vhost: restrict postcopy live-migration enablement

[dpdk.git] / lib / librte_vhost / vhost_user.c

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index d17c3b0..508228a 100644 (file)
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -77,8 +77,12 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
        [VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
        [VHOST_USER_POSTCOPY_ADVISE]  = "VHOST_USER_POSTCOPY_ADVISE",
        [VHOST_USER_POSTCOPY_LISTEN]  = "VHOST_USER_POSTCOPY_LISTEN",
+       [VHOST_USER_POSTCOPY_END]  = "VHOST_USER_POSTCOPY_END",
 };
 
+static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
+static int read_vhost_message(int sockfd, struct VhostUserMsg *msg);
+
 static uint64_t
 get_blk_size(int fd)
 {
@@ -823,7 +827,7 @@ vhost_memory_changed(struct VhostUserMemory *new,
 
 static int
 vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
-                       int main_fd __rte_unused)
+                       int main_fd)
 {
        struct virtio_net *dev = *pdev;
        struct VhostUserMemory *memory = &msg->payload.memory;
@@ -967,11 +971,49 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
                        mmap_offset);
 
                if (dev->postcopy_listening) {
+                       /*
+                        * We haven't a better way right now than sharing
+                        * DPDK's virtual address with Qemu, so that Qemu can
+                        * retrieve the region offset when handling userfaults.
+                        */
+                       memory->regions[i].userspace_addr =
+                               reg->host_user_addr;
+               }
+       }
+       if (dev->postcopy_listening) {
+               /* Send the addresses back to qemu */
+               msg->fd_num = 0;
+               send_vhost_reply(main_fd, msg);
+
+               /* Wait for qemu to acknolwedge it's got the addresses
+                * we've got to wait before we're allowed to generate faults.
+                */
+               VhostUserMsg ack_msg;
+               if (read_vhost_message(main_fd, &ack_msg) <= 0) {
+                       RTE_LOG(ERR, VHOST_CONFIG,
+                               "Failed to read qemu ack on postcopy set-mem-table\n");
+                       goto err_mmap;
+               }
+               if (ack_msg.request.master != VHOST_USER_SET_MEM_TABLE) {
+                       RTE_LOG(ERR, VHOST_CONFIG,
+                               "Bad qemu ack on postcopy set-mem-table (%d)\n",
+                               ack_msg.request.master);
+                       goto err_mmap;
+               }
+
+               /* Now userfault register and we can use the memory */
+               for (i = 0; i < memory->nregions; i++) {
 #ifdef RTE_LIBRTE_VHOST_POSTCOPY
+                       reg = &dev->mem->regions[i];
                        struct uffdio_register reg_struct;
 
-                       reg_struct.range.start = (uint64_t)(uintptr_t)mmap_addr;
-                       reg_struct.range.len = mmap_size;
+                       /*
+                        * Let's register all the mmap'ed area to ensure
+                        * alignment on page boundary.
+                        */
+                       reg_struct.range.start =
+                               (uint64_t)(uintptr_t)reg->mmap_addr;
+                       reg_struct.range.len = reg->mmap_size;
                        reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
 
                        if (ioctl(dev->postcopy_ufd, UFFDIO_REGISTER,
@@ -1280,7 +1322,11 @@ vhost_user_set_protocol_features(struct virtio_net **pdev,
 {
        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);
@@ -1595,6 +1641,25 @@ vhost_user_set_postcopy_listen(struct virtio_net **pdev,
        return VH_RESULT_OK;
 }
 
+static int
+vhost_user_postcopy_end(struct virtio_net **pdev, struct VhostUserMsg *msg,
+                       int main_fd __rte_unused)
+{
+       struct virtio_net *dev = *pdev;
+
+       dev->postcopy_listening = 0;
+       if (dev->postcopy_ufd >= 0) {
+               close(dev->postcopy_ufd);
+               dev->postcopy_ufd = -1;
+       }
+
+       msg->payload.u64 = 0;
+       msg->size = sizeof(msg->payload.u64);
+       msg->fd_num = 0;
+
+       return VH_RESULT_REPLY;
+}
+
 typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
                                        struct VhostUserMsg *msg,
                                        int main_fd);
@@ -1624,6 +1689,7 @@ static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
        [VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
        [VHOST_USER_POSTCOPY_ADVISE] = vhost_user_set_postcopy_advise,
        [VHOST_USER_POSTCOPY_LISTEN] = vhost_user_set_postcopy_listen,
+       [VHOST_USER_POSTCOPY_END] = vhost_user_postcopy_end,
 };