From d3dff7a5a1e0a6eff963fabc4d06879d060f34ee Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 12 Mar 2018 17:21:01 +0000 Subject: [PATCH] vhost-user: Add 'VHOST_USER_POSTCOPY_ADVISE' message MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- contrib/libvhost-user/libvhost-user.c | 11 ++++++ 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, 79 insertions(+) diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index 2e358b5bce..37d4228193 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 +857,14 @@ 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 */ + vmsg->size = 0; + return true; /* = send a reply */ +} + static bool vu_process_message(VuDev *dev, VhostUserMsg *vmsg) { @@ -927,6 +936,8 @@ 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..7854e50008 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 + + 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..ceb17b0554 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) { + 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; }