Re: [libvirt] [PATCH v2 02/11] Introduce NBD migration cookie

This migration cookie is meant for two purposes. The first is to be sent in begin phase from source to destination to let it know we support new implementation of VIR_MIGRATE_NON_SHARED_{DISK,INC} so destination can start NBD server. Then, the second purpose is, destination can let us know, on which port is NBD server running. --- src/qemu/qemu_migration.c | 117 ++++++++++++++++++++++++++++++++++++++++---- 1 files changed, 106 insertions(+), 11 deletions(-) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 86060dc..8c1e873 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -72,6 +72,7 @@ enum qemuMigrationCookieFlags { QEMU_MIGRATION_COOKIE_FLAG_LOCKSTATE, QEMU_MIGRATION_COOKIE_FLAG_PERSISTENT, QEMU_MIGRATION_COOKIE_FLAG_NETWORK, + QEMU_MIGRATION_COOKIE_FLAG_NBD, QEMU_MIGRATION_COOKIE_FLAG_LAST }; @@ -79,13 +80,18 @@ enum qemuMigrationCookieFlags { VIR_ENUM_DECL(qemuMigrationCookieFlag); VIR_ENUM_IMPL(qemuMigrationCookieFlag, QEMU_MIGRATION_COOKIE_FLAG_LAST, - "graphics", "lockstate", "persistent", "network"); + "graphics", + "lockstate", + "persistent", + "network", + "nbd"); enum qemuMigrationCookieFeatures { QEMU_MIGRATION_COOKIE_GRAPHICS = (1 << QEMU_MIGRATION_COOKIE_FLAG_GRAPHICS), QEMU_MIGRATION_COOKIE_LOCKSTATE = (1 << QEMU_MIGRATION_COOKIE_FLAG_LOCKSTATE), QEMU_MIGRATION_COOKIE_PERSISTENT = (1 << QEMU_MIGRATION_COOKIE_FLAG_PERSISTENT), QEMU_MIGRATION_COOKIE_NETWORK = (1 << QEMU_MIGRATION_COOKIE_FLAG_NETWORK), + QEMU_MIGRATION_COOKIE_NBD = (1 << QEMU_MIGRATION_COOKIE_FLAG_NBD), }; typedef struct _qemuMigrationCookieGraphics qemuMigrationCookieGraphics; @@ -119,6 +125,17 @@ struct _qemuMigrationCookieNetwork { qemuMigrationCookieNetDataPtr net; }; +typedef struct _qemuMigrationCookieNBD qemuMigrationCookieNBD; +typedef qemuMigrationCookieNBD *qemuMigrationCookieNBDPtr; +struct _qemuMigrationCookieNBD { + int port; /* on which port does NBD server listen for incoming data. + Zero value has special meaning - it is there just to let + destination know we (the source) do support NBD. + Negative one is meant to be sent when translating from + perform to finish phase to let destination know it's + safe to stop NBD server.*/ +}; + typedef struct _qemuMigrationCookie qemuMigrationCookie; typedef qemuMigrationCookie *qemuMigrationCookiePtr; struct _qemuMigrationCookie { @@ -147,6 +164,9 @@ struct _qemuMigrationCookie { /* If (flags & QEMU_MIGRATION_COOKIE_NETWORK) */ qemuMigrationCookieNetworkPtr network; + + /* If (flags & QEMU_MIGRATION_COOKIE_NBD) */ + qemuMigrationCookieNBDPtr nbd; }; static void qemuMigrationCookieGraphicsFree(qemuMigrationCookieGraphicsPtr grap) @@ -192,6 +212,7 @@ static void qemuMigrationCookieFree(qemuMigrationCookiePtr mig) VIR_FREE(mig->name); VIR_FREE(mig->lockState); VIR_FREE(mig->lockDriver); + VIR_FREE(mig->nbd); VIR_FREE(mig); } @@ -492,6 +513,24 @@ qemuMigrationCookieAddNetwork(qemuMigrationCookiePtr mig, } +static int +qemuMigrationCookieAddNBD(qemuMigrationCookiePtr mig, + int nbdPort) +{ + /* It is not a bug if there already is a NBD data */ + if (!mig->nbd && + VIR_ALLOC(mig->nbd) < 0) { + virReportOOMError(); + return -1; + } + + mig->nbd->port = nbdPort; + mig->flags |= QEMU_MIGRATION_COOKIE_NBD; + + return 0; +} + + static void qemuMigrationCookieGraphicsXMLFormat(virBufferPtr buf, qemuMigrationCookieGraphicsPtr grap) { @@ -594,6 +633,13 @@ qemuMigrationCookieXMLFormat(virQEMUDriverPtr driver, if ((mig->flags & QEMU_MIGRATION_COOKIE_NETWORK) && mig->network) qemuMigrationCookieNetworkXMLFormat(buf, mig->network); + if ((mig->flags & QEMU_MIGRATION_COOKIE_NBD) && mig->nbd) { + virBufferAddLit(buf, " <nbd"); + if (mig->nbd->port) + virBufferAsprintf(buf, " port='%d'", mig->nbd->port); + virBufferAddLit(buf, "/>\n"); + } + virBufferAddLit(buf, "</qemu-migration>\n"); return 0; } @@ -821,6 +867,12 @@ qemuMigrationCookieXMLParse(qemuMigrationCookiePtr mig, goto error; } + /* nbd is optional */ + if (val == QEMU_MIGRATION_COOKIE_FLAG_NBD) { + VIR_FREE(str); + continue; + } + if ((flags & (1 << val)) == 0) { virReportError(VIR_ERR_INTERNAL_ERROR, _("Unsupported migration cookie feature %s"), @@ -873,6 +925,25 @@ qemuMigrationCookieXMLParse(qemuMigrationCookiePtr mig, (!(mig->network = qemuMigrationCookieNetworkXMLParse(ctxt)))) goto error; + if (flags & QEMU_MIGRATION_COOKIE_NBD && + virXPathBoolean("count(./nbd) > 0", ctxt)) { + char *port; + + if (VIR_ALLOC(mig->nbd) < 0) { + virReportOOMError(); + goto error; + } + + port = virXPathString("string(./nbd/@port)", ctxt); + if (port && + virStrToLong_i(port, NULL, 10, &mig->nbd->port) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Malformed nbd port '%s'"), + port); + goto error; + } + } + return 0; error: @@ -911,6 +982,7 @@ static int qemuMigrationBakeCookie(qemuMigrationCookiePtr mig, virQEMUDriverPtr driver, virDomainObjPtr dom, + int nbdPort, char **cookieout, int *cookieoutlen, unsigned int flags) @@ -937,6 +1009,10 @@ qemuMigrationBakeCookie(qemuMigrationCookiePtr mig, return -1; } + if (flags & QEMU_MIGRATION_COOKIE_NBD && + qemuMigrationCookieAddNBD(mig, nbdPort) < 0) + return -1; + if (!(*cookieout = qemuMigrationCookieXMLFormatStr(driver, mig))) return -1; @@ -1415,6 +1491,7 @@ char *qemuMigrationBegin(virQEMUDriverPtr driver, qemuMigrationCookiePtr mig = NULL; virDomainDefPtr def = NULL; qemuDomainObjPrivatePtr priv = vm->privateData; + unsigned int cookie_flags = QEMU_MIGRATION_COOKIE_LOCKSTATE; VIR_DEBUG("driver=%p, vm=%p, xmlin=%s, dname=%s," " cookieout=%p, cookieoutlen=%p, flags=%lx", @@ -1434,12 +1511,20 @@ char *qemuMigrationBegin(virQEMUDriverPtr driver, if (!(flags & VIR_MIGRATE_UNSAFE) && !qemuMigrationIsSafe(vm->def)) goto cleanup; + if (qemuCapsGet(priv->caps, QEMU_CAPS_NBD_SERVER)) { + /* TODO support NBD for TUNNELLED migration */ + if (flags & VIR_MIGRATE_TUNNELLED) + VIR_DEBUG("NBD in tunnelled migration is currently not supported"); + else + cookie_flags |= QEMU_MIGRATION_COOKIE_NBD; + } +

if (!(mig = qemuMigrationEatCookie(driver, vm, NULL, 0, 0))) goto cleanup; - if (qemuMigrationBakeCookie(mig, driver, vm, + if (qemuMigrationBakeCookie(mig, driver, vm, 0, cookieout, cookieoutlen, - QEMU_MIGRATION_COOKIE_LOCKSTATE) < 0) + cookie_flags) < 0) goto cleanup; if (xmlin) { @@ -1512,6 +1597,8 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver, bool tunnel = !!st; char *origname = NULL; char *xmlout = NULL; + int nbdPort = 0; + unsigned int cookie_flags = QEMU_MIGRATION_COOKIE_GRAPHICS; if (virTimeMillisNow(&now) < 0) return -1; @@ -1589,7 +1676,8 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver, origname = NULL; if (!(mig = qemuMigrationEatCookie(driver, vm, cookiein, cookieinlen, - QEMU_MIGRATION_COOKIE_LOCKSTATE))) + QEMU_MIGRATION_COOKIE_LOCKSTATE | + QEMU_MIGRATION_COOKIE_NBD))) goto cleanup; if (qemuMigrationJobStart(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0) @@ -1640,8 +1728,12 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver, VIR_DEBUG("Received no lockstate"); } - if (qemuMigrationBakeCookie(mig, driver, vm, cookieout, cookieoutlen, - QEMU_MIGRATION_COOKIE_GRAPHICS) < 0) { + /* dummy place holder for real work */ + nbdPort = 0; + cookie_flags |= QEMU_MIGRATION_COOKIE_NBD; + + if (qemuMigrationBakeCookie(mig, driver, vm, nbdPort, + cookieout, cookieoutlen, cookie_flags) < 0) { /* We could tear down the whole guest here, but * cookie data is (so far) non-critical, so that * seems a little harsh. We'll just warn for now. @@ -2150,7 +2242,8 @@ qemuMigrationRun(virQEMUDriverPtr driver, } if (!(mig = qemuMigrationEatCookie(driver, vm, cookiein, cookieinlen, - QEMU_MIGRATION_COOKIE_GRAPHICS))) + QEMU_MIGRATION_COOKIE_GRAPHICS | + QEMU_MIGRATION_COOKIE_NBD))) goto cleanup; if (qemuDomainMigrateGraphicsRelocate(driver, vm, mig) < 0) @@ -2296,9 +2389,10 @@ cleanup: } if (ret == 0 && - qemuMigrationBakeCookie(mig, driver, vm, cookieout, cookieoutlen, + qemuMigrationBakeCookie(mig, driver, vm, -1, cookieout, cookieoutlen, QEMU_MIGRATION_COOKIE_PERSISTENT | - QEMU_MIGRATION_COOKIE_NETWORK) < 0) { + QEMU_MIGRATION_COOKIE_NETWORK | + QEMU_MIGRATION_COOKIE_NBD) < 0) { VIR_WARN("Unable to encode migration cookie"); } @@ -3233,7 +3327,7 @@ qemuMigrationFinish(virQEMUDriverPtr driver, qemuDomainCleanupRemove(vm, qemuMigrationPrepareCleanup); - cookie_flags = QEMU_MIGRATION_COOKIE_NETWORK; + cookie_flags = QEMU_MIGRATION_COOKIE_NETWORK | QEMU_MIGRATION_COOKIE_NBD; if (flags & VIR_MIGRATE_PERSIST_DEST) cookie_flags |= QEMU_MIGRATION_COOKIE_PERSISTENT; @@ -3377,7 +3471,8 @@ qemuMigrationFinish(virQEMUDriverPtr driver, VIR_DOMAIN_EVENT_STOPPED_FAILED); } - if (qemuMigrationBakeCookie(mig, driver, vm, cookieout, cookieoutlen, 0) < 0) + if (qemuMigrationBakeCookie(mig, driver, vm, 0, + cookieout, cookieoutlen, 0) < 0) VIR_WARN("Unable to encode migration cookie"); endjob: