[Qemu-devel] [RFC PATCH v2 4/4] net: port virtio net onto glib

[Liu Ping Fan <qemulist@gmail.com>]

From: Liu Ping Fan <pingfank@linux.vnet.ibm.com>

Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
---
 hw/virtio-net.c |  165 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/virtio.c     |    6 ++
 hw/virtio.h     |    2 +
 3 files changed, 173 insertions(+), 0 deletions(-)

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index bb2c26c..c6ebd68 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -61,6 +61,7 @@ typedef struct VirtIONet
     uint8_t nouni;
     uint8_t nobcast;
     uint8_t vhost_started;
+    uint8_t dataplane_started;
     struct {
         int in_use;
         int first_multi;
@@ -98,6 +99,9 @@ static VirtIOFeature feature_sizes[] = {
     {}
 };
 
+static void virtio_net_data_plane_start(VirtIONet *n);
+static void virtio_net_data_plane_stop(VirtIONet *n);
+
 static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc)
 {
     VirtIONet *n = qemu_get_nic_opaque(nc);
@@ -150,6 +154,12 @@ static bool virtio_net_started(VirtIONet *n, uint8_t status)
         (n->status & VIRTIO_NET_S_LINK_UP) && n->vdev.vm_running;
 }
 
+#if 0
+static void virtio_net_data_plane_status(VirtIONet *n, uint8_t status)
+{
+}
+#endif
+
 static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
 {
     NetClientState *nc = qemu_get_queue(n->nic);
@@ -197,6 +207,19 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
 
     virtio_net_vhost_status(n, status);
 
+    if (virtio_net_started(n, status) && !n->vhost_started) {
+        /* use data plane */
+        if (!n->dataplane_started) {
+            virtio_net_data_plane_start(n);
+            n->dataplane_started = 1;
+            return;
+        } else {
+            virtio_net_data_plane_stop(n);
+            n->dataplane_started = 0;
+            return;
+        }
+    }
+
     for (i = 0; i < n->max_queues; i++) {
         q = &n->vqs[i];
 
@@ -1008,6 +1031,141 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
     }
 }
 
+/* In esseatial, this is ioevent handler */
+static gboolean virtio_net_tx_handler(gpointer user_data)
+{
+    NetClientSource *nsrc = (NetClientSource *)user_data;
+    VirtQueue *vq = (VirtQueue *)nsrc->opaque;
+    VirtIODevice *vdev =  virtio_queue_get_vdev(vq);
+    VirtIONet *n = to_virtio_net(vdev);
+    VirtIONetQueue *q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
+    int32_t ret;
+
+    event_notifier_test_and_clear(virtio_queue_get_host_notifier(vq));
+
+    /* This happens when device was stopped but VCPU wasn't. */
+    if (!n->vdev.vm_running) {
+        return false;
+    }
+    virtio_queue_set_notification(vq, 0);
+    ret = virtio_net_flush_tx(q);
+    if (ret >= n->tx_burst) {
+        event_notifier_set(virtio_queue_get_host_notifier(vq));
+    } else if (ret >= 0) {
+        /* ret == -EBUSY, will rely on cb to re-enable */
+        virtio_queue_set_notification(vq, 1);
+    }
+
+    return true;
+}
+
+static gboolean virtio_net_rx_handler(gpointer user_data)
+{
+    NetClientSource *nsrc = (NetClientSource *)user_data;
+    VirtQueue *vq = (VirtQueue *)nsrc->opaque;
+    VirtIODevice *vdev =  virtio_queue_get_vdev(vq);
+
+    event_notifier_test_and_clear(virtio_queue_get_host_notifier(vq));
+    virtio_net_handle_rx(vdev, vq);
+
+    return true;
+}
+
+/* Detach the org ioeventfd handler */
+static void queue_host_notifier_rebind(VirtQueue *vq)
+{
+    VirtIODevice *vdev =  virtio_queue_get_vdev(vq);
+    VirtIONet *n = to_virtio_net(vdev);
+    VirtIONetQueue *q;
+    NetClientState *nc;
+    NetClientSource *nsrc;
+    nc = &n->nic->ncs[vq2q(virtio_get_queue_index(vq))];
+    q = &n->vqs[vq2q(virtio_get_queue_index(vq))];
+
+    if (vq == q->rx_vq) {
+        nsrc = nc->nsrc[0];
+    } else {
+        nsrc = nc->nsrc[1];
+    }
+    event_notifier_set_handler(virtio_queue_get_host_notifier(vq), NULL);
+    g_source_attach(&nsrc->source, nsrc->ctx);
+}
+
+static void virtio_net_host_notifiers_rebind(VirtIONet *n)
+{
+    VirtIONetQueue *q;
+    int i;
+
+    for (i = 0; i < n->curr_queues; i++) {
+        q = &n->vqs[i];
+        queue_host_notifier_rebind(q->rx_vq);
+        queue_host_notifier_rebind(q->tx_vq);
+    }
+}
+
+static void virtio_net_gsource_init(VirtIONet *n)
+{
+    VirtIONetQueue *q;
+    NetClientState *nc;
+    NetClientSource *nsrc;
+    VirtIODevice *vdev = &n->vdev;
+    int fd;
+    int i;
+
+    for (i = 0; i < n->curr_queues; i++) {
+
+        q = &n->vqs[i];
+        /* rx */
+        nsrc = (NetClientSource *)g_source_new(&net_gsource_funcs,
+                    sizeof(NetClientSource));
+        vdev->binding->set_host_notifier(vdev->binding_opaque, i, true);
+        fd = event_notifier_get_fd(virtio_queue_get_host_notifier(q->rx_vq));
+        nc = &n->nic->ncs[i];
+        net_init_gsource(nc, 0, nsrc, fd, G_IO_IN, NULL, NULL,
+            virtio_net_rx_handler, q->rx_vq);
+        /* tx */
+        nsrc = (NetClientSource *)g_source_new(&net_gsource_funcs,
+                    sizeof(NetClientSource));
+        vdev->binding->set_host_notifier(vdev->binding_opaque, 2*i+1, true);
+        fd = event_notifier_get_fd(virtio_queue_get_host_notifier(q->tx_vq));
+        net_init_gsource(nc, 1, nsrc, fd, G_IO_IN, NULL, NULL,
+            virtio_net_tx_handler, q->tx_vq);
+    }
+}
+
+static void virtio_net_data_plane_start(VirtIONet *n)
+{
+    virtio_net_gsource_init(n);
+    virtio_net_host_notifiers_rebind(n);
+}
+
+static void queue_data_plane_stop(VirtIONetQueue *q)
+{
+    VirtIONet *n = q->n;
+    VirtIODevice *vdev = &n->vdev;
+    int idx;
+    NetClientSource *nsrc;
+    NetClientState *nc;
+    idx = vq2q(virtio_get_queue_index(q->rx_vq));
+    nc = &n->nic->ncs[idx];
+
+    vdev->binding->set_host_notifier(vdev->binding_opaque, 2*idx, false);
+    nsrc = nc->nsrc[0];
+    g_source_destroy(&nsrc->source);
+    vdev->binding->set_host_notifier(vdev->binding_opaque, 2*idx+1, false);
+    nsrc = nc->nsrc[1];
+    g_source_destroy(&nsrc->source);
+}
+
+static void virtio_net_data_plane_stop(VirtIONet *n)
+{
+    int i;
+
+    for (i = 0; i < n->curr_queues; i++) {
+        queue_data_plane_stop(&n->vqs[i]);
+    }
+}
+
 static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIONet *n = to_virtio_net(vdev);
@@ -1274,6 +1432,12 @@ static void virtio_net_cleanup(NetClientState *nc)
     n->nic = NULL;
 }
 
+static void virtio_net_bind_ctx(NetClientState *nc, GMainContext *ctx)
+{
+    g_source_attach(&nc->nsrc[0]->source, ctx);
+    g_source_attach(&nc->nsrc[1]->source, ctx);
+}
+
 static NetClientInfo net_virtio_info = {
     .type = NET_CLIENT_OPTIONS_KIND_NIC,
     .size = sizeof(NICState),
@@ -1281,6 +1445,7 @@ static NetClientInfo net_virtio_info = {
     .receive = virtio_net_receive,
         .cleanup = virtio_net_cleanup,
     .link_status_changed = virtio_net_set_link_status,
+    .bind_ctx = virtio_net_bind_ctx,
 };
 
 static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
diff --git a/hw/virtio.c b/hw/virtio.c
index e259348..d21c4f2 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -658,6 +658,12 @@ int virtio_queue_get_id(VirtQueue *vq)
     return vq - &vdev->vq[0];
 }
 
+VirtIODevice *virtio_queue_get_vdev(VirtQueue *vq)
+{
+    VirtIODevice *vdev = vq->vdev;
+    return vdev;
+}
+
 void virtio_queue_notify_vq(VirtQueue *vq)
 {
     if (vq->vring.desc) {
diff --git a/hw/virtio.h b/hw/virtio.h
index 1e206b8..afe4cf4 100644
--- a/hw/virtio.h
+++ b/hw/virtio.h
@@ -283,6 +283,8 @@ void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx);
 VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
 uint16_t virtio_get_queue_index(VirtQueue *vq);
 int virtio_queue_get_id(VirtQueue *vq);
+VirtIODevice *virtio_queue_get_vdev(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);
-- 
1.7.4.4