virtio-net: dynamic network offloads configuration
Virtio-net driver currently negotiates network offloads
on startup via features mechanism and have no ability to
disable and re-enable offloads later.
This patch introduced a new control command that allows
to configure device network offloads state dynamically.
The patch also introduces a new feature flag
VIRTIO_NET_F_CTRL_GUEST_OFFLOADS.
Signed-off-by: Dmitry Fleytman <dfleytma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20130520081814.GA8162@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index bed0822..1ea9556 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -359,6 +359,34 @@
return features;
}
+static void virtio_net_apply_guest_offloads(VirtIONet *n)
+{
+ tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,
+ !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_CSUM)),
+ !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO4)),
+ !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_TSO6)),
+ !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_ECN)),
+ !!(n->curr_guest_offloads & (1ULL << VIRTIO_NET_F_GUEST_UFO)));
+}
+
+static uint64_t virtio_net_guest_offloads_by_features(uint32_t features)
+{
+ static const uint64_t guest_offloads_mask =
+ (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
+ (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
+ (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
+ (1ULL << VIRTIO_NET_F_GUEST_ECN) |
+ (1ULL << VIRTIO_NET_F_GUEST_UFO);
+
+ return guest_offloads_mask & features;
+}
+
+static inline uint64_t virtio_net_supported_guest_offloads(VirtIONet *n)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(n);
+ return virtio_net_guest_offloads_by_features(vdev->guest_features);
+}
+
static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
{
VirtIONet *n = VIRTIO_NET(vdev);
@@ -369,12 +397,9 @@
virtio_net_set_mrg_rx_bufs(n, !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF)));
if (n->has_vnet_hdr) {
- tap_set_offload(qemu_get_subqueue(n->nic, 0)->peer,
- (features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
- (features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
- (features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
- (features >> VIRTIO_NET_F_GUEST_ECN) & 1,
- (features >> VIRTIO_NET_F_GUEST_UFO) & 1);
+ n->curr_guest_offloads =
+ virtio_net_guest_offloads_by_features(features);
+ virtio_net_apply_guest_offloads(n);
}
for (i = 0; i < n->max_queues; i++) {
@@ -420,6 +445,43 @@
return VIRTIO_NET_OK;
}
+static int virtio_net_handle_offloads(VirtIONet *n, uint8_t cmd,
+ struct iovec *iov, unsigned int iov_cnt)
+{
+ VirtIODevice *vdev = VIRTIO_DEVICE(n);
+ uint64_t offloads;
+ size_t s;
+
+ if (!((1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) & vdev->guest_features)) {
+ return VIRTIO_NET_ERR;
+ }
+
+ s = iov_to_buf(iov, iov_cnt, 0, &offloads, sizeof(offloads));
+ if (s != sizeof(offloads)) {
+ return VIRTIO_NET_ERR;
+ }
+
+ if (cmd == VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET) {
+ uint64_t supported_offloads;
+
+ if (!n->has_vnet_hdr) {
+ return VIRTIO_NET_ERR;
+ }
+
+ supported_offloads = virtio_net_supported_guest_offloads(n);
+ if (offloads & ~supported_offloads) {
+ return VIRTIO_NET_ERR;
+ }
+
+ n->curr_guest_offloads = offloads;
+ virtio_net_apply_guest_offloads(n);
+
+ return VIRTIO_NET_OK;
+ } else {
+ return VIRTIO_NET_ERR;
+ }
+}
+
static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
struct iovec *iov, unsigned int iov_cnt)
{
@@ -590,6 +652,8 @@
status = virtio_net_handle_vlan_table(n, ctrl.cmd, iov, iov_cnt);
} else if (ctrl.class == VIRTIO_NET_CTRL_MQ) {
status = virtio_net_handle_mq(n, ctrl.cmd, iov, iov_cnt);
+ } else if (ctrl.class == VIRTIO_NET_CTRL_GUEST_OFFLOADS) {
+ status = virtio_net_handle_offloads(n, ctrl.cmd, iov, iov_cnt);
}
s = iov_from_buf(elem.in_sg, elem.in_num, 0, &status, sizeof(status));
@@ -1110,6 +1174,10 @@
qemu_put_be32(f, n->vqs[i].tx_waiting);
}
}
+
+ if ((1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) & vdev->guest_features) {
+ qemu_put_be64(f, n->curr_guest_offloads);
+ }
}
static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
@@ -1167,15 +1235,6 @@
error_report("virtio-net: saved image requires vnet_hdr=on");
return -1;
}
-
- if (n->has_vnet_hdr) {
- tap_set_offload(qemu_get_queue(n->nic)->peer,
- (vdev->guest_features >> VIRTIO_NET_F_GUEST_CSUM) & 1,
- (vdev->guest_features >> VIRTIO_NET_F_GUEST_TSO4) & 1,
- (vdev->guest_features >> VIRTIO_NET_F_GUEST_TSO6) & 1,
- (vdev->guest_features >> VIRTIO_NET_F_GUEST_ECN) & 1,
- (vdev->guest_features >> VIRTIO_NET_F_GUEST_UFO) & 1);
- }
}
if (version_id >= 9) {
@@ -1209,6 +1268,16 @@
}
}
+ if ((1 << VIRTIO_NET_F_CTRL_GUEST_OFFLOADS) & vdev->guest_features) {
+ n->curr_guest_offloads = qemu_get_be64(f);
+ } else {
+ n->curr_guest_offloads = virtio_net_supported_guest_offloads(n);
+ }
+
+ if (peer_has_vnet_hdr(n)) {
+ virtio_net_apply_guest_offloads(n);
+ }
+
virtio_net_set_queues(n);
/* Find the first multicast entry in the saved MAC filter */
