[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 20/27] tools/libxl: Infrastructure for writing a v2 stream
On 06/15/2015 09:44 PM, Andrew Cooper wrote: [...] + +static void stream_success(libxl__egc *egc, + libxl__stream_write_state *stream); +static void stream_failed(libxl__egc *egc, + libxl__stream_write_state *stream, int ret); +static void stream_done(libxl__egc *egc, + libxl__stream_write_state *stream); + +static void check_stream_finished(libxl__egc *egc, + libxl__domain_suspend_state *dcs, s/dcs/dss/ + int rc, const char *what); + +/* Event callbacks for plain VM. */ +static void stream_header_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval); +static void libxc_header_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval); +/* libxl__xc_domain_save_done() lives here, event-order wise. */ +static void write_toolstack_record(libxl__egc *egc, + libxl__stream_write_state *stream); +static void toolstack_record_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval); +static void write_emulator_record(libxl__egc *egc, + libxl__stream_write_state *stream); +static void emulator_body_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval); +static void emulator_padding_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval); +static void write_end_record(libxl__egc *egc, + libxl__stream_write_state *stream); +static void end_record_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval); + +void libxl__stream_write_start(libxl__egc *egc, + libxl__stream_write_state *stream) +{ + libxl__datacopier_state *dc = &stream->dc; + STATE_AO_GC(stream->ao); + struct libxl_sr_hdr hdr = { 0 }; + int ret = 0; + + assert(!stream->running); + stream->running = true; + + memset(dc, 0, sizeof(*dc)); + dc->readwhat = ""; + dc->copywhat = "suspend header"; + dc->writewhat = "save/migration stream"; + dc->ao = ao; + dc->readfd = -1; + dc->writefd = stream->fd; + dc->maxsz = INT_MAX; + dc->bytes_to_read = INT_MAX; + dc->callback = stream_header_done; + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + hdr.ident = htobe64(RESTORE_STREAM_IDENT); + hdr.version = htobe32(RESTORE_STREAM_VERSION); + hdr.options = htobe32(0); + + libxl__datacopier_prefixdata(egc, dc, &hdr, sizeof(hdr)); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +void libxl__stream_write_abort(libxl__egc *egc, + libxl__stream_write_state *stream, int rc) +{ + stream_failed(egc, stream, rc); +} + +static void stream_success(libxl__egc *egc, libxl__stream_write_state *stream) +{ + stream->rc = 0; + stream->running = false; + + stream_done(egc, stream); +} + +static void stream_failed(libxl__egc *egc, + libxl__stream_write_state *stream, int rc) +{ + assert(rc); + stream->rc = rc; + + if (stream->running) { + stream->running = false; + stream_done(egc, stream); + } +} + +static void stream_done(libxl__egc *egc, + libxl__stream_write_state *stream) +{ + libxl__domain_suspend_state *dss = CONTAINER_OF(stream, *dss, sws); + + assert(!stream->running); + + check_stream_finished(egc, dss, stream->rc, "stream"); +} + +static void check_stream_finished(libxl__egc *egc, + libxl__domain_suspend_state *dss, + int rc, const char *what) +{ + libxl__stream_write_state *stream = &dss->sws; + STATE_AO_GC(dss->ao); + + LOG(INFO, "Task '%s' joining (rc %d)", what, rc); + + if (rc && !stream->joined_rc) { + bool skip = false; + /* First reported failure from joining tasks. Tear everything down */ + stream->joined_rc = rc; + + if (libxl__stream_write_inuse(&dss->sws)) { + skip = true; + libxl__stream_write_abort(egc, &dss->sws, rc); + } + + if (libxl__save_helper_inuse(&dss->shs)) { + skip = true; + libxl__save_helper_abort(egc, &dss->shs); + } + + /* There is at least one more active task to join - wait for its + callback */ + if ( skip ) + return; + } + + if (libxl__stream_write_inuse(&dss->sws)) + LOG(DEBUG, "stream still in use"); + else if (libxl__save_helper_inuse(&dss->shs)) + LOG(DEBUG, "save/restore still in use"); + else { + LOG(INFO, "Join complete: result %d", stream->joined_rc); + stream->completion_callback(egc, dss, stream->joined_rc); + } +} + +static void stream_header_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval) +{ + libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, dc); + STATE_AO_GC(stream->ao); + struct libxl_sr_rec_hdr rec = { REC_TYPE_LIBXC_CONTEXT, 0 }; + int ret = 0; + + if (onwrite || errnoval) { + ret = ERROR_FAIL; + goto err; + } + + dc->copywhat = "suspend footer"; + dc->writewhat = "save/migration stream"; + dc->callback = libxc_header_done; + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + libxl__datacopier_prefixdata(egc, dc, &rec, sizeof(rec)); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void libxc_header_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval) +{ + libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, dc); + libxl__domain_suspend_state *dss = CONTAINER_OF(stream, *dss, sws); + STATE_AO_GC(stream->ao); + int ret = 0; + + if (onwrite || errnoval) { + ret = ERROR_FAIL; + goto err; + } + + libxl__xc_domain_save(egc, dss); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void __attribute__((used)) +will_be_libxl__xc_domain_save_done(libxl__egc *egc, void *dss_void, + int rc, int retval, int errnoval) +{ + libxl__domain_suspend_state *dss = dss_void; + libxl__stream_write_state *stream = &dss->sws; + STATE_AO_GC(dss->ao); + + if (rc) + goto err; + + if (retval) { + LOGEV(ERROR, errnoval, "saving domain: %s", + dss->guest_responded ? + "domain responded to suspend request" : + "domain did not respond to suspend request"); + if ( !dss->guest_responded ) + rc = ERROR_GUEST_TIMEDOUT; + else + rc = ERROR_FAIL; + goto err; + } + + write_toolstack_record(egc, stream); + return; + + err: + assert(rc); + check_stream_finished(egc, dss, rc, "save/restore helper"); +} + +static void write_toolstack_record(libxl__egc *egc, + libxl__stream_write_state *stream) +{ + libxl__domain_suspend_state *dss = CONTAINER_OF(stream, *dss, sws); + libxl__datacopier_state *dc = &stream->dc; + STATE_AO_GC(stream->ao); + struct libxl_sr_rec_hdr rec = { REC_TYPE_XENSTORE_DATA, 0 }; + int ret = 0; + uint8_t *toolstack_buf = NULL; /* We must free this. */ + uint32_t toolstack_len, padding_len; + + ret = libxl__toolstack_save(dss->domid, &toolstack_buf, + &toolstack_len, dss); + if (ret) + goto err; + + dc->copywhat = "toolstack record"; + dc->writewhat = "save/migration stream"; + dc->callback = toolstack_record_done; + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + rec.length = toolstack_len; + + libxl__datacopier_prefixdata(egc, dc, &rec, sizeof(rec)); + libxl__datacopier_prefixdata(egc, dc, toolstack_buf, toolstack_len); + + padding_len = ROUNDUP(rec.length, REC_ALIGN_ORDER) - rec.length; + if (padding_len) + libxl__datacopier_prefixdata(egc, dc, zero_padding, padding_len); + + free(toolstack_buf); + return; + + err: + assert(ret); + free(toolstack_buf); + stream_failed(egc, stream, ret); +} + +static void toolstack_record_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval) +{ + libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, dc); + libxl__domain_suspend_state *dss = CONTAINER_OF(stream, *dss, sws); + STATE_AO_GC(stream->ao); + int ret = 0; + + if (onwrite || errnoval) { + ret = ERROR_FAIL; + goto err; + } + + if (dss->type == LIBXL_DOMAIN_TYPE_HVM) + write_emulator_record(egc, stream); + else + write_end_record(egc, stream); + + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void write_emulator_record(libxl__egc *egc, + libxl__stream_write_state *stream) +{ + libxl__domain_suspend_state *dss = CONTAINER_OF(stream, *dss, sws); + libxl__datacopier_state *dc = &stream->dc; + STATE_AO_GC(stream->ao); + struct libxl_sr_rec_hdr rec = { REC_TYPE_EMULATOR_CONTEXT, 0 }; + struct libxl_sr_emulator_hdr ehdr = { 0 }; + struct stat st; + int ret = 0; + uint32_t qemu_state_len; + + assert(dss->type == LIBXL_DOMAIN_TYPE_HVM); + + /* Convenience aliases */ + const char *const filename = dss->dm_savefile; + const uint32_t domid = dss->domid; + + switch(libxl__device_model_version_running(gc, domid)) { + case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL: + ehdr.id = EMULATOR_QEMU_TRADITIONAL; + break; + + case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN: + ehdr.id = EMULATOR_QEMU_UPSTREAM; + break; + + default: + ret = ERROR_FAIL; + goto err; + } + + ret = libxl__domain_suspend_device_model(gc, dss); + if (ret) + goto err; + + dc->readwhat = GCSPRINTF("qemu save file %s", filename); + dc->copywhat = "emulator record"; + dc->writewhat = "save/migration stream"; + dc->callback = emulator_body_done; + + dc->readfd = open(filename, O_RDONLY); + if (dc->readfd < 0) { + LOGE(ERROR, "unable to open %s", dc->readwhat); + goto err; + } + + if (fstat(dc->readfd, &st)) + { + LOGE(ERROR, "unable to fstat %s", dc->readwhat); + goto err; + } + + if (!S_ISREG(st.st_mode)) { + LOG(ERROR, "%s is not a plain file!", dc->readwhat); + goto err; + } + + qemu_state_len = st.st_size; + rec.length = qemu_state_len + sizeof(ehdr); + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + libxl__datacopier_prefixdata(egc, dc, &rec, sizeof(rec)); + libxl__datacopier_prefixdata(egc, dc, &ehdr, sizeof(ehdr)); + + stream->padding = ROUNDUP(qemu_state_len, REC_ALIGN_ORDER) - qemu_state_len; + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void emulator_body_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval) +{ + libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, dc); + STATE_AO_GC(stream->ao); + int ret = 0; + + if (onwrite || errnoval) { + ret = ERROR_FAIL; + goto err; + } + + dc->readwhat = ""; + dc->readfd = -1; + + if (stream->padding) { + assert(stream->padding < (1U << REC_ALIGN_ORDER)); + + dc->copywhat = "emulator padding"; + dc->writewhat = "save/migration stream"; + dc->callback = emulator_padding_done; + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + libxl__datacopier_prefixdata(egc, dc, zero_padding, stream->padding); + return; + } + + emulator_padding_done(egc, dc, 0, 0); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void emulator_padding_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval) +{ + libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, dc); + STATE_AO_GC(stream->ao); + int ret = 0; + + if (onwrite || errnoval) { + ret = ERROR_FAIL; + goto err; + } + + write_end_record(egc, stream); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void write_end_record(libxl__egc *egc, + libxl__stream_write_state *stream) +{ + libxl__datacopier_state *dc = &stream->dc; + STATE_AO_GC(stream->ao); + struct libxl_sr_rec_hdr rec = { REC_TYPE_END, 0 }; + int ret = 0; + + dc->copywhat = "suspend footer"; + dc->writewhat = "save/migration stream"; + dc->callback = end_record_done; + + ret = libxl__datacopier_start(dc); + if (ret) + goto err; + + libxl__datacopier_prefixdata(egc, dc, &rec, sizeof(rec)); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +static void end_record_done(libxl__egc *egc, + libxl__datacopier_state *dc, + int onwrite, int errnoval) +{ + libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, dc); + STATE_AO_GC(stream->ao); + int ret = 0; + + if (onwrite || errnoval) { + ret = ERROR_FAIL; + goto err; + } + + stream_success(egc, stream); + return; + + err: + assert(ret); + stream_failed(egc, stream, ret); +} + +/* + * Local variables: + * mode: C + * c-basic-offset: 4 + * indent-tabs-mode: nil + * End: + */ -- Thanks, Yang. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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