vhost-user: Add VHOST_USER_POSTCOPY_END message

This message is sent just before the end of postcopy to get the
client to stop using userfault since we wont respond to any more
requests.  It should close userfaultfd so that any other pages
get mapped to the backing file automatically by the kernel, since
at this point we know we've received everything.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@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>

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index 5feed520983d3af141cf86e4f6e8941738d55916..504ff5ea59fd62a50aa4ab0d92ce9301fc3a37b4 100644 (file)
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -99,6 +99,7 @@ vu_request_to_string(unsigned int req)
         REQ(VHOST_USER_SET_CONFIG),
         REQ(VHOST_USER_POSTCOPY_ADVISE),
         REQ(VHOST_USER_POSTCOPY_LISTEN),
+        REQ(VHOST_USER_POSTCOPY_END),
         REQ(VHOST_USER_MAX),
     };
 #undef REQ
@@ -1094,6 +1095,26 @@ vu_set_postcopy_listen(VuDev *dev, VhostUserMsg *vmsg)
     vmsg->payload.u64 = 0; /* Success */
     return true;
 }
+
+static bool
+vu_set_postcopy_end(VuDev *dev, VhostUserMsg *vmsg)
+{
+    DPRINT("%s: Entry\n", __func__);
+    dev->postcopy_listening = false;
+    if (dev->postcopy_ufd > 0) {
+        close(dev->postcopy_ufd);
+        dev->postcopy_ufd = -1;
+        DPRINT("%s: Done close\n", __func__);
+    }
+
+    vmsg->fd_num = 0;
+    vmsg->payload.u64 = 0;
+    vmsg->size = sizeof(vmsg->payload.u64);
+    vmsg->flags = VHOST_USER_VERSION |  VHOST_USER_REPLY_MASK;
+    DPRINT("%s: exit\n", __func__);
+    return true;
+}
+
 static bool
 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
 {
@@ -1169,6 +1190,8 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
         return vu_set_postcopy_advise(dev, vmsg);
     case VHOST_USER_POSTCOPY_LISTEN:
         return vu_set_postcopy_listen(dev, vmsg);
+    case VHOST_USER_POSTCOPY_END:
+        return vu_set_postcopy_end(dev, vmsg);
     default:
         vmsg_close_fds(vmsg);
         vu_panic(dev, "Unhandled request: %d", vmsg->request);

diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h
index ed505cf0c1f48a899320a64619f2faad8d4c37af..79f7a53ee84575d192b94123dc82ae256ffa6ac5 100644 (file)
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -87,6 +87,7 @@ typedef enum VhostUserRequest {
     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
     VHOST_USER_POSTCOPY_ADVISE  = 28,
     VHOST_USER_POSTCOPY_LISTEN  = 29,
+    VHOST_USER_POSTCOPY_END     = 30,
     VHOST_USER_MAX
 } VhostUserRequest;
 

diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index e295ef12cad3d1f40272653ba3de1433a05b0b7f..c058c407df71b0cc60543b04f70818baa04a0cfb 100644 (file)
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -729,6 +729,18 @@ Master message types
       This is always sent sometime after a VHOST_USER_POSTCOPY_ADVISE, and
       thus only when VHOST_USER_PROTOCOL_F_PAGEFAULT is supported.
 
+ * VHOST_USER_POSTCOPY_END
+      Id: 30
+      Slave payload: u64
+
+      Master advises that postcopy migration has now completed.  The
+      slave must disable the userfaultfd. The response is an acknowledgement
+      only.
+      When VHOST_USER_PROTOCOL_F_PAGEFAULT is supported, this message
+      is sent at the end of the migration, after VHOST_USER_POSTCOPY_LISTEN
+      was previously sent.
+      The value returned is an error indication; 0 is success.
+
 Slave message types
 -------------------
 

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index a785aefd3e744bb1dd01089058349a88688c9d1b..230f2f9d55482d208979271bf24d493260ccdb9a 100644 (file)
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -82,6 +82,7 @@ typedef enum VhostUserRequest {
     VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
     VHOST_USER_POSTCOPY_ADVISE  = 28,
     VHOST_USER_POSTCOPY_LISTEN  = 29,
+    VHOST_USER_POSTCOPY_END     = 30,
     VHOST_USER_MAX
 } VhostUserRequest;