Re: [PATCH v1 6/9] s390x: kvm: topology: interception of PTF instruction

[Cornelia Huck]

On Wed, Jul 14 2021, Pierre Morel <pmorel@linux.ibm.com> wrote:

> Interception of the PTF instruction depending on the new
> KVM_CAP_S390_CPU_TOPOLOGY KVM extension.

Wasn't that the capability that you dropped?

Is PTF supposed to be always intercepting? If that isn't configurable,
wouldn't older QEMUs generate exceptions for it? I'm a bit confused.

>
> A global value is used to remember if a Topology change occured since
> the last interception of a PTF instruction with function code 0.
>
> Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> ---
>  hw/s390x/cpu-topology.c            | 19 +++++++++++
>  include/hw/s390x/cpu-topology.h    |  8 +++++
>  include/hw/s390x/s390-virtio-ccw.h |  1 +
>  target/s390x/cpu.c                 |  4 +++
>  target/s390x/cpu.h                 |  1 +
>  target/s390x/kvm/kvm.c             | 52 ++++++++++++++++++++++++++++++
>  6 files changed, 85 insertions(+)