[libvirt] [PATCH 1/2] Don't verify CPU features with host-passthrough

Commit fba6bc4 introduced the non-migratable invtsc feature, breaking save/migration with host-model and host-passthrough. On hosts with this feature present it was automatically included in the CPU definition, regardless of QEMU support. Commit de0aeaf stopped including it by default for host-model, but failed to fix host-passthrough. This commit ignores checking of CPU features with host-passthrough, since we don't pass them to QEMU (only -cpu host is passed), allowing domains using host-passthrough that were saved with the broken version of libvirtd to be restored. https://bugzilla.redhat.com/show_bug.cgi?id=1147584 --- src/qemu/qemu_migration.c | 22 ++++++++++++---------- src/qemu/qemu_process.c | 5 +++++ 2 files changed, 17 insertions(+), 10 deletions(-) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 6b38592..284cd5a 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1714,18 +1714,20 @@ qemuMigrationIsAllowed(virQEMUDriverPtr driver, virDomainObjPtr vm, return false; } - for (i = 0; def->cpu && i < def->cpu->nfeatures; i++) { - virCPUFeatureDefPtr feature = &def->cpu->features[i]; + if (def->cpu && def->cpu->mode != VIR_CPU_MODE_HOST_PASSTHROUGH) { + for (i = 0; i < def->cpu->nfeatures; i++) { + virCPUFeatureDefPtr feature = &def->cpu->features[i]; - if (feature->policy != VIR_CPU_FEATURE_REQUIRE) - continue; + if (feature->policy != VIR_CPU_FEATURE_REQUIRE) + continue; - /* QEMU blocks migration and save with invariant TSC enabled */ - if (STREQ(feature->name, "invtsc")) { - virReportError(VIR_ERR_OPERATION_INVALID, - _("domain has CPU feature: %s"), - feature->name); - return false; + /* QEMU blocks migration and save with invariant TSC enabled */ + if (STREQ(feature->name, "invtsc")) { + virReportError(VIR_ERR_OPERATION_INVALID, + _("domain has CPU feature: %s"), + feature->name); + return false; + } } } diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 1b8931e..ca78aac 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -3787,6 +3787,11 @@ qemuProcessVerifyGuestCPU(virQEMUDriverPtr driver, bool ret = false; size_t i; + /* no features are passed to QEMU with -cpu host + * so it makes no sense to verify them */ + if (def->cpu->mode == VIR_CPU_MODE_HOST_PASSTHROUGH) + return true; + switch (arch) { case VIR_ARCH_I686: case VIR_ARCH_X86_64: -- 1.8.5.5