Postcopy live-migration feature requires the application to
not populate the guest memory. As the vhost library cannot
prevent the application to that (e.g. preventing the
application to call mlockall()), the feature is disabled by
default.
The application should only enable the feature if it does not
force the guest memory to be populated.
In case the user passes the RTE_VHOST_USER_POSTCOPY_SUPPORT
flag at registration but the feature was not compiled,
registration fails.
For the same reason, postcopy and dequeue zero copy features
are not compatible, so don't advertize postcopy support if
dequeue zero copy is requested.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Enabling this flag with these Qemu version results in Qemu being blocked
when multiple queue pairs are declared.
Enabling this flag with these Qemu version results in Qemu being blocked
when multiple queue pairs are declared.
+ - ``RTE_VHOST_USER_POSTCOPY_SUPPORT``
+
+ Postcopy live-migration support will be enabled when this flag is set.
+ It is disabled by default.
+
+ Enabling this flag should only be done when the calling application does
+ not pre-fault the guest shared memory, otherwise migration would fail.
+
* ``rte_vhost_driver_set_features(path, features)``
This function sets the feature bits the vhost-user driver supports. The
* ``rte_vhost_driver_set_features(path, features)``
This function sets the feature bits the vhost-user driver supports. The
#define RTE_VHOST_USER_NO_RECONNECT (1ULL << 1)
#define RTE_VHOST_USER_DEQUEUE_ZERO_COPY (1ULL << 2)
#define RTE_VHOST_USER_IOMMU_SUPPORT (1ULL << 3)
#define RTE_VHOST_USER_NO_RECONNECT (1ULL << 1)
#define RTE_VHOST_USER_DEQUEUE_ZERO_COPY (1ULL << 2)
#define RTE_VHOST_USER_IOMMU_SUPPORT (1ULL << 3)
+#define RTE_VHOST_USER_POSTCOPY_SUPPORT (1ULL << 4)
/** Protocol features. */
#ifndef VHOST_USER_PROTOCOL_F_MQ
/** Protocol features. */
#ifndef VHOST_USER_PROTOCOL_F_MQ
uint64_t supported_features;
uint64_t features;
uint64_t supported_features;
uint64_t features;
+ uint64_t protocol_features;
+
/*
* Device id to identify a specific backend device.
* It's set to -1 for the default software implementation.
/*
* Device id to identify a specific backend device.
* It's set to -1 for the default software implementation.
did = vsocket->vdpa_dev_id;
vdpa_dev = rte_vdpa_get_device(did);
if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
did = vsocket->vdpa_dev_id;
vdpa_dev = rte_vdpa_get_device(did);
if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
- *protocol_features = VHOST_USER_PROTOCOL_FEATURES;
+ *protocol_features = vsocket->protocol_features;
- *protocol_features = VHOST_USER_PROTOCOL_FEATURES
+ *protocol_features = vsocket->protocol_features
& vdpa_protocol_features;
unlock_exit:
& vdpa_protocol_features;
unlock_exit:
vsocket->use_builtin_virtio_net = true;
vsocket->supported_features = VIRTIO_NET_SUPPORTED_FEATURES;
vsocket->features = VIRTIO_NET_SUPPORTED_FEATURES;
vsocket->use_builtin_virtio_net = true;
vsocket->supported_features = VIRTIO_NET_SUPPORTED_FEATURES;
vsocket->features = VIRTIO_NET_SUPPORTED_FEATURES;
+ vsocket->protocol_features = VHOST_USER_PROTOCOL_FEATURES;
- /* Dequeue zero copy can't assure descriptors returned in order */
+ /*
+ * Dequeue zero copy can't assure descriptors returned in order.
+ * Also, it requires that the guest memory is populated, which is
+ * not compatible with postcopy.
+ */
if (vsocket->dequeue_zero_copy) {
vsocket->supported_features &= ~(1ULL << VIRTIO_F_IN_ORDER);
vsocket->features &= ~(1ULL << VIRTIO_F_IN_ORDER);
if (vsocket->dequeue_zero_copy) {
vsocket->supported_features &= ~(1ULL << VIRTIO_F_IN_ORDER);
vsocket->features &= ~(1ULL << VIRTIO_F_IN_ORDER);
+
+ RTE_LOG(INFO, VHOST_CONFIG,
+ "Dequeue zero copy requested, disabling postcopy support\n");
+ vsocket->protocol_features &=
+ ~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
}
if (!(flags & RTE_VHOST_USER_IOMMU_SUPPORT)) {
}
if (!(flags & RTE_VHOST_USER_IOMMU_SUPPORT)) {
vsocket->features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
}
vsocket->features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
}
+ if (!(flags & RTE_VHOST_USER_POSTCOPY_SUPPORT)) {
+ vsocket->protocol_features &=
+ ~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
+ } else {
+#ifndef RTE_LIBRTE_VHOST_POSTCOPY
+ RTE_LOG(ERR, VHOST_CONFIG,
+ "Postcopy requested but not compiled\n");
+ ret = -1;
+ goto out_mutex;
+#endif
+ }
+
if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
if (vsocket->reconnect && reconn_tid == 0) {
if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
if (vsocket->reconnect && reconn_tid == 0) {
{
struct virtio_net *dev = *pdev;
uint64_t protocol_features = msg->payload.u64;
{
struct virtio_net *dev = *pdev;
uint64_t protocol_features = msg->payload.u64;
- if (protocol_features & ~VHOST_USER_PROTOCOL_FEATURES) {
+ uint64_t slave_protocol_features = 0;
+
+ rte_vhost_driver_get_protocol_features(dev->ifname,
+ &slave_protocol_features);
+ if (protocol_features & ~slave_protocol_features) {
RTE_LOG(ERR, VHOST_CONFIG,
"(%d) received invalid protocol features.\n",
dev->vid);
RTE_LOG(ERR, VHOST_CONFIG,
"(%d) received invalid protocol features.\n",
dev->vid);