Commit c639187e authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Michael S. Tsirkin
Browse files

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: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 0185cfb3

contrib/libvhost-user/libvhost-user.c

+23 −0
Original line number Diff line number Diff line
@@ -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);

contrib/libvhost-user/libvhost-user.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

docs/interop/vhost-user.txt

+12 −0
Original line number Diff line number Diff line
@@ -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

-------------------

hw/virtio/vhost-user.c

+1 −0
Original line number Diff line number Diff line
@@ -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;