Re: [libvirt] [RFC PATCH] libxl: add tunnelled migration support

Tunnelled migration doesn't require any extra network connections beside the libvirt daemon. It's capable of strong encryption and is the default option in openstack-nova. This patch add the tunnelled migration(Tunnel3params) support to libxl. The data flow in the src side is: * libxlDoMigrateSend() -> pipe * libxlTunnel3MigrationFunc() poll pipe out and then write to dest stream. While in the dest side: Stream -> pipe -> 'recvfd of libxlDomainStartRestore' The usage is the same as p2p migration, execpt adding one more '--tunnelled' to

the libvirt p2p migration command. Signed-off-by: Bob Liu <bob.liu(a)oracle.com&gt;

--- src/libxl/libxl_driver.c | 58 ++++++++++- src/libxl/libxl_migration.c | 241 +++++++++++++++++++++++++++++++++++++++++--- src/libxl/libxl_migration.h | 9 ++ 3 files changed, 292 insertions(+), 16 deletions(-) diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c index b66cb1f..a01bbff 100644 --- a/src/libxl/libxl_driver.c +++ b/src/libxl/libxl_driver.c @@ -5918,6 +5918,61 @@ libxlDomainMigrateBegin3Params(virDomainPtr domain, } static int +libxlDomainMigratePrepareTunnel3Params(virConnectPtr dconn, + virStreamPtr st, + virTypedParameterPtr params, + int nparams, + const char *cookiein, + int cookieinlen, + char **cookieout ATTRIBUTE_UNUSED, + int *cookieoutlen ATTRIBUTE_UNUSED, + unsigned int flags) +{ + libxlDriverPrivatePtr driver = dconn->privateData; + virDomainDefPtr def = NULL; + const char *dom_xml = NULL; + const char *dname = NULL; + const char *uri_in = NULL; + +#ifdef LIBXL_HAVE_NO_SUSPEND_RESUME + virReportUnsupportedError(); + return -1; +#endif + + virCheckFlags(LIBXL_MIGRATION_FLAGS, -1); + if (virTypedParamsValidate(params, nparams, LIBXL_MIGRATION_PARAMETERS) < 0) + goto error; + + if (virTypedParamsGetString(params, nparams, + VIR_MIGRATE_PARAM_DEST_XML, + &dom_xml) < 0 || + virTypedParamsGetString(params, nparams, + VIR_MIGRATE_PARAM_DEST_NAME, + &dname) < 0 || + virTypedParamsGetString(params, nparams, + VIR_MIGRATE_PARAM_URI, + &uri_in) < 0) + + goto error; + + if (!(def = libxlDomainMigrationPrepareDef(driver, dom_xml, dname))) + goto error; + + if (virDomainMigratePrepareTunnel3ParamsEnsureACL(dconn, def) < 0) + goto error; + + if (libxlDomainMigrationPrepareTunnel3(dconn, st, &def, cookiein, + cookieinlen, flags) < 0) + goto error; + + return 0; + + error: + virDomainDefFree(def); + return -1; +} + +static int libxlDomainMigratePrepare3Params(virConnectPtr dconn, virTypedParameterPtr params, int nparams, @@ -6017,7 +6072,7 @@ libxlDomainMigratePerform3Params(virDomainPtr dom, if (virDomainMigratePerform3ParamsEnsureACL(dom->conn, vm->def) < 0) goto cleanup; - if (flags & VIR_MIGRATE_PEER2PEER) { + if ((flags & (VIR_MIGRATE_TUNNELLED | VIR_MIGRATE_PEER2PEER))) { if (libxlDomainMigrationPerformP2P(driver, vm, dom->conn, dom_xml, dconnuri, uri, dname, flags) < 0) goto cleanup; @@ -6501,6 +6556,7 @@ static virHypervisorDriver libxlHypervisorDriver = { .nodeDeviceReset = libxlNodeDeviceReset, /* 1.2.3 */ .domainMigrateBegin3Params = libxlDomainMigrateBegin3Params, /* 1.2.6 */ .domainMigratePrepare3Params = libxlDomainMigratePrepare3Params, /* 1.2.6 */ + .domainMigratePrepareTunnel3Params = libxlDomainMigratePrepareTunnel3Params, /* 2.3.1 */

.domainMigratePerform3Params = libxlDomainMigratePerform3Params, /* 1.2.6 */ .domainMigrateFinish3Params = libxlDomainMigrateFinish3Params, /* 1.2.6 */ .domainMigrateConfirm3Params = libxlDomainMigrateConfirm3Params, /* 1.2.6 */ diff --git a/src/libxl/libxl_migration.c b/src/libxl/libxl_migration.c index 534abb8..88c9bb8 100644 --- a/src/libxl/libxl_migration.c +++ b/src/libxl/libxl_migration.c @@ -44,6 +44,7 @@ #include "libxl_migration.h" #include "locking/domain_lock.h" #include "virtypedparam.h" +#include "fdstream.h" #define VIR_FROM_THIS VIR_FROM_LIBXL @@ -484,6 +485,90 @@ libxlDomainMigrationPrepareDef(libxlDriverPrivatePtr driver, } int +libxlDomainMigrationPrepareTunnel3(virConnectPtr dconn, + virStreamPtr st, + virDomainDefPtr *def, + const char *cookiein, + int cookieinlen, + unsigned int flags) +{ + libxlMigrationCookiePtr mig = NULL; + libxlDriverPrivatePtr driver = dconn->privateData; + virDomainObjPtr vm = NULL; + libxlMigrationDstArgs *args = NULL; + virThread thread; + int dataFD[2] = { -1, -1 }; + int ret = 0;

+ + if (libxlMigrationEatCookie(cookiein, cookieinlen, &mig) < 0) + goto error; + + if (mig->xenMigStreamVer > LIBXL_SAVE_VERSION) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("Xen migration stream version '%d' is not supported on this host"), + mig->xenMigStreamVer); + goto error; + } + + if (!(vm = virDomainObjListAdd(driver->domains, *def, + driver->xmlopt, + VIR_DOMAIN_OBJ_LIST_ADD_LIVE | + VIR_DOMAIN_OBJ_LIST_ADD_CHECK_LIVE, + NULL))) + goto error; + + /* + * The data flow of tunnel3 migration in the dest side: + * stream -> pipe -> recvfd of libxlDomainStartRestore + */ + if (pipe(dataFD) < 0) + goto error; + + /* Stream data will be written to pipeIn */ + if (virFDStreamOpen(st, dataFD[1]) < 0) + goto error;

+ + if (libxlMigrationDstArgsInitialize() < 0) + goto error; + + if (!(args = virObjectNew(libxlMigrationDstArgsClass))) + goto error; + + args->conn = dconn; + args->vm = vm; + args->flags = flags; + args->migcookie = mig; + /* Receive from pipeOut */ + args->recvfd = dataFD[0]; + args->nsocks = 0; + if (virThreadCreate(&thread, false, libxlDoMigrateReceive, args) < 0) { + virReportError(VIR_ERR_OPERATION_FAILED, "%s", + _("Failed to create thread for receiving migration data")); + goto error; + } + + goto done;

+ + error: + VIR_FORCE_CLOSE(dataFD[1]); + VIR_FORCE_CLOSE(dataFD[0]); + virObjectUnref(args); + /* Remove virDomainObj from domain list */ + if (vm) { + virDomainObjListRemove(driver->domains, vm); + vm = NULL; + } + ret = -1;

+ + done: + /* Nobody will close dataFD[1]? */

+ if (vm) + virObjectUnlock(vm); + + return ret; +} + +int libxlDomainMigrationPrepare(virConnectPtr dconn, virDomainDefPtr *def, const char *uri_in, @@ -710,9 +795,90 @@ libxlDomainMigrationPrepare(virConnectPtr dconn, return ret; } -/* This function is a simplification of virDomainMigrateVersion3Full - * excluding tunnel support and restricting it to migration v3 - * with params since it was the first to be introduced in libxl. +typedef struct _libxlTunnelMigrationThread libxlTunnelMigrationThread; +struct _libxlTunnelMigrationThread { + virThread thread; + virStreamPtr st; + int srcFD; +}; +#define TUNNEL_SEND_BUF_SIZE 65536 + +/* + * The data flow of tunnel3 migration in the src side: + * libxlDoMigrateSend() -> pipe + * libxlTunnel3MigrationFunc() polls pipe out and then write to dest stream. + */ +static void libxlTunnel3MigrationFunc(void *arg) +{ + libxlTunnelMigrationThread *data = (libxlTunnelMigrationThread *)arg; + char *buffer = NULL; + struct pollfd fds[1]; + int timeout = -1; + + if (VIR_ALLOC_N(buffer, TUNNEL_SEND_BUF_SIZE) < 0) { + virReportError(errno, "%s", _("poll failed in migration tunnel")); + return; + } + + fds[0].fd = data->srcFD; + for (;;) { + int ret; + + fds[0].events = POLLIN; + fds[0].revents = 0; + ret = poll(fds, ARRAY_CARDINALITY(fds), timeout); + if (ret < 0) { + if (errno == EAGAIN || errno == EINTR) + continue; + virReportError(errno, "%s", + _("poll failed in libxlTunnel3MigrationFunc")); + goto abrt; + } + + if (ret == 0) { + VIR_DEBUG("poll got timeout"); + break; + } + + if (fds[0].revents & (POLLIN | POLLERR | POLLHUP)) { + int nbytes; + + nbytes = read(data->srcFD, buffer, TUNNEL_SEND_BUF_SIZE); + if (nbytes > 0) { + /* Write to dest stream */ + if (virStreamSend(data->st, buffer, nbytes) < 0) { + virReportError(errno, "%s", + _("tunnelled migration failed to send to virStream")); + goto abrt; + } + } else if (nbytes < 0) { + virReportError(errno, "%s", + _("tunnelled migration failed to read from xen side")); + goto abrt; + } else { + /* EOF; transferred all data */ + break; + } + } + } + + if (virStreamFinish(data->st) < 0) + virReportError(errno, "%s", + _("tunnelled migration failed to finish stream")); + + cleanup: + VIR_FREE(buffer); + + return; + + abrt:

+ virStreamAbort(data->st); + goto cleanup; +} + +/* This function is a simplification of virDomainMigrateVersion3Full and + * restricting it to migration v3 with params since it was the first to be + * introduced in libxl. */ static int libxlDoMigrateP2P(libxlDriverPrivatePtr driver, @@ -737,6 +903,10 @@ libxlDoMigrateP2P(libxlDriverPrivatePtr driver, bool cancelled = true; virErrorPtr orig_err = NULL; int ret = -1; + /* For tunnel migration */ + virStreamPtr st = NULL; + libxlTunnelMigrationThread *libxlTunnelMigationThreadPtr = NULL;

+ int dataFD[2] = { -1, -1 }; dom_xml = libxlDomainMigrationBegin(sconn, vm, xmlin, &cookieout, &cookieoutlen); @@ -764,29 +934,62 @@ libxlDoMigrateP2P(libxlDriverPrivatePtr driver, VIR_DEBUG("Prepare3"); virObjectUnlock(vm); - ret = dconn->driver->domainMigratePrepare3Params - (dconn, params, nparams, cookieout, cookieoutlen, NULL, NULL, &uri_out, destflags); + if (flags & VIR_MIGRATE_TUNNELLED) { + if (!(st = virStreamNew(dconn, 0))) + goto cleanup; + ret = dconn->driver->domainMigratePrepareTunnel3Params + (dconn, st, params, nparams, cookieout, cookieoutlen, NULL, NULL, destflags); + } else { + ret = dconn->driver->domainMigratePrepare3Params + (dconn, params, nparams, cookieout, cookieoutlen, NULL, NULL, &uri_out, destflags); + } virObjectLock(vm); if (ret == -1) goto cleanup; - if (uri_out) { - if (virTypedParamsReplaceString(&params, &nparams, - VIR_MIGRATE_PARAM_URI, uri_out) < 0) { - orig_err = virSaveLastError(); + if (!(flags & VIR_MIGRATE_TUNNELLED)) { + if (uri_out) { + if (virTypedParamsReplaceString(&params, &nparams, + VIR_MIGRATE_PARAM_URI, uri_out) < 0) { + orig_err = virSaveLastError(); + goto finish; + } + } else { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("domainMigratePrepare3 did not set uri")); goto finish; } - } else { - virReportError(VIR_ERR_INTERNAL_ERROR, "%s", - _("domainMigratePrepare3 did not set uri")); - goto finish; } VIR_DEBUG("Perform3 uri=%s", NULLSTR(uri_out)); - ret = libxlDomainMigrationPerform(driver, vm, NULL, NULL, - uri_out, NULL, flags); + if (flags & VIR_MIGRATE_TUNNELLED) { + if (VIR_ALLOC(libxlTunnelMigationThreadPtr) < 0) + goto cleanup; + if (pipe(dataFD) < 0) { + virReportError(errno, "%s", _("Unable to make pipes")); + goto cleanup; + } + /* Read from pipe */ + libxlTunnelMigationThreadPtr->srcFD = dataFD[0]; + /* Write to dest stream */ + libxlTunnelMigationThreadPtr->st = st; + if (virThreadCreate(&libxlTunnelMigationThreadPtr->thread, true, + libxlTunnel3MigrationFunc, + libxlTunnelMigationThreadPtr) < 0) { + virReportError(errno, "%s", + _("Unable to create tunnel migration thread")); + goto cleanup; + }

+ virObjectUnlock(vm); + /* Send data to pipe */ + ret = libxlDoMigrateSend(driver, vm, flags, dataFD[1]); + virObjectLock(vm); + } else { + ret = libxlDomainMigrationPerform(driver, vm, NULL, NULL, + uri_out, NULL, flags); + } if (ret < 0) orig_err = virSaveLastError(); @@ -824,6 +1027,14 @@ libxlDoMigrateP2P(libxlDriverPrivatePtr driver, vm->def->name); cleanup: + if (libxlTunnelMigationThreadPtr) { + virThreadCancel(&libxlTunnelMigationThreadPtr->thread); + VIR_FREE(libxlTunnelMigationThreadPtr); + } + VIR_FORCE_CLOSE(dataFD[0]); + VIR_FORCE_CLOSE(dataFD[1]);