[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v1 6/9] s390x: kvm: topology: interception of PTF instruction
|
From: |
Cornelia Huck |
|
Subject: |
Re: [PATCH v1 6/9] s390x: kvm: topology: interception of PTF instruction |
|
Date: |
Fri, 16 Jul 2021 13:56:29 +0200 |
|
User-agent: |
Notmuch/0.32.1 (https://notmuchmail.org) |
On Fri, Jul 16 2021, Pierre Morel <pmorel@linux.ibm.com> wrote:
> On 7/16/21 11:22 AM, Cornelia Huck wrote:
>> 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?
>
> yes,
>
>>
>> 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.
>
> Yes, PTF generated an OPERATION exception on old QEMU, but was not used
> by the guest if it has not the topology facility 11.
>
> So just as for STSI, I think we need the KVM_CAP_S390_CPU_TOPOLOGY I
> dropped because otherwise, now that the kernel will advertise facility
> 11, the guest will use it and it will get the exception that it should
> not get.
Ok, makes sense.
- [PATCH v1 4/9] s390x: Topology list entries and SYSIB 15.x.x, (continued)
- [PATCH v1 4/9] s390x: Topology list entries and SYSIB 15.x.x, Pierre Morel, 2021/07/14
- [PATCH v1 7/9] s390x: SCLP: reporting the maximum nested topology entries, Pierre Morel, 2021/07/14
- [PATCH v1 3/9] s390x: cpu topology: CPU topology objects and structures, Pierre Morel, 2021/07/14
- [PATCH v1 5/9] s390x: topology: implementating Store Topology System Information, Pierre Morel, 2021/07/14
- [PATCH v1 6/9] s390x: kvm: topology: interception of PTF instruction, Pierre Morel, 2021/07/14
- [PATCH v1 9/9] s390x: numa: implement NUMA for S390x, Pierre Morel, 2021/07/14
- [PATCH v1 8/9] s390x: numa: define drawers and books for NUMA, Pierre Morel, 2021/07/14