When using the mapped-ram migration capability, direct IO is
enabled by setting the "direct-io" migration parameter to
"true" and passing QEMU an additional fd with O_DIRECT set.
Signed-off-by: Jim Fehlig <jfehlig@xxxxxxxx>
---
src/qemu/qemu_migration.c | 11 ++++++-----
src/qemu/qemu_process.c | 30 ++++++++++++++++++++++++++----
src/qemu/qemu_process.h | 6 ++++--
3 files changed, 36 insertions(+), 11 deletions(-)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
index daa42bcfe4..56199c616b 100644
--- a/src/qemu/qemu_migration.c
+++ b/src/qemu/qemu_migration.c
@@ -2948,7 +2948,8 @@ qemuMigrationDstPrepareCleanup(virQEMUDriver *driver,
}
static qemuProcessIncomingDef *
-qemuMigrationDstPrepare(virDomainObj *vm,
+qemuMigrationDstPrepare(virQEMUDriver *driver,
+ virDomainObj *vm,
bool tunnel,
const char *protocol,
const char *listenAddress,
@@ -3008,8 +3009,8 @@ qemuMigrationDstPrepare(virDomainObj *vm,
migrateFrom = g_strdup_printf(incFormat, protocol, listenAddress, port);
}
- return qemuProcessIncomingDefNew(vm, listenAddress,
- migrateFrom, fd, NULL, NULL);
+ return qemuProcessIncomingDefNew(driver, vm, listenAddress,
+ migrateFrom, fd, NULL, NULL, NULL);
}
@@ -3151,7 +3152,7 @@ qemuMigrationDstPrepareActive(virQEMUDriver *driver,
goto error;
stopProcess = true;
- if (!(incoming = qemuMigrationDstPrepare(vm, tunnel, protocol,
+ if (!(incoming = qemuMigrationDstPrepare(driver, vm, tunnel, protocol,
listenAddress, port,
&dataFD[0])))
goto error;
@@ -3522,7 +3523,7 @@ qemuMigrationDstPrepareResume(virQEMUDriver *driver,
priv->origname = g_strdup(origname);
- if (!(incoming = qemuMigrationDstPrepare(vm, false, protocol,
+ if (!(incoming = qemuMigrationDstPrepare(driver, vm, false, protocol,
listenAddress, port, NULL)))
goto cleanup;
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index b02cd84aff..e10894d0f9 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -4694,13 +4694,16 @@ qemuProcessIncomingDefFree(qemuProcessIncomingDef *inc)
* qemuProcessIncomingDefFree will NOT close it.
*/
qemuProcessIncomingDef *
-qemuProcessIncomingDefNew(virDomainObj *vm,
+qemuProcessIncomingDefNew(virQEMUDriver *driver,
+ virDomainObj *vm,
const char *listenAddress,
const char *migrateFrom,
int *fd,
const char *path,
- virQEMUSaveData *data)
+ virQEMUSaveData *data,
+ qemuMigrationParams *migParams)
{
+ g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
qemuDomainObjPrivate *priv = vm->privateData;
qemuProcessIncomingDef *inc = NULL;
@@ -4715,10 +4718,28 @@ qemuProcessIncomingDefNew(virDomainObj *vm,
size_t offset = sizeof(virQEMUSaveHeader) + data->header.data_len;
if (data->header.features & QEMU_SAVE_FEATURE_MAPPED_RAM) {
+ bool directio = false;
unsigned int fdsetId;
inc->fdPassMigrate = qemuFDPassNew("migrate", priv);
- qemuFDPassAddFD(inc->fdPassMigrate, fd, "-buffered-fd");
+ /* When using directio with mapped-ram, qemu needs an fd without
+ * O_DIRECT set for reading small bits of unaligned state. */
+ if (qemuMigrationParamsGetBool(migParams,
+ QEMU_MIGRATION_PARAM_DIRECT_IO,
+ &directio) < 0)
+ goto error;
+
+ if (directio) {
+ VIR_AUTOCLOSE bufferedFd = -1;
+
+ if ((bufferedFd = qemuDomainOpenFile(cfg, NULL, path, O_RDONLY, NULL)) < 0)
+ goto error;
+
+ qemuFDPassAddFD(inc->fdPassMigrate, &bufferedFd, "-buffered-fd");
+ qemuFDPassAddFD(inc->fdPassMigrate, fd, "-directio-fd");
+ } else {
+ qemuFDPassAddFD(inc->fdPassMigrate, fd, "-buffered-fd");
+ }
qemuFDPassGetId(inc->fdPassMigrate, &fdsetId);
inc->uri = g_strdup_printf("file:/dev/fdset/%u,offset=%#lx", fdsetId, offset);
} else {
@@ -8377,7 +8398,8 @@ qemuProcessStartWithMemoryState(virConnectPtr conn,
int rc = 0;
int ret = -1;
- incoming = qemuProcessIncomingDefNew(vm, NULL, "stdio", fd, path, data);
+ incoming = qemuProcessIncomingDefNew(driver, vm, NULL, "stdio",
+ fd, path, data, migParams);
if (!incoming)
return -1;
diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
index 93699da8bd..0e6aedf75d 100644
--- a/src/qemu/qemu_process.h
+++ b/src/qemu/qemu_process.h
@@ -58,12 +58,14 @@ struct _qemuProcessIncomingDef {
const char *path; /* path associated with fd */
};
-qemuProcessIncomingDef *qemuProcessIncomingDefNew(virDomainObj *vm,
+qemuProcessIncomingDef *qemuProcessIncomingDefNew(virQEMUDriver *driver,
+ virDomainObj *vm,
const char *listenAddress,
const char *migrateFrom,
int *fd,
const char *path,
- virQEMUSaveData *data);
+ virQEMUSaveData *data,
+ qemuMigrationParams *migParams);
void qemuProcessIncomingDefFree(qemuProcessIncomingDef *inc);
--
2.35.3
