size = virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX) ? 2 : 0;
+
+ addr = vq->vring.desc;
+ if (!addr) {
+ return;
+ }
+ new = g_new0(VRingMemoryRegionCaches, 1);
+ size = virtio_queue_get_desc_size(vdev, n);
+ address_space_cache_init(&new->desc, vdev->dma_as,
+ addr, size, false);
+
+ size = virtio_queue_get_used_size(vdev, n) + event_size;
+ address_space_cache_init(&new->used, vdev->dma_as,
+ vq->vring.used, size, true);
+
+ size = virtio_queue_get_avail_size(vdev, n) + event_size;
+ address_space_cache_init(&new->avail, vdev->dma_as,
+ vq->vring.avail, size, false);
+
+ atomic_rcu_set(&vq->vring.caches, new);
+ if (old) {
+ call_rcu(old, virtio_free_region_cache, rcu);
+ }
+}
+
/* virt queue functions */
void virtio_queue_update_rings(VirtIODevice *vdev, int n)
{
@@ -117,6 +170,7 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int n)
vring->used = vring_align(vring->avail +
offsetof(VRingAvail, ring[vring->num]),
vring->align);
+ virtio_init_region_cache(vdev, n);
}
static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc,
@@ -1264,6 +1318,7 @@ void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
vdev->vq[n].vring.desc = desc;
vdev->vq[n].vring.avail = avail;
vdev->vq[n].vring.used = used;
+ virtio_init_region_cache(vdev, n);
}
void virtio_queue_set_num(VirtIODevice *vdev, int n, int num)
@@ -1984,9 +2039,6 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id)
void virtio_cleanup(VirtIODevice *vdev)
{
qemu_del_vm_change_state_handler(vdev->vmstate);
- g_free(vdev->config);
- g_free(vdev->vq);
- g_free(vdev->vector_queues);
}
static void virtio_vmstate_change(void *opaque, int running, RunState state)
@@ -2248,6 +2300,19 @@ void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...)
}
}
+static void virtio_memory_listener_commit(MemoryListener *listener)
+{
+ VirtIODevice *vdev = container_of(listener, VirtIODevice, listener);
+ int i;
+
+ for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
+ if (vdev->vq[i].vring.num == 0) {
+ break;
+ }
+ virtio_init_region_cache(vdev, i);
+ }
+}
+
static void virtio_device_realize(DeviceState *dev, Error **errp)
{
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -2270,6 +2335,9 @@ static void virtio_device_realize(DeviceState *dev, Error **errp)
error_propagate(errp, err);
return;
}
+
+ vdev->listener.commit = virtio_memory_listener_commit;
+ memory_listener_register(&vdev->listener, vdev->dma_as);
}
static void virtio_device_unrealize(DeviceState *dev, Error **errp)
@@ -2292,6 +2360,36 @@ static void virtio_device_unrealize(DeviceState *dev, Error **errp)
vdev->bus_name = NULL;
}
+static void virtio_device_free_virtqueues(VirtIODevice *vdev)
+{
+ int i;
+ if (!vdev->vq) {
+ return;
+ }
+
+ for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
+ VRingMemoryRegionCaches *caches;
+ if (vdev->vq[i].vring.num == 0) {
+ break;
+ }
+ caches = atomic_read(&vdev->vq[i].vring.caches);
+ atomic_set(&vdev->vq[i].vring.caches, NULL);
+ virtio_free_region_cache(caches);
+ }
+ g_free(vdev->vq);
+}
+
+static void virtio_device_instance_finalize(Object *obj)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(obj);
+
+ memory_listener_unregister(&vdev->listener);
+ virtio_device_free_virtqueues(vdev);
+
+ g_free(vdev->config);
+ g_free(vdev->vector_queues);
+}
+
static Property virtio_properties[] = {
DEFINE_VIRTIO_COMMON_FEATURES(VirtIODevice, host_features),
DEFINE_PROP_END_OF_LIST(),
@@ -2418,6 +2516,7 @@ static const TypeInfo virtio_device_info = {
.parent = TYPE_DEVICE,
.instance_size = sizeof(VirtIODevice),
.class_init = virtio_device_class_init,
+ .instance_finalize = virtio_device_instance_finalize,
.abstract = true,
.class_size = sizeof(VirtioDeviceClass),
};
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 0863a254ba..15efcf2057 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -85,6 +85,7 @@ struct VirtIODevice
uint32_t generation;
int nvectors;
VirtQueue *vq;
+ MemoryListener listener;
uint16_t device_id;
bool vm_running;
bool broken; /* device in invalid state, needs reset */