Re: [libvirt] [PATCHv3 05/43] snapshot: only pass snapshot to qemu command line when reverting

Changing the current vm, and writing that change to the file system, all before a new qemu starts, is risky; it's hard to roll back if starting the new qemu fails for some reason. Instead of abusing vm->current_snapshot and making the command line generator decide whether the current snapshot warrants using -loadvm, it is better to just directly pass a snapshot all the way through the call chain if it is to be loaded. This frees up the last use of snapshot->def->active for qemu's use, so the next patch can repurpose that field for tracking which snapshot is current. * src/qemu/qemu_command.c (qemuBuildCommandLine): Don't use active field of snapshot. * src/qemu/qemu_process.c (qemuProcessStart): Add a parameter. * src/qemu/qemu_process.h (qemuProcessStart): Update prototype. * src/qemu/qemu_migration.c (qemuMigrationPrepareAny): Update callers. * src/qemu/qemu_driver.c (qemudDomainCreate) (qemuDomainSaveImageStartVM, qemuDomainObjStart) (qemuDomainRevertToSnapshot): Likewise. (qemuDomainSnapshotSetCurrentActive) (qemuDomainSnapshotSetCurrentInactive): Delete unused functions. --- src/qemu/qemu_command.c | 7 ++--- src/qemu/qemu_driver.c | 47 ++++---------------------------------------- src/qemu/qemu_migration.c | 2 +- src/qemu/qemu_process.c | 10 +------- src/qemu/qemu_process.h | 1 + 5 files changed, 12 insertions(+), 55 deletions(-)