12:52 p.m.
See documentation in 1/3 for details.
Jiri Denemark (3):
Add a migration parameter for available bandwidth in switchover
virsh migrate: Add --available-switchover-bandwidth option
qemu: Add support for avail-switchover-bandwidth migration parameter
docs/manpages/virsh.rst | 12 ++++++++++++
include/libvirt/libvirt-domain.h | 18 ++++++++++++++++++
src/qemu/qemu_migration.h | 1 +
src/qemu/qemu_migration_params.c | 9 +++++++++
src/qemu/qemu_migration_params.h | 1 +
tools/virsh-domain.c | 13 +++++++++++++
6 files changed, 54 insertions(+)
--
2.48.1
12:52 p.m.
New subject: [PATCH v2 1/3] Add a migration parameter for available bandwidth in switchover
The new VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER parameter can be
used to override the estimated bandwidth that can be used for
transferring guest memory and device state once virtual CPUs are
stopped.
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
include/libvirt/libvirt-domain.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
index 2a4b81f4df..74016c6c46 100644
--- a/include/libvirt/libvirt-domain.h
+++ b/include/libvirt/libvirt-domain.h
@@ -1206,6 +1206,24 @@ typedef enum {
*/
# define VIR_MIGRATE_PARAM_BANDWIDTH_POSTCOPY "bandwidth.postcopy"
+/**
+ * VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER:
+ *
+ * virDomainMigrate* params field: the bandwidth (in MiB/s) available for the
+ * final phase of (pre-copy) migration during which CPUs are stopped and all
+ * the remaining memory and device state is transferred. Knowing this bandwidth
+ * is important for accurate estimation of the domain downtime and deciding
+ * the right moment for switching over. Normally this would be estimated based
+ * on the bandwidth used by migration, but this could be lower than the actual
+ * available bandwidth. Using this parameter to override the computed value may
+ * help with migration convergence when the migration would keep iterating over
+ * and over thinking there's not enough bandwidth to comply with the configured
+ * maximum downtime.
+ *
+ * Since: 11.1.0
+ */
+# define VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER
"bandwidth.avail.switchover"
+
/**
* VIR_MIGRATE_PARAM_GRAPHICS_URI:
*
--
2.48.1
12:52 p.m.
New subject: [PATCH v2 2/3] virsh migrate: Add --available-switchover-bandwidth option
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
docs/manpages/virsh.rst | 12 ++++++++++++
tools/virsh-domain.c | 13 +++++++++++++
2 files changed, 25 insertions(+)
diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst
index e801037c04..bf0436621b 100644
--- a/docs/manpages/virsh.rst
+++ b/docs/manpages/virsh.rst
@@ -3407,6 +3407,7 @@ migrate
[--parallel [--parallel-connections connections]]
[--bandwidth bandwidth] [--tls-destination hostname]
[--disks-uri URI] [--copy-storage-synchronous-writes]
+ [--available-switchover-bandwidth bandwidth]
Migrate domain to another host. Add *--live* for live migration; <--p2p>
for peer-2-peer migration; *--direct* for direct migration; or *--tunnelled*
@@ -3663,6 +3664,17 @@ the context of the existing socket because it is different from the
file
representation of the socket and the context is chosen by its creator (usually
by using *setsockcreatecon{,_raw}()* functions).
+Optional *--available-switchover-bandwidth* overrides the automatically
+computed bandwidth (in MiB/s) available for the final phase of (pre-copy)
+migration during which CPUs are stopped and all the remaining memory and device
+state is transferred. Knowing this bandwidth is important for accurate
+estimation of the domain downtime and deciding the right moment for switching
+over. Normally this would be estimated based on the bandwidth used by
+migration, but this could be lower than the actual available bandwidth. Using
+this option may help with migration convergence when the migration would keep
+iterating over and over thinking there's not enough bandwidth to comply with
+the configured maximum downtime.
+
migrate-compcache
-----------------
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index 546db955a9..f3da2f903f 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -10788,6 +10788,10 @@ static const vshCmdOptDef opts_migrate[] = {
.type = VSH_OT_INT,
.help = N_("compress level for zstd compression")
},
+ {.name = "available-switchover-bandwidth",
+ .type = VSH_OT_INT,
+ .help = N_("bandwidth (in MiB/s) available for the final phase of
migration")
+ },
{.name = NULL}
};
@@ -11102,6 +11106,15 @@ doMigrate(void *opaque)
VIR_MIGRATE_PARAM_TLS_DESTINATION, opt) < 0)
goto save_error;
+ if ((rv = vshCommandOptULongLong(ctl, cmd,
"available-switchover-bandwidth", &ullOpt)) < 0) {
+ goto out;
+ } else if (rv > 0) {
+ if (virTypedParamsAddULLong(¶ms, &nparams, &maxparams,
+ VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER,
+ ullOpt) < 0)
+ goto save_error;
+ }
+
if (flags & VIR_MIGRATE_PEER2PEER || vshCommandOptBool(cmd, "direct"))
{
if (virDomainMigrateToURI3(dom, desturi, params, nparams, flags) == 0)
data->ret = 0;
--
2.48.1
12:52 p.m.
New subject: [PATCH v2 3/3] qemu: Add support for avail-switchover-bandwidth migration parameter
Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com>
---
src/qemu/qemu_migration.h | 1 +
src/qemu/qemu_migration_params.c | 9 +++++++++
src/qemu/qemu_migration_params.h | 1 +
3 files changed, 11 insertions(+)
diff --git a/src/qemu/qemu_migration.h b/src/qemu/qemu_migration.h
index 4b7ef9688a..efe1b9e88a 100644
--- a/src/qemu/qemu_migration.h
+++ b/src/qemu/qemu_migration.h
@@ -92,6 +92,7 @@
VIR_MIGRATE_PARAM_COMPRESSION_ZSTD_LEVEL, VIR_TYPED_PARAM_INT, \
VIR_MIGRATE_PARAM_TLS_DESTINATION, VIR_TYPED_PARAM_STRING, \
VIR_MIGRATE_PARAM_DISKS_URI, VIR_TYPED_PARAM_STRING, \
+ VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER, VIR_TYPED_PARAM_ULLONG, \
NULL
diff --git a/src/qemu/qemu_migration_params.c b/src/qemu/qemu_migration_params.c
index 98822012cc..c10660d6f2 100644
--- a/src/qemu/qemu_migration_params.c
+++ b/src/qemu/qemu_migration_params.c
@@ -128,6 +128,7 @@ VIR_ENUM_IMPL(qemuMigrationParam,
"multifd-compression",
"multifd-zlib-level",
"multifd-zstd-level",
+ "avail-switchover-bandwidth",
);
typedef struct _qemuMigrationParamsAlwaysOnItem qemuMigrationParamsAlwaysOnItem;
@@ -266,6 +267,11 @@ static const qemuMigrationParamsTPMapItem qemuMigrationParamsTPMap[]
= {
{.typedParam = VIR_MIGRATE_PARAM_TLS_DESTINATION,
.param = QEMU_MIGRATION_PARAM_TLS_HOSTNAME,
.party = QEMU_MIGRATION_SOURCE},
+
+ {.typedParam = VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER,
+ .unit = 1024 * 1024, /* MiB/s */
+ .param = QEMU_MIGRATION_PARAM_AVAIL_SWITCHOVER_BANDWIDTH,
+ .party = QEMU_MIGRATION_SOURCE},
};
static const qemuMigrationParamInfoItem qemuMigrationParamInfo[] = {
@@ -318,6 +324,9 @@ static const qemuMigrationParamInfoItem qemuMigrationParamInfo[] = {
[QEMU_MIGRATION_PARAM_MULTIFD_ZSTD_LEVEL] = {
.type = QEMU_MIGRATION_PARAM_TYPE_INT,
},
+ [QEMU_MIGRATION_PARAM_AVAIL_SWITCHOVER_BANDWIDTH] = {
+ .type = QEMU_MIGRATION_PARAM_TYPE_ULL,
+ },
};
G_STATIC_ASSERT(G_N_ELEMENTS(qemuMigrationParamInfo) == QEMU_MIGRATION_PARAM_LAST);
diff --git a/src/qemu/qemu_migration_params.h b/src/qemu/qemu_migration_params.h
index df67f1fb92..17fc63f527 100644
--- a/src/qemu/qemu_migration_params.h
+++ b/src/qemu/qemu_migration_params.h
@@ -64,6 +64,7 @@ typedef enum {
QEMU_MIGRATION_PARAM_MULTIFD_COMPRESSION,
QEMU_MIGRATION_PARAM_MULTIFD_ZLIB_LEVEL,
QEMU_MIGRATION_PARAM_MULTIFD_ZSTD_LEVEL,
+ QEMU_MIGRATION_PARAM_AVAIL_SWITCHOVER_BANDWIDTH,
QEMU_MIGRATION_PARAM_LAST
} qemuMigrationParam;
--
2.48.1
6:12 p.m.
New subject: [PATCH v2 0/3] qemu: Add support for avail-switchover-bandwidth
migration parameter
On 1/23/25 11:52, Jiri Denemark wrote:
See documentation in 1/3 for details.
Jiri Denemark (3):
Add a migration parameter for available bandwidth in switchover
virsh migrate: Add --available-switchover-bandwidth option
qemu: Add support for avail-switchover-bandwidth migration parameter
docs/manpages/virsh.rst | 12 ++++++++++++
include/libvirt/libvirt-domain.h | 18 ++++++++++++++++++
src/qemu/qemu_migration.h | 1 +
src/qemu/qemu_migration_params.c | 9 +++++++++
src/qemu/qemu_migration_params.h | 1 +
tools/virsh-domain.c | 13 +++++++++++++
6 files changed, 54 insertions(+)
Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com>
Michal
6
days inactive
7
days old
4 comments
2 participants
participants (2)
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Jiri Denemark -
Michal Prívozník