qemu_migration_params.c

/*
 * qemu_migration_params.c: QEMU migration parameters handling
 *
 * Copyright (C) 2006-2018 Red Hat, Inc.
 *
 * 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/>.
 *
 */

#include <config.h>

#include "virlog.h"
#include "virerror.h"
#include "viralloc.h"
#include "virstring.h"

#include "qemu_alias.h"
#include "qemu_hotplug.h"
#include "qemu_migration.h"
#include "qemu_migration_params.h"

#define VIR_FROM_THIS VIR_FROM_QEMU

VIR_LOG_INIT("qemu.qemu_migration_params");

#define QEMU_MIGRATION_TLS_ALIAS_BASE "libvirt_migrate"


void
qemuMigrationParamsClear(qemuMonitorMigrationParamsPtr migParams)
{
    if (!migParams)
        return;

    VIR_FREE(migParams->tlsCreds);
    VIR_FREE(migParams->tlsHostname);
}


void
qemuMigrationParamsFree(qemuMonitorMigrationParamsPtr *migParams)
{
    if (!*migParams)
        return;

    qemuMigrationParamsClear(*migParams);
    VIR_FREE(*migParams);
}


qemuMonitorMigrationParamsPtr
qemuMigrationParamsFromFlags(virTypedParameterPtr params,
                             int nparams,
                             unsigned long flags)
{
    qemuMonitorMigrationParamsPtr migParams;

    if (VIR_ALLOC(migParams) < 0)
        return NULL;

    if (!params)
        return migParams;

#define GET(PARAM, VAR) \
    do { \
        int rc; \
        if ((rc = virTypedParamsGetInt(params, nparams, \
                                       VIR_MIGRATE_PARAM_ ## PARAM, \
                                       &migParams->VAR)) < 0) \
            goto error; \
 \
        if (rc == 1) \
            migParams->VAR ## _set = true; \
    } while (0)

    GET(AUTO_CONVERGE_INITIAL, cpuThrottleInitial);
    GET(AUTO_CONVERGE_INCREMENT, cpuThrottleIncrement);

#undef GET

    if ((migParams->cpuThrottleInitial_set ||
         migParams->cpuThrottleIncrement_set) &&
        !(flags & VIR_MIGRATE_AUTO_CONVERGE)) {
        virReportError(VIR_ERR_INVALID_ARG, "%s",
                       _("Turn auto convergence on to tune it"));
        goto error;
    }

    return migParams;

 error:
    qemuMigrationParamsFree(&migParams);
    return NULL;
}


int
qemuMigrationParamsSet(virQEMUDriverPtr driver,
                       virDomainObjPtr vm,
                       int asyncJob,
                       qemuMonitorMigrationParamsPtr migParams)
{
    qemuDomainObjPrivatePtr priv = vm->privateData;
    int ret = -1;

    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
        return -1;

    if (qemuMonitorSetMigrationParams(priv->mon, migParams) < 0)
        goto cleanup;

    ret = 0;

 cleanup:
    if (qemuDomainObjExitMonitor(driver, vm) < 0)
        ret = -1;

    return ret;
}


/* qemuMigrationParamsCheckTLSCreds
 * @driver: pointer to qemu driver
 * @vm: domain object
 * @asyncJob: migration job to join
 *
 * Query the migration parameters looking for the 'tls-creds' parameter.
 * If found, then we can support setting or clearing the parameters and thus
 * can support TLS for migration.
 *
 * Returns 0 if we were able to successfully fetch the params and
 * additionally if the tls-creds parameter exists, saves it in the
 * private domain structure. Returns -1 on failure.
 */
static int
qemuMigrationParamsCheckTLSCreds(virQEMUDriverPtr driver,
                                 virDomainObjPtr vm,
                                 int asyncJob)
{
    int ret = -1;
    qemuDomainObjPrivatePtr priv = vm->privateData;
    qemuMonitorMigrationParams migParams = { 0 };

    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
        return -1;

    if (qemuMonitorGetMigrationParams(priv->mon, &migParams) < 0)
        goto cleanup;

    /* NB: Could steal NULL pointer too! Let caller decide what to do. */
    VIR_STEAL_PTR(priv->migTLSAlias, migParams.tlsCreds);

    ret = 0;

 cleanup:
    if (qemuDomainObjExitMonitor(driver, vm) < 0)
        ret = -1;

    qemuMigrationParamsClear(&migParams);

    return ret;
}


/* qemuMigrationParamsCheckSetupTLS
 * @driver: pointer to qemu driver
 * @vm: domain object
 * @cfg: configuration pointer
 * @asyncJob: migration job to join
 *
 * Check if TLS is possible and set up the environment. Assumes the caller
 * desires to use TLS (e.g. caller found VIR_MIGRATE_TLS flag).
 *
 * Ensure the qemu.conf has been properly configured to add an entry for
 * "migrate_tls_x509_cert_dir". Also check if the "tls-creds" parameter
 * was present from a query of migration parameters
 *
 * Returns 0 on success, -1 on error/failure
 */
int
qemuMigrationParamsCheckSetupTLS(virQEMUDriverPtr driver,
                                 virQEMUDriverConfigPtr cfg,
                                 virDomainObjPtr vm,
                                 int asyncJob)
{
    qemuDomainObjPrivatePtr priv = vm->privateData;

    if (!cfg->migrateTLSx509certdir) {
        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
                       _("host migration TLS directory not configured"));
        return -1;
    }

    if (qemuMigrationParamsCheckTLSCreds(driver, vm, asyncJob) < 0)
        return -1;

    if (!priv->migTLSAlias) {
        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
                       _("TLS migration is not supported with this "
                         "QEMU binary"));
        return -1;
    }

    /* If there's a secret, then grab/store it now using the connection */
    if (cfg->migrateTLSx509secretUUID &&
        !(priv->migSecinfo =
          qemuDomainSecretInfoTLSNew(priv, QEMU_MIGRATION_TLS_ALIAS_BASE,
                                     cfg->migrateTLSx509secretUUID)))
        return -1;

    return 0;
}


/* qemuMigrationParamsAddTLSObjects
 * @driver: pointer to qemu driver
 * @vm: domain object
 * @cfg: configuration pointer
 * @tlsListen: server or client
 * @asyncJob: Migration job to join
 * @tlsAlias: alias to be generated for TLS object
 * @secAlias: alias to be generated for a secinfo object
 * @migParams: migration parameters to set
 *
 * Create the TLS objects for the migration and set the migParams value
 *
 * Returns 0 on success, -1 on failure
 */
int
qemuMigrationParamsAddTLSObjects(virQEMUDriverPtr driver,
                                 virDomainObjPtr vm,
                                 virQEMUDriverConfigPtr cfg,
                                 bool tlsListen,
                                 int asyncJob,
                                 char **tlsAlias,
                                 char **secAlias,
                                 qemuMonitorMigrationParamsPtr migParams)
{
    qemuDomainObjPrivatePtr priv = vm->privateData;
    virJSONValuePtr tlsProps = NULL;
    virJSONValuePtr secProps = NULL;

    if (qemuDomainGetTLSObjects(priv->qemuCaps, priv->migSecinfo,
                                cfg->migrateTLSx509certdir, tlsListen,
                                cfg->migrateTLSx509verify,
                                QEMU_MIGRATION_TLS_ALIAS_BASE,
                                &tlsProps, tlsAlias, &secProps, secAlias) < 0)
        goto error;

    /* Ensure the domain doesn't already have the TLS objects defined...
     * This should prevent any issues just in case some cleanup wasn't
     * properly completed (both src and dst use the same alias) or
     * some other error path between now and perform . */
    qemuDomainDelTLSObjects(driver, vm, asyncJob, *secAlias, *tlsAlias);

    if (qemuDomainAddTLSObjects(driver, vm, asyncJob, *secAlias, &secProps,
                                *tlsAlias, &tlsProps) < 0)
        goto error;

    if (VIR_STRDUP(migParams->tlsCreds, *tlsAlias) < 0)
        goto error;

    return 0;

 error:
    virJSONValueFree(tlsProps);
    virJSONValueFree(secProps);
    return -1;
}


/* qemuMigrationParamsSetEmptyTLS
 * @driver: pointer to qemu driver
 * @vm: domain object
 * @asyncJob: migration job to join
 * @migParams: Pointer to a migration parameters block
 *
 * If we support setting the tls-creds, then set both tls-creds and
 * tls-hostname to the empty string ("") which indicates to not use
 * TLS on this migration.
 *
 * Returns 0 on success, -1 on failure
 */
int
qemuMigrationParamsSetEmptyTLS(virQEMUDriverPtr driver,
                               virDomainObjPtr vm,
                               int asyncJob,
                               qemuMonitorMigrationParamsPtr migParams)
{
   qemuDomainObjPrivatePtr priv = vm->privateData;

   if (qemuMigrationParamsCheckTLSCreds(driver, vm, asyncJob) < 0)
       return -1;

   if (!priv->migTLSAlias)
       return 0;

   if (VIR_STRDUP(migParams->tlsCreds, "") < 0 ||
       VIR_STRDUP(migParams->tlsHostname, "") < 0)
       return -1;

    return 0;
}


int
qemuMigrationParamsSetCompression(virQEMUDriverPtr driver,
                                  virDomainObjPtr vm,
                                  int asyncJob,
                                  qemuMigrationCompressionPtr compression,
                                  qemuMonitorMigrationParamsPtr migParams)
{
    int ret = -1;
    qemuDomainObjPrivatePtr priv = vm->privateData;

    if (qemuMigrationOptionSet(driver, vm,
                               QEMU_MONITOR_MIGRATION_CAPS_XBZRLE,
                               compression->methods &
                               (1ULL << QEMU_MIGRATION_COMPRESS_XBZRLE),
                               asyncJob) < 0)
        return -1;

    if (qemuMigrationOptionSet(driver, vm,
                               QEMU_MONITOR_MIGRATION_CAPS_COMPRESS,
                               compression->methods &
                               (1ULL << QEMU_MIGRATION_COMPRESS_MT),
                               asyncJob) < 0)
        return -1;

    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
        return -1;

    migParams->compressLevel_set = compression->level_set;
    migParams->compressLevel = compression->level;

    migParams->compressThreads_set = compression->threads_set;
    migParams->compressThreads = compression->threads;

    migParams->decompressThreads_set = compression->dthreads_set;
    migParams->decompressThreads = compression->dthreads;

    if (compression->xbzrle_cache_set &&
        qemuMonitorSetMigrationCacheSize(priv->mon,
                                         compression->xbzrle_cache) < 0)
        goto cleanup;

    ret = 0;

 cleanup:
    if (qemuDomainObjExitMonitor(driver, vm) < 0)
        ret = -1;

    return ret;
}


/* qemuMigrationParamsResetTLS
 * @driver: pointer to qemu driver
 * @vm: domain object
 * @asyncJob: migration job to join
 *
 * Deconstruct all the setup possibly done for TLS - delete the TLS and
 * security objects, free the secinfo, and reset the migration params to "".
 *
 * Returns 0 on success, -1 on failure
 */
static int
qemuMigrationParamsResetTLS(virQEMUDriverPtr driver,
                            virDomainObjPtr vm,
                            int asyncJob)
{
    qemuDomainObjPrivatePtr priv = vm->privateData;
    char *tlsAlias = NULL;
    char *secAlias = NULL;
    qemuMonitorMigrationParams migParams = { 0 };
    int ret = -1;

    if (qemuMigrationParamsCheckTLSCreds(driver, vm, asyncJob) < 0)
        return -1;

    /* If the tls-creds doesn't exist or if they're set to "" then there's
     * nothing to do since we never set anything up */
    if (!priv->migTLSAlias || !*priv->migTLSAlias)
        return 0;

    /* NB: If either or both fail to allocate memory we can still proceed
     *     since the next time we migrate another deletion attempt will be
     *     made after successfully generating the aliases. */
    tlsAlias = qemuAliasTLSObjFromSrcAlias(QEMU_MIGRATION_TLS_ALIAS_BASE);
    secAlias = qemuDomainGetSecretAESAlias(QEMU_MIGRATION_TLS_ALIAS_BASE, false);

    qemuDomainDelTLSObjects(driver, vm, asyncJob, secAlias, tlsAlias);
    qemuDomainSecretInfoFree(&priv->migSecinfo);

    if (VIR_STRDUP(migParams.tlsCreds, "") < 0 ||
        VIR_STRDUP(migParams.tlsHostname, "") < 0 ||
        qemuMigrationParamsSet(driver, vm, asyncJob, &migParams) < 0)
        goto cleanup;

    ret = 0;

 cleanup:
    VIR_FREE(tlsAlias);
    VIR_FREE(secAlias);
    qemuMigrationParamsClear(&migParams);

    return ret;
}


/*
 * qemuMigrationParamsReset:
 *
 * Reset all migration parameters so that the next job which internally uses
 * migration (save, managedsave, snapshots, dump) will not try to use them.
 */
void
qemuMigrationParamsReset(virQEMUDriverPtr driver,
                         virDomainObjPtr vm,
                         int asyncJob)
{
    qemuMonitorMigrationCaps cap;
    virErrorPtr err = virSaveLastError();

    if (!virDomainObjIsActive(vm))
        goto cleanup;

    if (qemuMigrationParamsResetTLS(driver, vm, asyncJob) < 0)
        goto cleanup;

    for (cap = 0; cap < QEMU_MONITOR_MIGRATION_CAPS_LAST; cap++) {
        if (qemuMigrationCapsGet(vm, cap) &&
            qemuMigrationOptionSet(driver, vm, cap, false, asyncJob) < 0)
            goto cleanup;
    }

 cleanup:
    if (err) {
        virSetError(err);
        virFreeError(err);
    }
}