vhost+postcopy: Stash RAMBlock and offset

Stash the RAMBlock and offset for later use looking up
addresses.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/virtio/trace-events

@@ -9,6 +9,7 @@ vhost_section(const char *name, int r) "%s:%d"
 # hw/virtio/vhost-user.c
 vhost_user_postcopy_listen(void) ""
 vhost_user_set_mem_table_postcopy(uint64_t client_addr, uint64_t qhva, int reply_i, int region_i) "client:0x%"PRIx64" for hva: 0x%"PRIx64" reply %d region %d"
+vhost_user_set_mem_table_withfd(int index, const char *name, uint64_t memory_size, uint64_t guest_phys_addr, uint64_t userspace_addr, uint64_t offset) "%d:%s: size:0x%"PRIx64" GPA:0x%"PRIx64" QVA/userspace:0x%"PRIx64" RB offset:0x%"PRIx64
 
 # hw/virtio/virtio.c
 virtqueue_alloc_element(void *elem, size_t sz, unsigned in_num, unsigned out_num) "elem %p size %zd in_num %u out_num %u"

hw/virtio/vhost-user.c

@@ -175,6 +175,15 @@ struct vhost_user {
     NotifierWithReturn postcopy_notifier;
     struct PostCopyFD  postcopy_fd;
     uint64_t           postcopy_client_bases[VHOST_MEMORY_MAX_NREGIONS];
+    /* Length of the region_rb and region_rb_offset arrays */
+    size_t             region_rb_len;
+    /* RAMBlock associated with a given region */
+    RAMBlock         **region_rb;
+    /* The offset from the start of the RAMBlock to the start of the
+     * vhost region.
+     */
+    ram_addr_t        *region_rb_offset;
+
     /* True once we've entered postcopy_listen */
     bool               postcopy_listen;
 };
@@ -362,6 +371,17 @@ static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
         msg.hdr.flags |= VHOST_USER_NEED_REPLY_MASK;
     }
 
+    if (u->region_rb_len < dev->mem->nregions) {
+        u->region_rb = g_renew(RAMBlock*, u->region_rb, dev->mem->nregions);
+        u->region_rb_offset = g_renew(ram_addr_t, u->region_rb_offset,
+                                      dev->mem->nregions);
+        memset(&(u->region_rb[u->region_rb_len]), '\0',
+               sizeof(RAMBlock *) * (dev->mem->nregions - u->region_rb_len));
+        memset(&(u->region_rb_offset[u->region_rb_len]), '\0',
+               sizeof(ram_addr_t) * (dev->mem->nregions - u->region_rb_len));
+        u->region_rb_len = dev->mem->nregions;
+    }
+
     for (i = 0; i < dev->mem->nregions; ++i) {
         struct vhost_memory_region *reg = dev->mem->regions + i;
         ram_addr_t offset;
@@ -372,6 +392,12 @@ static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
                                      &offset);
         fd = memory_region_get_fd(mr);
         if (fd > 0) {
+            trace_vhost_user_set_mem_table_withfd(fd_num, mr->name,
+                                                  reg->memory_size,
+                                                  reg->guest_phys_addr,
+                                                  reg->userspace_addr, offset);
+            u->region_rb_offset[i] = offset;
+            u->region_rb[i] = mr->ram_block;
             msg.payload.memory.regions[fd_num].userspace_addr =
                 reg->userspace_addr;
             msg.payload.memory.regions[fd_num].memory_size  = reg->memory_size;
@@ -380,6 +406,9 @@ static int vhost_user_set_mem_table_postcopy(struct vhost_dev *dev,
             msg.payload.memory.regions[fd_num].mmap_offset = offset;
             assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
             fds[fd_num++] = fd;
+        } else {
+            u->region_rb_offset[i] = 0;
+            u->region_rb[i] = NULL;
         }
     }
 
@@ -1148,6 +1177,11 @@ static int vhost_user_cleanup(struct vhost_dev *dev)
         close(u->slave_fd);
         u->slave_fd = -1;
     }
+    g_free(u->region_rb);
+    u->region_rb = NULL;
+    g_free(u->region_rb_offset);
+    u->region_rb_offset = NULL;
+    u->region_rb_len = 0;
     g_free(u);
     dev->opaque = 0;