s390x cpu model improvements for KVM

[Qemu-devel] [PATCH v1 0/2] s390x cpu model improvements for KVM

Posted by David Hildenbrand 6 years, 10 months ago

We should properly forward the CPUID format bit. CPU model
detection on systems without IBC might select a model with a wrong
CPU type (esp. selecting the business class (BC) model on an enterprise
class (EC) machine). So let's improve that, too.

I am also preparing a patch to properly indicate the correct cpu type
to the guest via STORE CPU ID and STORE HYPERVISOR INFORMATION for the
TCG case, but will send that separately after I tested it (want to write a
kvm-unit-test for STORE CPU ID).

David Hildenbrand (2):
  s390x/cpumodel: take care of the cpuid format bit for KVM
  s390x/cpumodel: improve defintion search without an IBC

 target/s390x/cpu_models.c | 10 ++++++++++
 target/s390x/cpu_models.h | 10 +++++++---
 target/s390x/kvm.c        |  1 +
 3 files changed, 18 insertions(+), 3 deletions(-)

-- 
2.9.3

Re: [Qemu-devel] [PATCH v1 0/2] s390x cpu model improvements for KVM

Posted by Christian Borntraeger 6 years, 10 months ago

On 05/31/2017 09:34 PM, David Hildenbrand wrote:
> We should properly forward the CPUID format bit. CPU model
> detection on systems without IBC might select a model with a wrong
> CPU type (esp. selecting the business class (BC) model on an enterprise
> class (EC) machine). So let's improve that, too.
> 
> I am also preparing a patch to properly indicate the correct cpu type
> to the guest via STORE CPU ID and STORE HYPERVISOR INFORMATION for the
> TCG case, but will send that separately after I tested it (want to write a
> kvm-unit-test for STORE CPU ID).
> 
> David Hildenbrand (2):
>   s390x/cpumodel: take care of the cpuid format bit for KVM
>   s390x/cpumodel: improve defintion search without an IBC
> 
>  target/s390x/cpu_models.c | 10 ++++++++++
>  target/s390x/cpu_models.h | 10 +++++++---
>  target/s390x/kvm.c        |  1 +
>  3 files changed, 18 insertions(+), 3 deletions(-)
> 

I like both patches in terms of "yes, its the right thing to do".
Jason can you have a look? I might need some days to catch up
with other things before I can look into the patches.

Re: [Qemu-devel] [PATCH v1 0/2] s390x cpu model improvements for KVM

Posted by Jason J. Herne 6 years, 10 months ago

On 06/01/2017 06:10 AM, Christian Borntraeger wrote:
> On 05/31/2017 09:34 PM, David Hildenbrand wrote:
>> We should properly forward the CPUID format bit. CPU model
>> detection on systems without IBC might select a model with a wrong
>> CPU type (esp. selecting the business class (BC) model on an enterprise
>> class (EC) machine). So let's improve that, too.
>>
>> I am also preparing a patch to properly indicate the correct cpu type
>> to the guest via STORE CPU ID and STORE HYPERVISOR INFORMATION for the
>> TCG case, but will send that separately after I tested it (want to write a
>> kvm-unit-test for STORE CPU ID).
>>
>> David Hildenbrand (2):
>>   s390x/cpumodel: take care of the cpuid format bit for KVM
>>   s390x/cpumodel: improve defintion search without an IBC
>>
>>  target/s390x/cpu_models.c | 10 ++++++++++
>>  target/s390x/cpu_models.h | 10 +++++++---
>>  target/s390x/kvm.c        |  1 +
>>  3 files changed, 18 insertions(+), 3 deletions(-)
>>
>
> I like both patches in terms of "yes, its the right thing to do".
> Jason can you have a look? I might need some days to catch up
> with other things before I can look into the patches.
>

David answered the one question I had. So, as far as I can see, this
is ok.

Acked-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>

-- 
-- Jason J. Herne (jjherne@linux.vnet.ibm.com)