qemu: allow blkstat/blkinfo calls during migration

Originally most of libvirt domain-specific calls were blocking
during a migration.
A new mechanism to allow specific calls (blkstat/blkinfo) to be
executed in such condition has been implemented.
In the long term it'd be desirable to get a more general
solution to mark further APIs as migration safe, without needing
special case code.

 * src/qemu/qemu_migration.c: add some additional job signal
   flags for doing blkstat/blkinfo during a migration
 * src/qemu/qemu_domain.c: add a condition variable that can be
   used to efficiently wait for the migration code to clear the
   signal flag
 * src/qemu/qemu_driver.c: execute blkstat/blkinfo using the
   job signal flags during migration
This commit is contained in:
Federico Simoncelli 2011-05-13 06:11:47 -04:00 committed by Eric Blake
parent fffea7fed7
commit 18c2a59206
6 changed files with 154 additions and 50 deletions

View File

@ -20,3 +20,4 @@
<cfergeau@redhat.com> <teuf@gnome.org>
<wency@cn.fujitsu.com> <wency cn fujitsu com>
<cardoe@cardoe.com> <cardoe@gentoo.org>
<fsimonce@redhat.com> <federico.simoncelli@gmail.com>

View File

@ -83,7 +83,7 @@ Patches have also been contributed by:
Abel Míguez Rodríguez<amiguezr@pdi.ucm.es>
Doug Goldstein <cardoe@cardoe.com>
Javier Fontan <jfontan@gmail.com>
Federico Simoncelli <federico.simoncelli@gmail.com>
Federico Simoncelli <fsimonce@redhat.com>
Amy Griffis <amy.griffis@hp.com>
Henrik Persson E <henrik.e.persson@ericsson.com>
Satoru SATOH <satoru.satoh@gmail.com>

View File

@ -89,7 +89,19 @@ static void *qemuDomainObjPrivateAlloc(void)
if (VIR_ALLOC(priv) < 0)
return NULL;
if (virCondInit(&priv->jobCond) < 0)
goto initfail;
if (virCondInit(&priv->signalCond) < 0) {
ignore_value(virCondDestroy(&priv->jobCond));
goto initfail;
}
return priv;
initfail:
VIR_FREE(priv);
return NULL;
}
static void qemuDomainObjPrivateFree(void *data)
@ -101,6 +113,8 @@ static void qemuDomainObjPrivateFree(void *data)
qemuDomainPCIAddressSetFree(priv->pciaddrs);
virDomainChrSourceDefFree(priv->monConfig);
VIR_FREE(priv->vcpupids);
ignore_value(virCondDestroy(&priv->jobCond));
ignore_value(virCondDestroy(&priv->signalCond));
/* This should never be non-NULL if we get here, but just in case... */
if (priv->mon) {

View File

@ -47,11 +47,19 @@ enum qemuDomainJobSignals {
QEMU_JOB_SIGNAL_SUSPEND = 1 << 1, /* Request VM suspend to finish live migration offline */
QEMU_JOB_SIGNAL_MIGRATE_DOWNTIME = 1 << 2, /* Request migration downtime change */
QEMU_JOB_SIGNAL_MIGRATE_SPEED = 1 << 3, /* Request migration speed change */
QEMU_JOB_SIGNAL_BLKSTAT = 1 << 4, /* Request blkstat during migration */
QEMU_JOB_SIGNAL_BLKINFO = 1 << 5, /* Request blkinfo during migration */
};
struct qemuDomainJobSignalsData {
unsigned long long migrateDowntime; /* Data for QEMU_JOB_SIGNAL_MIGRATE_DOWNTIME */
unsigned long migrateBandwidth; /* Data for QEMU_JOB_SIGNAL_MIGRATE_SPEED */
char *statDevName; /* Device name used by blkstat calls */
virDomainBlockStatsPtr blockStat; /* Block statistics for QEMU_JOB_SIGNAL_BLKSTAT */
int *statRetCode; /* Return code for the blkstat calls */
char *infoDevName; /* Device name used by blkinfo calls */
virDomainBlockInfoPtr blockInfo; /* Block information for QEMU_JOB_SIGNAL_BLKINFO */
int *infoRetCode; /* Return code for the blkinfo calls */
};
typedef struct _qemuDomainPCIAddressSet qemuDomainPCIAddressSet;
@ -61,6 +69,7 @@ typedef struct _qemuDomainObjPrivate qemuDomainObjPrivate;
typedef qemuDomainObjPrivate *qemuDomainObjPrivatePtr;
struct _qemuDomainObjPrivate {
virCond jobCond; /* Use in conjunction with main virDomainObjPtr lock */
virCond signalCond; /* Use to coordinate the safe queries during migration */
enum qemuDomainJob jobActive; /* Currently running job */
unsigned int jobSignals; /* Signals for running job */
struct qemuDomainJobSignalsData jobSignalsData; /* Signal specific data */

View File

@ -5278,15 +5278,6 @@ qemudDomainBlockStats (virDomainPtr dom,
goto cleanup;
}
if (qemuDomainObjBeginJob(vm) < 0)
goto cleanup;
if (!virDomainObjIsActive(vm)) {
qemuReportError(VIR_ERR_OPERATION_INVALID,
"%s", _("domain is not running"));
goto endjob;
}
for (i = 0 ; i < vm->def->ndisks ; i++) {
if (STREQ(path, vm->def->disks[i]->dst)) {
disk = vm->def->disks[i];
@ -5297,16 +5288,42 @@ qemudDomainBlockStats (virDomainPtr dom,
if (!disk) {
qemuReportError(VIR_ERR_INVALID_ARG,
_("invalid path: %s"), path);
goto endjob;
goto cleanup;
}
if (!disk->info.alias) {
qemuReportError(VIR_ERR_INTERNAL_ERROR,
_("missing disk device alias name for %s"), disk->dst);
goto endjob;
goto cleanup;
}
priv = vm->privateData;
if ((priv->jobActive == QEMU_JOB_MIGRATION_OUT)
|| (priv->jobActive == QEMU_JOB_SAVE)) {
virDomainObjRef(vm);
while (priv->jobSignals & QEMU_JOB_SIGNAL_BLKSTAT)
ignore_value(virCondWait(&priv->signalCond, &vm->lock));
priv->jobSignalsData.statDevName = disk->info.alias;
priv->jobSignalsData.blockStat = stats;
priv->jobSignalsData.statRetCode = &ret;
priv->jobSignals |= QEMU_JOB_SIGNAL_BLKSTAT;
while (priv->jobSignals & QEMU_JOB_SIGNAL_BLKSTAT)
ignore_value(virCondWait(&priv->signalCond, &vm->lock));
if (virDomainObjUnref(vm) == 0)
vm = NULL;
} else {
if (qemuDomainObjBeginJob(vm) < 0)
goto cleanup;
if (!virDomainObjIsActive(vm)) {
qemuReportError(VIR_ERR_OPERATION_INVALID,
"%s", _("domain is not running"));
goto endjob;
}
qemuDomainObjEnterMonitor(vm);
ret = qemuMonitorGetBlockStatsInfo(priv->mon,
disk->info.alias,
@ -5320,6 +5337,7 @@ qemudDomainBlockStats (virDomainPtr dom,
endjob:
if (qemuDomainObjEndJob(vm) == 0)
vm = NULL;
}
cleanup:
if (vm)
@ -5725,20 +5743,43 @@ static int qemuDomainGetBlockInfo(virDomainPtr dom,
format != VIR_STORAGE_FILE_RAW &&
S_ISBLK(sb.st_mode)) {
qemuDomainObjPrivatePtr priv = vm->privateData;
if ((priv->jobActive == QEMU_JOB_MIGRATION_OUT)
|| (priv->jobActive == QEMU_JOB_SAVE)) {
virDomainObjRef(vm);
while (priv->jobSignals & QEMU_JOB_SIGNAL_BLKINFO)
ignore_value(virCondWait(&priv->signalCond, &vm->lock));
priv->jobSignalsData.infoDevName = disk->info.alias;
priv->jobSignalsData.blockInfo = info;
priv->jobSignalsData.infoRetCode = &ret;
priv->jobSignals |= QEMU_JOB_SIGNAL_BLKINFO;
while (priv->jobSignals & QEMU_JOB_SIGNAL_BLKINFO)
ignore_value(virCondWait(&priv->signalCond, &vm->lock));
if (virDomainObjUnref(vm) == 0)
vm = NULL;
} else {
if (qemuDomainObjBeginJob(vm) < 0)
goto cleanup;
if (!virDomainObjIsActive(vm))
ret = 0;
else {
if (!virDomainObjIsActive(vm)) {
qemuReportError(VIR_ERR_OPERATION_INVALID,
"%s", _("domain is not running"));
goto endjob;
}
qemuDomainObjEnterMonitor(vm);
ret = qemuMonitorGetBlockExtent(priv->mon,
disk->info.alias,
&info->allocation);
qemuDomainObjExitMonitor(vm);
}
endjob:
if (qemuDomainObjEndJob(vm) == 0)
vm = NULL;
}
} else {
ret = 0;
}
@ -6637,8 +6678,8 @@ qemuDomainMigrateSetMaxDowntime(virDomainPtr dom,
}
VIR_DEBUG("Requesting migration downtime change to %llums", downtime);
priv->jobSignals |= QEMU_JOB_SIGNAL_MIGRATE_DOWNTIME;
priv->jobSignalsData.migrateDowntime = downtime;
priv->jobSignals |= QEMU_JOB_SIGNAL_MIGRATE_DOWNTIME;
ret = 0;
cleanup:
@ -6686,8 +6727,8 @@ qemuDomainMigrateSetMaxSpeed(virDomainPtr dom,
}
VIR_DEBUG("Requesting migration speed change to %luMbs", bandwidth);
priv->jobSignals |= QEMU_JOB_SIGNAL_MIGRATE_SPEED;
priv->jobSignalsData.migrateBandwidth = bandwidth;
priv->jobSignals |= QEMU_JOB_SIGNAL_MIGRATE_SPEED;
ret = 0;
cleanup:

View File

@ -648,7 +648,8 @@ qemuMigrationSetOffline(struct qemud_driver *driver,
static int
qemuMigrationProcessJobSignals(struct qemud_driver *driver,
virDomainObjPtr vm,
const char *job)
const char *job,
bool cleanup)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
int ret = -1;
@ -656,6 +657,8 @@ qemuMigrationProcessJobSignals(struct qemud_driver *driver,
if (!virDomainObjIsActive(vm)) {
qemuReportError(VIR_ERR_INTERNAL_ERROR, _("%s: %s"),
job, _("guest unexpectedly quit"));
if (cleanup)
priv->jobSignals = 0;
return -1;
}
@ -695,6 +698,34 @@ qemuMigrationProcessJobSignals(struct qemud_driver *driver,
qemuDomainObjExitMonitorWithDriver(driver, vm);
if (ret < 0)
VIR_WARN("Unable to set migration speed");
} else if (priv->jobSignals & QEMU_JOB_SIGNAL_BLKSTAT) {
qemuDomainObjEnterMonitorWithDriver(driver, vm);
ret = qemuMonitorGetBlockStatsInfo(priv->mon,
priv->jobSignalsData.statDevName,
&priv->jobSignalsData.blockStat->rd_req,
&priv->jobSignalsData.blockStat->rd_bytes,
&priv->jobSignalsData.blockStat->wr_req,
&priv->jobSignalsData.blockStat->wr_bytes,
&priv->jobSignalsData.blockStat->errs);
qemuDomainObjExitMonitorWithDriver(driver, vm);
*priv->jobSignalsData.statRetCode = ret;
priv->jobSignals ^= QEMU_JOB_SIGNAL_BLKSTAT;
if (ret < 0)
VIR_WARN("Unable to get block statistics");
} else if (priv->jobSignals & QEMU_JOB_SIGNAL_BLKINFO) {
qemuDomainObjEnterMonitorWithDriver(driver, vm);
ret = qemuMonitorGetBlockExtent(priv->mon,
priv->jobSignalsData.infoDevName,
&priv->jobSignalsData.blockInfo->allocation);
qemuDomainObjExitMonitorWithDriver(driver, vm);
*priv->jobSignalsData.infoRetCode = ret;
priv->jobSignals ^= QEMU_JOB_SIGNAL_BLKINFO;
if (ret < 0)
VIR_WARN("Unable to get block information");
} else {
ret = 0;
}
@ -788,12 +819,6 @@ int
qemuMigrationWaitForCompletion(struct qemud_driver *driver, virDomainObjPtr vm)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
priv->jobInfo.type = VIR_DOMAIN_JOB_UNBOUNDED;
while (priv->jobInfo.type == VIR_DOMAIN_JOB_UNBOUNDED) {
/* Poll every 50ms for progress & to allow cancellation */
struct timespec ts = { .tv_sec = 0, .tv_nsec = 50 * 1000 * 1000ull };
const char *job;
switch (priv->jobActive) {
@ -810,8 +835,17 @@ qemuMigrationWaitForCompletion(struct qemud_driver *driver, virDomainObjPtr vm)
job = _("job");
}
if (qemuMigrationProcessJobSignals(driver, vm, job) < 0)
priv->jobInfo.type = VIR_DOMAIN_JOB_UNBOUNDED;
while (priv->jobInfo.type == VIR_DOMAIN_JOB_UNBOUNDED) {
/* Poll every 50ms for progress & to allow cancellation */
struct timespec ts = { .tv_sec = 0, .tv_nsec = 50 * 1000 * 1000ull };
while (priv->jobSignals) {
if (qemuMigrationProcessJobSignals(driver, vm, job, false) < 0)
goto cleanup;
}
virCondSignal(&priv->signalCond);
if (qemuMigrationUpdateJobStatus(driver, vm, job) < 0)
goto cleanup;
@ -827,6 +861,11 @@ qemuMigrationWaitForCompletion(struct qemud_driver *driver, virDomainObjPtr vm)
}
cleanup:
while (priv->jobSignals) {
qemuMigrationProcessJobSignals(driver, vm, job, true);
}
virCondBroadcast(&priv->signalCond);
if (priv->jobInfo.type == VIR_DOMAIN_JOB_COMPLETED)
return 0;
else