On 15.02.2018 17:08, David Hildenbrand wrote:
> On 15.02.2018 16:43, Janosch Frank wrote:
>> use_cmma in kvm_arch means that the vm is allowed to use cmma, whereas
>> use_cmma in the mm context means it has been used before. Let's rename
>> the kvm_arch one to has_cmma
>
> Unfortunately all naming related to CMM(A) is already screwed up.
>
> If the guest can issue the ESSA instruction, it has the CMM facility. We
> used to provide it to him by enabling the CMMA control - the
> "interpretation facility". We could right now fully emulate it (which is
> what we do when we dirty track changes).
>
> At least in the CPU model we did it right. (the feature is called "cmm")
>
> But anyhow, we only provide the CMM facility to the guest right now if
> we have CMMA, so keeping the name "cmma" here is not completely wrong.
>
>>
>> Also let's introduce has_pfmfi, so we can remove the pfmfi disablement
>
> Mixed feelings. has_pfmfi sounds more like "this guest has the PFMFI
> feature", which is something related to vSIE. It is really more
> "use_pfmfi". Because we provide the PFMF instruction either way (by
> emulating it - it belongs to edat1).
>
> Can we name this "use_cmma" and "use_pfmfi" and "use_skf", because that
> is actually what we do?
As long as we have a difference between the arch and the context one and
the implementation of the patches are not a problem, sure.
We could also invert them and use emulate_pfmf or intercept_* which is
more specific about what we actually (don't) do.
>
> The thing in the mm context should rather be renamed to "uses_cmm(a)" or
> "used_cmm(a)".
Yes, I like uses more, the rest of the gang likes used, now feel free to
propose something entirely different :)
If there's not much that speaks against the first two patches, I'd spin
them off to merge them earlier, the use_cmma cleanup has been on my list
for a long time. Thoughts?
>
>> when we activate cmma and rather not activate it in the first place.
>>
>> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
>> ---
>> arch/s390/include/asm/kvm_host.h | 3 ++-
>> arch/s390/kvm/kvm-s390.c | 25 +++++++++++++------------
>> arch/s390/kvm/priv.c | 2 +-
>> 3 files changed, 16 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>> index afb0f08..b768754 100644
>> --- a/arch/s390/include/asm/kvm_host.h
>> +++ b/arch/s390/include/asm/kvm_host.h
>> @@ -791,7 +791,8 @@ struct kvm_arch{
>> unsigned long mem_limit;
>> int css_support;
>> int use_irqchip;
>> - int use_cmma;
>> + int has_cmma;
>> + int has_pfmfi;
>> int user_cpu_state_ctrl;
>> int user_sigp;
>> int user_stsi;
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 4a2d68c..781aaf0 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -655,7 +655,9 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
>> VM_EVENT(kvm, 3, "%s", "ENABLE: CMMA support");
>> mutex_lock(&kvm->lock);
>> if (!kvm->created_vcpus) {
>> - kvm->arch.use_cmma = 1;
>> + kvm->arch.has_cmma = 1;
>> + /* Not compatible with cmma. */
>> + kvm->arch.has_pfmfi = 0;
>> ret = 0;
>> }
>> mutex_unlock(&kvm->lock);
>> @@ -665,7 +667,7 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
>> if (!sclp.has_cmma)
>> break;
>> ret = -EINVAL;
>> - if (!kvm->arch.use_cmma)
>> + if (!kvm->arch.has_cmma)
>> break;
>>
>> VM_EVENT(kvm, 3, "%s", "RESET: CMMA states");
>> @@ -810,7 +812,7 @@ static int kvm_s390_vm_start_migration(struct kvm *kvm)
>> return -ENOMEM;
>> kvm->arch.migration_state = mgs;
>>
>> - if (kvm->arch.use_cmma) {
>> + if (kvm->arch.has_cmma) {
>> /*
>> * Get the first slot. They are reverse sorted by base_gfn, so
>> * the first slot is also the one at the end of the address
>> @@ -855,7 +857,7 @@ static int kvm_s390_vm_stop_migration(struct kvm *kvm)
>> mgs = kvm->arch.migration_state;
>> kvm->arch.migration_state = NULL;
>>
>> - if (kvm->arch.use_cmma) {
>> + if (kvm->arch.has_cmma) {
>> kvm_s390_sync_request_broadcast(kvm, KVM_REQ_STOP_MIGRATION);
>> /* We have to wait for the essa emulation to finish */
>> synchronize_srcu(&kvm->srcu);
>> @@ -1551,7 +1553,7 @@ static int kvm_s390_get_cmma_bits(struct kvm *kvm,
>> cur = args->start_gfn;
>> i = next = pgstev = 0;
>>
>> - if (unlikely(!kvm->arch.use_cmma))
>> + if (unlikely(!kvm->arch.has_cmma))
>> return -ENXIO;
>> /* Invalid/unsupported flags were specified */
>> if (args->flags & ~KVM_S390_CMMA_PEEK)
>> @@ -1650,7 +1652,7 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm,
>>
>> mask = args->mask;
>>
>> - if (!kvm->arch.use_cmma)
>> + if (!kvm->arch.has_cmma)
>> return -ENXIO;
>> /* invalid/unsupported flags */
>> if (args->flags != 0)
>> @@ -2007,6 +2009,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
>>
>> kvm->arch.css_support = 0;
>> kvm->arch.use_irqchip = 0;
>> + kvm->arch.has_pfmfi = sclp.has_pfmfi;
>> kvm->arch.epoch = 0;
>>
>> spin_lock_init(&kvm->arch.start_stop_lock);
>> @@ -2045,7 +2048,7 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
>> if (kvm_is_ucontrol(vcpu->kvm))
>> gmap_remove(vcpu->arch.gmap);
>>
>> - if (vcpu->kvm->arch.use_cmma)
>> + if (vcpu->kvm->arch.has_cmma)
>> kvm_s390_vcpu_unsetup_cmma(vcpu);
>> free_page((unsigned long)(vcpu->arch.sie_block));
>>
>> @@ -2431,8 +2434,6 @@ int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu)
>> vcpu->arch.sie_block->cbrlo = get_zeroed_page(GFP_KERNEL);
>> if (!vcpu->arch.sie_block->cbrlo)
>> return -ENOMEM;
>> -
>> - vcpu->arch.sie_block->ecb2 &= ~ECB2_PFMFI;
>> return 0;
>> }
>>
>> @@ -2468,7 +2469,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
>> if (test_kvm_facility(vcpu->kvm, 73))
>> vcpu->arch.sie_block->ecb |= ECB_TE;
>>
>> - if (test_kvm_facility(vcpu->kvm, 8) && sclp.has_pfmfi)
>> + if (test_kvm_facility(vcpu->kvm, 8) && vcpu->kvm->arch.has_pfmfi)
>> vcpu->arch.sie_block->ecb2 |= ECB2_PFMFI;
>> if (test_kvm_facility(vcpu->kvm, 130))
>> vcpu->arch.sie_block->ecb2 |= ECB2_IEP;
>> @@ -2502,7 +2503,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
>> else
>> vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
>>
>> - if (vcpu->kvm->arch.use_cmma) {
>> + if (vcpu->kvm->arch.has_cmma) {
>> rc = kvm_s390_vcpu_setup_cmma(vcpu);
>> if (rc)
>> return rc;
>> @@ -3013,7 +3014,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>> * Re-enable CMMA virtualization if CMMA is available and
>> * was used.
>> */
>> - if ((vcpu->kvm->arch.use_cmma) &&
>> + if ((vcpu->kvm->arch.has_cmma) &&
>> (vcpu->kvm->mm->context.use_cmma))
>> vcpu->arch.sie_block->ecb2 |= ECB2_CMMA;
>> goto retry;
>> diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
>> index c4c4e15..908b579 100644
>> --- a/arch/s390/kvm/priv.c
>> +++ b/arch/s390/kvm/priv.c
>> @@ -1050,7 +1050,7 @@ static int handle_essa(struct kvm_vcpu *vcpu)
>> VCPU_EVENT(vcpu, 4, "ESSA: release %d pages", entries);
>> gmap = vcpu->arch.gmap;
>> vcpu->stat.instruction_essa++;
>> - if (!vcpu->kvm->arch.use_cmma)
>> + if (!vcpu->kvm->arch.has_cmma)
>> return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
>>
>> if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
>>
>
>
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