Re: [libvirt] [PATCH V2 13/13] libxl: add migration support

On 13.03.2014 23:11, Jim Fehlig wrote: > This patch adds initial migration support to the libxl driver, > using the VIR_DRV_FEATURE_MIGRATION_PARAMS family of migration > functions. > > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > > V2: > - Now that the libxl driver supports hostdev passthrough, ensure > domain has no hostdevs before migration > - Fail early in libxlDomainMigrateBegin3Params if domain is inactive > - Change name of local variable in libxlDoMigrateSend from 'live' > to 'xl_flags'. > > po/POTFILES.in | 1 + > src/Makefile.am | 3 +- > src/libxl/libxl_conf.h | 6 + > src/libxl/libxl_domain.h | 1 + > src/libxl/libxl_driver.c | 225 +++++++++++++++++ > src/libxl/libxl_migration.c | 598 > ++++++++++++++++++++++++++++++++++++++++++++ > src/libxl/libxl_migration.h | 78 ++++++ > 7 files changed, 911 insertions(+), 1 deletion(-) > > diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c > index 3306dc1..6fc5266 100644 > --- a/src/libxl/libxl_driver.c > +++ b/src/libxl/libxl_driver.c > @@ -4313,6 +4323,216 @@ cleanup: > return ret; > } > > +static char * > +libxlDomainMigrateBegin3Params(virDomainPtr domain, > + virTypedParameterPtr params, > + int nparams, > + char **cookieout ATTRIBUTE_UNUSED, > + int *cookieoutlen ATTRIBUTE_UNUSED, > + unsigned int flags) > +{ > + const char *xmlin = NULL; > + const char *dname = NULL; > + virDomainObjPtr vm = NULL; > + > + virCheckFlags(LIBXL_MIGRATION_FLAGS, NULL); > + if (virTypedParamsValidate(params, nparams, > LIBXL_MIGRATION_PARAMETERS) < 0) > + return NULL; > + > + if (virTypedParamsGetString(params, nparams, > + VIR_MIGRATE_PARAM_DEST_XML, > + &xmlin) < 0 || > + virTypedParamsGetString(params, nparams, > + VIR_MIGRATE_PARAM_DEST_NAME, > + &dname) < 0) I'd expect @dname to be used somewhere...

> + return NULL; > + > + if (!(vm = libxlDomObjFromDomain(domain))) > + return NULL; > + > + if (virDomainMigrateBegin3ParamsEnsureACL(domain->conn, vm->def) > < 0) { > + virObjectUnlock(vm); > + return NULL; > + } > + > + if (!virDomainObjIsActive(vm)) { > + virReportError(VIR_ERR_OPERATION_INVALID, > + "%s", _("domain is not running")); > + virObjectUnlock(vm); > + return NULL; > + } > + > + return libxlDomainMigrationBegin(domain->conn, vm, xmlin); > +} > + > diff --git a/src/libxl/libxl_migration.c b/src/libxl/libxl_migration.c > new file mode 100644 > index 0000000..01023db > --- /dev/null > +++ b/src/libxl/libxl_migration.c > @@ -0,0 +1,598 @@ > +/* > + * libxl_migration.c: methods for handling migration with libxenlight > + * > + * Copyright (C) 2014 SUSE LINUX Products GmbH, Nuernberg, Germany. > + * > + * This library is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * This library is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + * Lesser General Public License for more details. > + * > + * You should have received a copy of the GNU Lesser General Public > + * License along with this library. If not, see > + * <http://www.gnu.org/licenses/>;. > + * > + * Authors: > + * Jim Fehlig <jfehlig(a)suse.com&gt; > + * Chunyan Liu <cyliu(a)suse.com&gt; > + */ > + > +#include <config.h> > + > +#include "internal.h" > +#include "virlog.h" > +#include "virerror.h" > +#include "virconf.h" > +#include "datatypes.h" > +#include "virfile.h" > +#include "viralloc.h" > +#include "viruuid.h" > +#include "vircommand.h" > +#include "virstring.h" > +#include "rpc/virnetsocket.h" > +#include "libxl_domain.h" > +#include "libxl_driver.h" > +#include "libxl_conf.h" > +#include "libxl_migration.h" > + > +#define VIR_FROM_THIS VIR_FROM_LIBXL > + > +typedef struct _libxlMigrateReceiveArgs { > + virConnectPtr conn; > + virDomainObjPtr vm; > + > + /* for freeing listen sockets */ > + virNetSocketPtr *socks; > + size_t nsocks; > +} libxlMigrateReceiveArgs; > + > +static const char libxlMigrateReceiverReady[] = > + "libvirt libxl migration receiver ready, send binary domain data"; > +static const char libxlMigrateReceiverFinish[] = > + "domain received, ready to unpause"; So you're using these to sync source and destination on migration. Kudos for using text protocol not a binary blob. I haven't followed v1 closely, so what was resolution on this? I mean, my concern is if this is extensible. > + > + > +static int > +libxlCheckMessageBanner(int fd, const char *banner, int banner_sz) > +{ > + char buf[banner_sz]; > + int ret = 0; > + > + do { > + ret = saferead(fd, buf, banner_sz); > + } while (ret == -1 && errno == EAGAIN); The @fd is in blocking state, so we should never get EAGAIN here. But it doesn't hurt to check. > + > + if (ret != banner_sz || memcmp(buf, banner, banner_sz)) { > + return -1; > + } > + > + return 0; > +} > + > +static void > +libxlDoMigrateReceive(virNetSocketPtr sock, > + int events ATTRIBUTE_UNUSED, > + void *opaque) > +{ > + libxlMigrateReceiveArgs *data = opaque; > + virConnectPtr conn = data->conn; > + virDomainObjPtr vm = data->vm; > + virNetSocketPtr *socks = data->socks; > + size_t nsocks = data->nsocks; > + libxlDriverPrivatePtr driver = conn->privateData; > + virNetSocketPtr client_sock; > + int recv_fd; > + int len; > + size_t i; > + int ret; > + > + virNetSocketAccept(sock, &client_sock); > + if (client_sock == NULL) { > + virReportError(VIR_ERR_OPERATION_INVALID, "%s", > + _("Fail to accept migration connection")); > + goto cleanup; > + } > + VIR_DEBUG("Accepted migration\n"); > + recv_fd = virNetSocketDupFD(client_sock, true); > + virObjectUnref(client_sock); > + > + len = sizeof(libxlMigrateReceiverReady); > + if (safewrite(recv_fd, libxlMigrateReceiverReady, len) != len) { > + virReportError(VIR_ERR_OPERATION_FAILED, "%s", > + _("Failed to write libxlMigrateReceiverReady")); > + goto cleanup; > + } > + > + virObjectLock(vm); > + ret = libxlDomainStart(driver, vm, false, recv_fd); > + virObjectUnlock(vm); > + > + if (ret < 0) { > + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", > + _("Failed to restore domain with libxenlight")); > + if (!vm->persistent) { > + virDomainObjListRemove(driver->domains, vm); > + vm = NULL; > + } > + goto cleanup; > + } > + > + len = sizeof(libxlMigrateReceiverFinish); > + if (safewrite(recv_fd, libxlMigrateReceiverFinish, len) != len) { > + virReportError(VIR_ERR_OPERATION_FAILED, "%s", > + _("Failed to write > libxlMigrateReceiverFinish")); > + } > + > + /* Remove all listen socks from event handler, and close them. */ > + if (nsocks) { Useless 'if' > + for (i = 0; i < nsocks; i++) { > + virNetSocketUpdateIOCallback(socks[i], 0); > + virNetSocketRemoveIOCallback(socks[i]); > + virNetSocketClose(socks[i]); > + virObjectUnref(socks[i]); > + } > + VIR_FREE(socks); > + } > + > +cleanup: > + VIR_FORCE_CLOSE(recv_fd); > + VIR_FREE(opaque); > + return; > +} > + > +int > +libxlDomainMigrationPrepare(virConnectPtr dconn, > + virDomainDefPtr def, > + const char *uri_in, > + char **uri_out) > +{ > + libxlDriverPrivatePtr driver = dconn->privateData; > + virDomainObjPtr vm = NULL; > + char *hostname = NULL; > + unsigned short port; > + char portstr[100]; > + virURIPtr uri = NULL; > + virNetSocketPtr *socks = NULL; > + size_t nsocks = 0; > + int nsocks_listen = 0; > + libxlMigrateReceiveArgs *args; > + size_t i; > + int ret = -1; > + > + if (!(vm = virDomainObjListAdd(driver->domains, def, > + driver->xmlopt, > + VIR_DOMAIN_OBJ_LIST_ADD_LIVE | > + VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE, > + NULL))) > + goto cleanup; > + > + /* Create socket connection to receive migration data */ > + if (!uri_in) { > + if ((hostname = virGetHostname()) == NULL) > + goto cleanup; > + > + if (STRPREFIX(hostname, "localhost")) { > + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", > + _("hostname on destination resolved to > localhost," > + " but migration requires an FQDN")); > + goto cleanup; > + } > + > + if (virPortAllocatorAcquire(driver->migrationPorts, &port) < 0) > + goto cleanup; > + > + if (virAsprintf(uri_out, "tcp://%s:%d", hostname, port) < 0) > + goto cleanup; > + } else { > + if (!(STRPREFIX(uri_in, "tcp://"))) { > + /* not full URI, add prefix tcp:// */ > + char *tmp; > + if (virAsprintf(&tmp, "tcp://%s", uri_in) < 0) > + goto cleanup; > + uri = virURIParse(tmp); > + VIR_FREE(tmp); > + } else { > + uri = virURIParse(uri_in); > + } > + > + if (uri == NULL) { > + virReportError(VIR_ERR_INVALID_ARG, > + _("unable to parse URI: %s"), > + uri_in); > + goto cleanup; > + } > + > + if (uri->server == NULL) { > + virReportError(VIR_ERR_INVALID_ARG, > + _("missing host in migration URI: %s"), > + uri_in); > + goto cleanup; > + } else { > + hostname = uri->server; > + } > + > + if (uri->port == 0) { > + if (virPortAllocatorAcquire(driver->migrationPorts, > &port) < 0) > + goto cleanup; > + > + } else { > + port = uri->port; > + } > + > + if (virAsprintf(uri_out, "tcp://%s:%d", hostname, port) < 0) > + goto cleanup; > + } > + > + snprintf(portstr, sizeof(portstr), "%d", port); > + > + if (virNetSocketNewListenTCP(hostname, portstr, &socks, &nsocks) > < 0) { > + virReportError(VIR_ERR_OPERATION_FAILED, "%s", > + _("Fail to create socket for incoming > migration")); > + goto cleanup; > + } > + > + if (VIR_ALLOC(args) < 0) > + goto cleanup; > + > + args->conn = dconn; > + args->vm = vm; > + args->socks = socks; > + args->nsocks = nsocks; > + > + for (i = 0; i < nsocks; i++) { > + if (virNetSocketSetBlocking(socks[i], true) < 0) > + continue; > + if (virNetSocketListen(socks[i], 1) < 0) > + continue; > + > + if (virNetSocketAddIOCallback(socks[i], > + 0, > + libxlDoMigrateReceive, > + args, > + NULL) < 0) { > + continue; > + } > + > + virNetSocketUpdateIOCallback(socks[i], > VIR_EVENT_HANDLE_READABLE); > + nsocks_listen++; > + } > + > + if (!nsocks_listen) > + goto cleanup; > + > + ret = 0; > + goto done; > + > +cleanup: > + if (nsocks) { There's no need for this 'if'. > + for (i = 0; i < nsocks; i++) { > + virNetSocketClose(socks[i]); > + virObjectUnref(socks[i]); > + } > + VIR_FREE(socks); > + } > + > +done: > + virURIFree(uri); > + if (vm) > + virObjectUnlock(vm); > + return ret; > +} > + > +int > +libxlDomainMigrationPerform(libxlDriverPrivatePtr driver, > + virDomainObjPtr vm, > + const char *dom_xml ATTRIBUTE_UNUSED, > + const char *dconnuri ATTRIBUTE_UNUSED, > + const char *uri_str, > + const char *dname ATTRIBUTE_UNUSED, > + unsigned int flags) > +{ > + char *hostname = NULL; > + unsigned short port = 0; > + char portstr[100]; > + virURIPtr uri = NULL; > + virNetSocketPtr sock; > + int sockfd = -1; > + int saved_errno = EINVAL; > + int ret = -1; > + Missing virCheckFlags(VIR_MIGRATE_LIVE, -1);