qemu:virtio-net: Add a virtqueue for control commands from the guest (Alex Williamson)

This will be used for RX mode, MAC table, VLAN table control, etc...

The control transaction consists of one or more "out" sg entries and
one or more "in" sg entries.  The first out entry contains a header
defining the class and command.  Additional out entries may provide
data for the command.  A response via the ack entry is required
and the guest will typically be waiting for it.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6536 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 33 insertions, 1 deletions

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 073f23a279..5a8287bdcc 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -25,6 +25,7 @@ typedef struct VirtIONet
     uint16_t status;
     VirtQueue *rx_vq;
     VirtQueue *tx_vq;
+    VirtQueue *ctrl_vq;
     VLANClientState *vc;
     QEMUTimer *tx_timer;
     int tx_timer_active;
@@ -79,7 +80,9 @@ static void virtio_net_set_link_status(VLANClientState *vc)
 
 static uint32_t virtio_net_get_features(VirtIODevice *vdev)
 {
-    uint32_t features = (1 << VIRTIO_NET_F_MAC) | (1 << VIRTIO_NET_F_STATUS);
+    uint32_t features = (1 << VIRTIO_NET_F_MAC) |
+                        (1 << VIRTIO_NET_F_STATUS) |
+                        (1 << VIRTIO_NET_F_CTRL_VQ);
 
     return features;
 }
@@ -91,6 +94,34 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
     n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
 }
 
+static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+{
+    struct virtio_net_ctrl_hdr ctrl;
+    virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+    VirtQueueElement elem;
+
+    while (virtqueue_pop(vq, &elem)) {
+        if ((elem.in_num < 1) || (elem.out_num < 1)) {
+            fprintf(stderr, "virtio-net ctrl missing headers\n");
+            exit(1);
+        }
+
+        if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
+            elem.out_sg[elem.in_num - 1].iov_len < sizeof(status)) {
+            fprintf(stderr, "virtio-net ctrl header not in correct element\n");
+            exit(1);
+        }
+
+        ctrl.class = ldub_p(elem.out_sg[0].iov_base);
+        ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
+
+        stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
+
+        virtqueue_push(vq, &elem, sizeof(status));
+        virtio_notify(vdev, vq);
+    }
+}
+
 /* RX */
 
 static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
@@ -356,6 +387,7 @@ void virtio_net_init(PCIBus *bus, NICInfo *nd, int devfn)
     n->vdev.set_features = virtio_net_set_features;
     n->rx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_rx);
     n->tx_vq = virtio_add_queue(&n->vdev, 256, virtio_net_handle_tx);
+    n->ctrl_vq = virtio_add_queue(&n->vdev, 16, virtio_net_handle_ctrl);
     memcpy(n->mac, nd->macaddr, ETH_ALEN);
     n->status = VIRTIO_NET_S_LINK_UP;
     n->vc = qemu_new_vlan_client(nd->vlan, nd->model, nd->name,