Re: [libvirt] [PATCH 0/4] qemu: Use host-model CPU on s390 by default

On s390 machines host-passthrough and host-model CPUs result in the same guest ABI (with QEMU new enough to be able to tell us what "host" CPU is expanded to, which was implemented around 2.9.0). So instead of using host-passthrough CPU when there's no CPU specified in a domain XML we can safely use host-model and benefit from CPU compatibility checks during migration, snapshot restore and similar operations. This series applies on top of "qemu: Store default CPU in domain XML" which is already acked, but it's waiting for a QEMU patch to be applied to 4.2.0. You can fetch both series at once using git fetch https://gitlab.com/jirkade/libvirt cpu-default-type Jiri Denemark (4): cpu_conf: Fix default value for CPU match attribute cpu_conf: Don't format empty model for host-model CPUs cpu_s390: Don't check match attribute for host-model CPUs qemu: Use host-model CPU on s390 by default src/conf/cpu_conf.c | 25 ++++---------- src/conf/cpu_conf.h | 2 +- src/cpu/cpu_s390.c | 18 +++++----- src/qemu/qemu_domain.c | 33 ++++++++++++------- .../ppc64-host+guest-compat-none.xml | 4 +-- ...t-cpu-kvm-ccw-virtio-4.2.s390x-latest.args | 4 ++- .../cpu-check-default-partial.xml | 4 +-- .../cpu-host-model-features.xml | 1 - ...lt-cpu-kvm-ccw-virtio-4.2.s390x-latest.xml | 2 +- 9 files changed, 45 insertions(+), 48 deletions(-)