Re: [libvirt] [PATCH 5/6] qemu: migration: warn if migrating with host-passthrough

From: "Collin L. Walling" <walling(a)linux.vnet.ibm.com&gt; Warn the user when migrating a guest that is using the host-passthrough cpu mode. host-passthrough is not migration safe because the host hypervisor is not attempting to block features that may not exist on the destination host. Signed-off-by: Collin L. Walling <walling(a)linux.vnet.ibm.com&gt; Signed-off-by: Jason J. Herne <jjherne(a)linux.vnet.ibm.com&gt; --- src/qemu/qemu_migration.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index d4a55d8..f721de7 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -3151,6 +3151,10 @@ qemuMigrationBeginPhase(virQEMUDriverPtr driver, if (priv->job.asyncJob == QEMU_ASYNC_JOB_MIGRATION_OUT) qemuMigrationJobSetPhase(driver, vm, QEMU_MIGRATION_PHASE_BEGIN3); + if (vm->def->cpu && vm->def->cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) + VIR_WARN("cpu mode 'host-passthrough' may fail migration if destination" + " machine is running an older cpu model."); +

if (!qemuMigrationIsAllowed(driver, vm, true, flags)) goto cleanup;