Re: [PATCH v5 3/9] target/s390x: add zpci-interp to cpu models

From: Thomas Huth <thuth@redhat.com>
To: Matthew Rosato <mjrosato@linux.ibm.com>,
	qemu-s390x@nongnu.org, david@redhat.com
Cc: alex.williamson@redhat.com, schnelle@linux.ibm.com,
	cohuck@redhat.com, farman@linux.ibm.com, pmorel@linux.ibm.com,
	richard.henderson@linaro.org, pasic@linux.ibm.com,
	borntraeger@linux.ibm.com, mst@redhat.com, pbonzini@redhat.com,
	qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [PATCH v5 3/9] target/s390x: add zpci-interp to cpu models
Date: Wed, 18 May 2022 10:02:34 +0200	[thread overview]
Message-ID: <159d28b9-3607-dd66-975b-bf004752cda4@redhat.com> (raw)
In-Reply-To: <f7ca365a-1e7e-d0a8-8a0e-5cf744cd1d20@redhat.com>

On 18/05/2022 10.01, Thomas Huth wrote:
> On 04/04/2022 20.17, Matthew Rosato wrote:
>> The zpci-interp feature is used to specify whether zPCI interpretation is
>> to be used for this guest.
>>
>> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
>> ---
>>   hw/s390x/s390-virtio-ccw.c          | 1 +
>>   target/s390x/cpu_features_def.h.inc | 1 +
>>   target/s390x/gen-features.c         | 2 ++
>>   target/s390x/kvm/kvm.c              | 1 +
>>   4 files changed, 5 insertions(+)
>>
>> diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
>> index 90480e7cf9..b190234308 100644
>> --- a/hw/s390x/s390-virtio-ccw.c
>> +++ b/hw/s390x/s390-virtio-ccw.c
>> @@ -805,6 +805,7 @@ static void 
>> ccw_machine_6_2_instance_options(MachineState *machine)
>>       static const S390FeatInit qemu_cpu_feat = { S390_FEAT_LIST_QEMU_V6_2 };
>>       ccw_machine_7_0_instance_options(machine);
>> +    s390_cpudef_featoff_greater(14, 1, S390_FEAT_ZPCI_INTERP);
>>       s390_set_qemu_cpu_model(0x3906, 14, 2, qemu_cpu_feat);
>>   }
>> diff --git a/target/s390x/cpu_features_def.h.inc 
>> b/target/s390x/cpu_features_def.h.inc
>> index e86662bb3b..4ade3182aa 100644
>> --- a/target/s390x/cpu_features_def.h.inc
>> +++ b/target/s390x/cpu_features_def.h.inc
>> @@ -146,6 +146,7 @@ DEF_FEAT(SIE_CEI, "cei", SCLP_CPU, 43, "SIE: 
>> Conditional-external-interception f
>>   DEF_FEAT(DAT_ENH_2, "dateh2", MISC, 0, "DAT-enhancement facility 2")
>>   DEF_FEAT(CMM, "cmm", MISC, 0, "Collaborative-memory-management facility")
>>   DEF_FEAT(AP, "ap", MISC, 0, "AP instructions installed")
>> +DEF_FEAT(ZPCI_INTERP, "zpci-interp", MISC, 0, "zPCI interpretation")
>>   /* Features exposed via the PLO instruction. */
>>   DEF_FEAT(PLO_CL, "plo-cl", PLO, 0, "PLO Compare and load (32 bit in 
>> general registers)")
>> diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
>> index 22846121c4..9db6bd545e 100644
>> --- a/target/s390x/gen-features.c
>> +++ b/target/s390x/gen-features.c
>> @@ -554,6 +554,7 @@ static uint16_t full_GEN14_GA1[] = {
>>       S390_FEAT_HPMA2,
>>       S390_FEAT_SIE_KSS,
>>       S390_FEAT_GROUP_MULTIPLE_EPOCH_PTFF,
>> +    S390_FEAT_ZPCI_INTERP,
>>   };
>>   #define full_GEN14_GA2 EmptyFeat
>> @@ -650,6 +651,7 @@ static uint16_t default_GEN14_GA1[] = {
>>       S390_FEAT_GROUP_MSA_EXT_8,
>>       S390_FEAT_MULTIPLE_EPOCH,
>>       S390_FEAT_GROUP_MULTIPLE_EPOCH_PTFF,
>> +    S390_FEAT_ZPCI_INTERP,
>>   };
> 
> If you add something to the default model, I think you also need to add some 
> compatibility handling to the machine types. See e.g. commit 84176c7906f as 
> an example.

Ah, never mind, it's there some lines earlier in the patch ... I guess I did 
not have not enough coffee today yet...

  Thomas