9:53 a.m.
From: "Michael R. Hines" <mrhines(a)us.ibm.com>
This patch adds support for RDMA protocol in migration URIs.
USAGE: $ virsh migrate --live --migrateuri rdma://hostname domain
qemu+ssh://hostname/system
Since libvirt runs QEMU in a pretty restricted environment, several
files needs to be added to cgroup_device_acl (in qemu.conf) for QEMU to
be able to access the host's infiniband hardware. Full documenation of
the feature can be found on QEMU wiki:
http://wiki.qemu.org/Features/RDMALiveMigration
Signed-off-by: Michael R. Hines <mrhines(a)us.ibm.com>
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
Notes:
The question is whether the IB devices should be added to
cgroup_device_acl by default or not...
Version 3:
- moved capabilities code into a separate patch
- got rid of migration URI hacks
- removed hacks that disabled IPv6 with RDMA
- moved refactoring into a dedicated patch
- documented IB devices which need to be added to cgroup acl in
qemu.conf
- forbid RDMA migrations unless memory hard limit is set until we
have a better plan for setting limits for mlock
- set QEMU's RLIMIT_MEMLOCK to memory hard_limit before starting
RDMA migration
- check if RDMA migration is supported by source QEMU before trying
to migrate
src/qemu/qemu.conf | 8 ++++++++
src/qemu/qemu_command.c | 8 ++++++++
src/qemu/qemu_migration.c | 39 +++++++++++++++++++++++++++++++++++++--
3 files changed, 53 insertions(+), 2 deletions(-)
diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf
index 79bba36..92ca715 100644
--- a/src/qemu/qemu.conf
+++ b/src/qemu/qemu.conf
@@ -274,6 +274,14 @@
# "/dev/ptmx", "/dev/kvm", "/dev/kqemu",
# "/dev/rtc","/dev/hpet", "/dev/vfio/vfio"
#]
+#
+# RDMA migration requires the following extra files to be added to the list:
+# "/dev/infiniband/rdma_cm",
+# "/dev/infiniband/issm0",
+# "/dev/infiniband/issm1",
+# "/dev/infiniband/umad0",
+# "/dev/infiniband/umad1",
+# "/dev/infiniband/uverbs0"
# The default format for Qemu/KVM guest save images is raw; that is, the
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index a892d99..fceed62 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -9399,6 +9399,14 @@ qemuBuildCommandLine(virConnectPtr conn,
goto error;
}
virCommandAddArg(cmd, migrateFrom);
+ } else if (STRPREFIX(migrateFrom, "rdma")) {
+ if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MIGRATE_RDMA)) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("incoming RDMA migration is not supported "
+ "with this QEMU binary"));
+ goto error;
+ }
+ virCommandAddArg(cmd, migrateFrom);
} else if (STREQ(migrateFrom, "stdio")) {
if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_MIGRATE_QEMU_FD)) {
virCommandAddArgFormat(cmd, "fd:%d", migrateFd);
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index d0e2653..b59e94d 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -56,6 +56,7 @@
#include "virhook.h"
#include "virstring.h"
#include "virtypedparam.h"
+#include "virprocess.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -2653,6 +2654,13 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
QEMU_MIGRATION_COOKIE_NBD)))
goto cleanup;
+ if (STREQ(protocol, "rdma") && !vm->def->mem.hard_limit) {
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("cannot start RDMA migration with no memory hard "
+ "limit set"));
+ goto cleanup;
+ }
+
if (qemuMigrationJobStart(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0)
goto cleanup;
qemuMigrationJobSetPhase(driver, vm, QEMU_MIGRATION_PHASE_PREPARE);
@@ -2696,6 +2704,11 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
QEMU_ASYNC_JOB_MIGRATION_IN) < 0)
goto stop;
+ if (STREQ(protocol, "rdma") &&
+ virProcessSetMaxMemLock(vm->pid, vm->def->mem.hard_limit << 10)
< 0) {
+ goto stop;
+ }
+
if (mig->lockState) {
VIR_DEBUG("Received lockstate %s", mig->lockState);
VIR_FREE(priv->lockState);
@@ -2926,7 +2939,8 @@ qemuMigrationPrepareDirect(virQEMUDriverPtr driver,
if (!(uri = qemuMigrationParseURI(uri_in, &well_formed_uri)))
goto cleanup;
- if (STRNEQ(uri->scheme, "tcp")) {
+ if (STRNEQ(uri->scheme, "tcp") &&
+ STRNEQ(uri->scheme, "rdma")) {
virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED,
_("unsupported scheme %s in migration URI %s"),
uri->scheme, uri_in);
@@ -3545,6 +3559,11 @@ qemuMigrationRun(virQEMUDriverPtr driver,
switch (spec->destType) {
case MIGRATION_DEST_HOST:
+ if (STREQ(spec->dest.host.protocol, "rdma") &&
+ virProcessSetMaxMemLock(vm->pid, vm->def->mem.hard_limit <<
10) < 0) {
+ qemuDomainObjExitMonitor(driver, vm);
+ goto cleanup;
+ }
ret = qemuMonitorMigrateToHost(priv->mon, migrate_flags,
spec->dest.host.protocol,
spec->dest.host.name,
@@ -3717,7 +3736,23 @@ static int doNativeMigrate(virQEMUDriverPtr driver,
if (!(uribits = qemuMigrationParseURI(uri, NULL)))
return -1;
- if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATE_QEMU_FD))
+ if (STREQ(uribits->scheme, "rdma")) {
+ if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATE_RDMA)) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("outgoing RDMA migration is not supported "
+ "with this QEMU binary"));
+ return -1;
+ }
+ if (!vm->def->mem.hard_limit) {
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("cannot start RDMA migration with no memory hard
"
+ "limit set"));
+ return -1;
+ }
+ }
+
+ if (virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_MIGRATE_QEMU_FD) &&
+ STRNEQ(uribits->scheme, "rdma"))
spec.destType = MIGRATION_DEST_CONNECT_HOST;
else
spec.destType = MIGRATION_DEST_HOST;
--
2.1.0