Hi
On Thu, Mar 8, 2018 at 8:57 PM, Dr. David Alan Gilbert (git)
<dgilb...@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>
> Wire up a notifier to send a VHOST_USER_POSTCOPY_ADVISE
> message on an incoming advise.
>
> Later patches will fill in the behaviour/contents of the
> message.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> contrib/libvhost-user/libvhost-user.c | 14 ++++++++++
> contrib/libvhost-user/libvhost-user.h | 3 +++
> docs/interop/vhost-user.txt | 10 ++++++++
> hw/virtio/vhost-user.c | 48
> +++++++++++++++++++++++++++++++++++
> migration/postcopy-ram.h | 1 +
> migration/savevm.c | 6 +++++
> 6 files changed, 82 insertions(+)
>
> diff --git a/contrib/libvhost-user/libvhost-user.c
> b/contrib/libvhost-user/libvhost-user.c
> index 2e358b5bce..71825d2dde 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -86,6 +86,7 @@ vu_request_to_string(unsigned int req)
> REQ(VHOST_USER_SET_VRING_ENDIAN),
> REQ(VHOST_USER_GET_CONFIG),
> REQ(VHOST_USER_SET_CONFIG),
> + REQ(VHOST_USER_POSTCOPY_ADVISE),
> REQ(VHOST_USER_MAX),
> };
> #undef REQ
> @@ -856,6 +857,17 @@ vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
> return false;
> }
>
> +static bool
> +vu_set_postcopy_advise(VuDev *dev, VhostUserMsg *vmsg)
> +{
> + /* TODO: Open ufd, pass it back in the request
> + * TODO: Add addresses
> + */
> + vmsg->payload.u64 = 0xcafe;
> + vmsg->size = sizeof(vmsg->payload.u64);
Left over? Why send back a u64 with 0xcafe value?
> + return true; /* = send a reply */
> +}
> +
> static bool
> vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
> {
> @@ -927,6 +939,8 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
> return vu_set_config(dev, vmsg);
> case VHOST_USER_NONE:
> break;
> + case VHOST_USER_POSTCOPY_ADVISE:
> + return vu_set_postcopy_advise(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 96db29c4ce..00d78a8810 100644
> --- a/contrib/libvhost-user/libvhost-user.h
> +++ b/contrib/libvhost-user/libvhost-user.h
> @@ -83,6 +83,9 @@ typedef enum VhostUserRequest {
> VHOST_USER_SET_VRING_ENDIAN = 23,
> VHOST_USER_GET_CONFIG = 24,
> VHOST_USER_SET_CONFIG = 25,
> + VHOST_USER_CREATE_CRYPTO_SESSION = 26,
> + VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
> + VHOST_USER_POSTCOPY_ADVISE = 28,
> VHOST_USER_MAX
> } VhostUserRequest;
>
> diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
> index 91a572d781..acc4186c79 100644
> --- a/docs/interop/vhost-user.txt
> +++ b/docs/interop/vhost-user.txt
> @@ -699,6 +699,16 @@ Master message types
> feature has been successfully negotiated.
> It's a required feature for crypto devices.
>
> + * VHOST_USER_POSTCOPY_ADVISE
> + Id: 28
> + Master payload: N/A
> + Slave payload: userfault fd + u64
If the reply is modified, update doc as well
> +
> + When VHOST_USER_PROTOCOL_F_PAGEFAULT is supported, the
> + master advises slave that a migration with postcopy enabled is
> underway,
> + the slave must open a userfaultfd for later use.
> + Note that at this stage the migration is still in precopy mode.
> +
> Slave message types
> -------------------
>
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index aab35c4845..431858b219 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -78,6 +78,7 @@ typedef enum VhostUserRequest {
> VHOST_USER_SET_CONFIG = 25,
> VHOST_USER_CREATE_CRYPTO_SESSION = 26,
> VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
> + VHOST_USER_POSTCOPY_ADVISE = 28,
> VHOST_USER_MAX
> } VhostUserRequest;
>
> @@ -795,6 +796,50 @@ out:
> return ret;
> }
>
> +/*
> + * Called at the start of an inbound postcopy on reception of the
> + * 'advise' command.
> + */
> +static int vhost_user_postcopy_advise(struct vhost_dev *dev, Error **errp)
> +{
> + struct vhost_user *u = dev->opaque;
> + CharBackend *chr = u->chr;
> + int ufd;
> + VhostUserMsg msg = {
> + .hdr.request = VHOST_USER_POSTCOPY_ADVISE,
> + .hdr.flags = VHOST_USER_VERSION,
> + };
> +
> + if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
> + error_setg(errp, "Failed to send postcopy_advise to vhost");
> + return -1;
> + }
> +
> + if (vhost_user_read(dev, &msg) < 0) {
> + error_setg(errp, "Failed to get postcopy_advise reply from vhost");
> + return -1;
> + }
> +
> + if (msg.hdr.request != VHOST_USER_POSTCOPY_ADVISE) {
> + error_setg(errp, "Unexpected msg type. Expected %d received %d",
> + VHOST_USER_POSTCOPY_ADVISE, msg.hdr.request);
> + return -1;
> + }
> +
> + if (msg.hdr.size != sizeof(msg.payload.u64)) {
> + error_setg(errp, "Received bad msg size.");
> + return -1;
> + }
> + ufd = qemu_chr_fe_get_msgfd(chr);
> + if (ufd < 0) {
> + error_setg(errp, "%s: Failed to get ufd", __func__);
> + return -1;
> + }
> +
> + /* TODO: register ufd with userfault thread */
> + return 0;
> +}
> +
> static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
> void *opaque)
> {
> @@ -814,6 +859,9 @@ static int
> vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
> }
> break;
>
> + case POSTCOPY_NOTIFY_INBOUND_ADVISE:
> + return vhost_user_postcopy_advise(dev, pnd->errp);
> +
> default:
> /* We ignore notifications we don't know */
> break;
> diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
> index 2e879bbacb..0421c98d57 100644
> --- a/migration/postcopy-ram.h
> +++ b/migration/postcopy-ram.h
> @@ -130,6 +130,7 @@ void postcopy_infrastructure_init(void);
> */
> enum PostcopyNotifyReason {
> POSTCOPY_NOTIFY_PROBE = 0,
> + POSTCOPY_NOTIFY_INBOUND_ADVISE,
> };
>
> struct PostcopyNotifyData {
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 358c5b51e2..1f2bf12a28 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1386,6 +1386,7 @@ static int
> loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
> {
> PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
> uint64_t remote_pagesize_summary, local_pagesize_summary, remote_tps;
> + Error *local_err = NULL;
>
> trace_loadvm_postcopy_handle_advise();
> if (ps != POSTCOPY_INCOMING_NONE) {
> @@ -1451,6 +1452,11 @@ static int
> loadvm_postcopy_handle_advise(MigrationIncomingState *mis,
> return -1;
> }
>
> + if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_ADVISE, &local_err)) {
> + error_report_err(local_err);
> + return -1;
> + }
> +
> if (ram_postcopy_incoming_init(mis)) {
> return -1;
> }
> --
> 2.14.3
>
>
--
Marc-André Lureau
