From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: [PATCH 25/27] tools/libxl: [RFC] Handle checkpoint records in a libxl migration v2 stream Date: Mon, 15 Jun 2015 14:44:38 +0100 Message-ID: <1434375880-30914-26-git-send-email-andrew.cooper3@citrix.com> References: <1434375880-30914-1-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1434375880-30914-1-git-send-email-andrew.cooper3@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Xen-devel Cc: Wei Liu , Yang Hongyang , Ian Jackson , Ian Campbell , Andrew Cooper List-Id: xen-devel@lists.xenproject.org This is the final bit of untangling for Remus. Signed-off-by: Andrew Cooper CC: Ian Campbell CC: Ian Jackson CC: Wei Liu --- tools/libxl/libxl_create.c | 25 ++++++++++++++++ tools/libxl/libxl_internal.h | 6 ++++ tools/libxl/libxl_stream_read.c | 62 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+) diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c index 7dd7130..ac918bd 100644 --- a/tools/libxl/libxl_create.c +++ b/tools/libxl/libxl_create.c @@ -747,6 +747,27 @@ static int store_libxl_entry(libxl__gc *gc, uint32_t domid, libxl_device_model_version_to_string(b_info->device_model_version)); } +/*----- remus asynchronous checkpoint callback -----*/ + +static void remus_checkpoint_stream_done( + libxl__egc *egc, libxl__domain_create_state *dcs, int rc); + +static void libxl__remus_domain_checkpoint_callback(void *data) +{ + libxl__save_helper_state *shs = data; + libxl__domain_create_state *dcs = CONTAINER_OF(shs, *dcs, shs); + libxl__egc *egc = dcs->shs.egc; + STATE_AO_GC(dcs->ao); + + libxl__stream_read_start_checkpoint(egc, &dcs->srs); +} + +static void remus_checkpoint_stream_done( + libxl__egc *egc, libxl__domain_create_state *dcs, int rc) +{ + libxl__xc_domain_saverestore_async_callback_done(egc, &dcs->shs, rc); +} + /*----- main domain creation -----*/ /* We have a linear control flow; only one event callback is @@ -1008,6 +1029,8 @@ static void domcreate_bootloader_done(libxl__egc *egc, libxl_domain_config *const d_config = dcs->guest_config; const int restore_fd = dcs->restore_fd; libxl__domain_build_state *const state = &dcs->build_state; + libxl__srm_restore_autogen_callbacks *const callbacks = + &dcs->shs.callbacks.restore.a; if (rc) { domcreate_rebuild_done(egc, dcs, rc); @@ -1035,6 +1058,7 @@ static void domcreate_bootloader_done(libxl__egc *egc, } /* Restore */ + callbacks->checkpoint = libxl__remus_domain_checkpoint_callback; rc = libxl__build_pre(gc, domid, d_config, state); if (rc) @@ -1044,6 +1068,7 @@ static void domcreate_bootloader_done(libxl__egc *egc, dcs->srs.fd = restore_fd; dcs->srs.legacy = (dcs->restore_params.stream_version == 1); dcs->srs.completion_callback = domcreate_stream_done; + dcs->srs.checkpoint_callback = remus_checkpoint_stream_done; libxl__stream_read_start(egc, &dcs->srs); return; diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h index bf1c377..e271a0b 100644 --- a/tools/libxl/libxl_internal.h +++ b/tools/libxl/libxl_internal.h @@ -3205,11 +3205,15 @@ struct libxl__stream_read_state { void (*completion_callback)(libxl__egc *egc, libxl__domain_create_state *dcs, int rc); + void (*checkpoint_callback)(libxl__egc *egc, + libxl__domain_create_state *dcs, + int rc); /* Private */ libxl__carefd *v2_carefd; int rc; int joined_rc; bool running; + bool in_checkpoint; libxl__datacopier_state dc; size_t expected_len; libxl_sr_hdr hdr; @@ -3222,6 +3226,8 @@ _hidden void libxl__stream_read_start(libxl__egc *egc, _hidden void libxl__stream_read_continue(libxl__egc *egc, libxl__stream_read_state *stream); +_hidden void libxl__stream_read_start_checkpoint( + libxl__egc *egc, libxl__stream_read_state *stream); _hidden void libxl__stream_read_abort(libxl__egc *egc, libxl__stream_read_state *stream, int rc); diff --git a/tools/libxl/libxl_stream_read.c b/tools/libxl/libxl_stream_read.c index a8cd2c3..09ef0aa 100644 --- a/tools/libxl/libxl_stream_read.c +++ b/tools/libxl/libxl_stream_read.c @@ -80,6 +80,10 @@ static void emulator_padding_done(libxl__egc *egc, libxl__datacopier_state *dc, int onwrite, int errnoval); +/* Error handling for checkpoint mini-loop. */ +static void checkpoint_done(libxl__egc *egc, + libxl__stream_read_state *stream, int rc); + void libxl__stream_read_start(libxl__egc *egc, libxl__stream_read_state *stream) { @@ -162,6 +166,35 @@ void libxl__stream_read_continue(libxl__egc *egc, stream_failed(egc, stream, ret); } +void libxl__stream_read_start_checkpoint(libxl__egc *egc, + libxl__stream_read_state *stream) +{ + libxl__datacopier_state *dc = &stream->dc; + int ret = 0; + + assert(stream->running); + assert(!stream->in_checkpoint); + stream->in_checkpoint = true; + + /* Read a record header. */ + dc->readwhat = "record header"; + dc->readbuf = &stream->rec_hdr; + stream->expected_len = dc->bytes_to_read = sizeof(stream->rec_hdr); + dc->used = 0; + dc->callback = record_header_done; + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + assert(!ret); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + void libxl__stream_read_abort(libxl__egc *egc, libxl__stream_read_state *stream, int rc) { @@ -182,6 +215,15 @@ static void stream_failed(libxl__egc *egc, assert(rc); stream->rc = rc; + /* + *If we are in a checkpoint, pass the failure to libxc, which will come + * back around to us via libxl__xc_domain_restore_done(). + */ + if (stream->in_checkpoint) { + checkpoint_done(egc, stream, rc); + return; + } + if (stream->running) { stream->running = false; stream_done(egc, stream); @@ -194,6 +236,7 @@ static void stream_done(libxl__egc *egc, libxl__domain_create_state *dcs = CONTAINER_OF(stream, *dcs, srs); assert(!stream->running); + assert(!stream->in_checkpoint); if (stream->v2_carefd) libxl__carefd_close(stream->v2_carefd); @@ -452,6 +495,15 @@ static void process_record(libxl__egc *egc, read_emulator_body(egc, stream); break; + case REC_TYPE_CHECKPOINT_END: + if (!stream->in_checkpoint) { + LOG(ERROR, "Unexpected CHECKPOINT_END record in stream"); + ret = ERROR_FAIL; + goto err; + } + checkpoint_done(egc, stream, 0); + break; + default: LOG(ERROR, "Unrecognised record 0x%08x", rec_hdr->type); ret = ERROR_FAIL; @@ -592,6 +644,16 @@ static void emulator_padding_done(libxl__egc *egc, stream_failed(egc, stream, ret); } +static void checkpoint_done(libxl__egc *egc, + libxl__stream_read_state *stream, int rc) +{ + libxl__domain_create_state *dcs = CONTAINER_OF(stream, *dcs, srs); + + assert(stream->in_checkpoint); + stream->in_checkpoint = false; + stream->checkpoint_callback(egc, dcs, rc); +} + /* * Local variables: * mode: C -- 1.7.10.4