On 16.02.2018 12:16, 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 cmm has been used before. Let's
> rename the context one to uses_cmm, as the vm does use collaborative
> memory management but the host uses the cmm assist (interpretation
> facility).
>
> Also let's introduce use_pfmfi, so we can remove the pfmfi disablement
> when we activate cmma and rather not activate it in the first place.
>
> Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxxxxxxx>
> ---
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
> arch/s390/include/asm/kvm_host.h | 1 +
> arch/s390/include/asm/mmu.h | 4 ++--
> arch/s390/include/asm/mmu_context.h | 2 +-
> arch/s390/kvm/kvm-s390.c | 23 ++++++++++++-----------
> arch/s390/kvm/priv.c | 4 ++--
> 5 files changed, 18 insertions(+), 16 deletions(-)
>
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index afb0f08..27918b1 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -792,6 +792,7 @@ struct kvm_arch{
> int css_support;
> int use_irqchip;
> int use_cmma;
> + int use_pfmfi;
> int user_cpu_state_ctrl;
> int user_sigp;
> int user_stsi;
> diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h
> index db35c41a..c639c95 100644
> --- a/arch/s390/include/asm/mmu.h
> +++ b/arch/s390/include/asm/mmu.h
> @@ -22,8 +22,8 @@ typedef struct {
> unsigned int has_pgste:1;
> /* The mmu context uses storage keys. */
> unsigned int use_skey:1;
> - /* The mmu context uses CMMA. */
> - unsigned int use_cmma:1;
> + /* The mmu context uses CMM. */
> + unsigned int uses_cmm:1;
> } mm_context_t;
>
> #define INIT_MM_CONTEXT(name) \
> diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
> index 65154ea..d3ebfa8 100644
> --- a/arch/s390/include/asm/mmu_context.h
> +++ b/arch/s390/include/asm/mmu_context.h
> @@ -31,7 +31,7 @@ static inline int init_new_context(struct task_struct *tsk,
> (current->mm && current->mm->context.alloc_pgste);
> mm->context.has_pgste = 0;
> mm->context.use_skey = 0;
> - mm->context.use_cmma = 0;
> + mm->context.uses_cmm = 0;
> #endif
> switch (mm->context.asce_limit) {
> case _REGION2_SIZE:
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 4a2d68c..8fb6549 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -656,6 +656,8 @@ static int kvm_s390_set_mem_control(struct kvm *kvm, struct kvm_device_attr *att
> mutex_lock(&kvm->lock);
> if (!kvm->created_vcpus) {
> kvm->arch.use_cmma = 1;
> + /* Not compatible with cmma. */
> + kvm->arch.use_pfmfi = 0;
> ret = 0;
> }
> mutex_unlock(&kvm->lock);
> @@ -1562,7 +1564,7 @@ static int kvm_s390_get_cmma_bits(struct kvm *kvm,
> return -EINVAL;
> /* CMMA is disabled or was not used, or the buffer has length zero */
> bufsize = min(args->count, KVM_S390_CMMA_SIZE_MAX);
> - if (!bufsize || !kvm->mm->context.use_cmma) {
> + if (!bufsize || !kvm->mm->context.uses_cmm) {
> memset(args, 0, sizeof(*args));
> return 0;
> }
> @@ -1639,7 +1641,7 @@ static int kvm_s390_get_cmma_bits(struct kvm *kvm,
> /*
> * This function sets the CMMA attributes for the given pages. If the input
> * buffer has zero length, no action is taken, otherwise the attributes are
> - * set and the mm->context.use_cmma flag is set.
> + * set and the mm->context.uses_cmm flag is set.
> */
> static int kvm_s390_set_cmma_bits(struct kvm *kvm,
> const struct kvm_s390_cmma_log *args)
> @@ -1689,9 +1691,9 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm,
> srcu_read_unlock(&kvm->srcu, srcu_idx);
> up_read(&kvm->mm->mmap_sem);
>
> - if (!kvm->mm->context.use_cmma) {
> + if (!kvm->mm->context.uses_cmm) {
> down_write(&kvm->mm->mmap_sem);
> - kvm->mm->context.use_cmma = 1;
> + kvm->mm->context.uses_cmm = 1;
> up_write(&kvm->mm->mmap_sem);
> }
> out:
> @@ -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.use_pfmfi = sclp.has_pfmfi;
> kvm->arch.epoch = 0;
>
> spin_lock_init(&kvm->arch.start_stop_lock);
> @@ -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.use_pfmfi)
> vcpu->arch.sie_block->ecb2 |= ECB2_PFMFI;
> if (test_kvm_facility(vcpu->kvm, 130))
> vcpu->arch.sie_block->ecb2 |= ECB2_IEP;
> @@ -3000,7 +3001,7 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>
> if (kvm_check_request(KVM_REQ_START_MIGRATION, vcpu)) {
> /*
> - * Disable CMMA virtualization; we will emulate the ESSA
> + * Disable CMM virtualization; we will emulate the ESSA
> * instruction manually, in order to provide additional
> * functionalities needed for live migration.
> */
> @@ -3010,11 +3011,11 @@ static int kvm_s390_handle_requests(struct kvm_vcpu *vcpu)
>
> if (kvm_check_request(KVM_REQ_STOP_MIGRATION, vcpu)) {
> /*
> - * Re-enable CMMA virtualization if CMMA is available and
> - * was used.
> + * Re-enable CMM virtualization if CMMA is available and
> + * CMM has been used.
> */
> if ((vcpu->kvm->arch.use_cmma) &&
> - (vcpu->kvm->mm->context.use_cmma))
> + (vcpu->kvm->mm->context.uses_cmm))
> 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..76a2380 100644
> --- a/arch/s390/kvm/priv.c
> +++ b/arch/s390/kvm/priv.c
> @@ -1072,9 +1072,9 @@ static int handle_essa(struct kvm_vcpu *vcpu)
> * value really needs to be written to; if the value is
> * already correct, we do nothing and avoid the lock.
> */
> - if (vcpu->kvm->mm->context.use_cmma == 0) {
> + if (vcpu->kvm->mm->context.uses_cmm == 0) {
> down_write(&vcpu->kvm->mm->mmap_sem);
> - vcpu->kvm->mm->context.use_cmma = 1;
> + vcpu->kvm->mm->context.uses_cmm = 1;
> up_write(&vcpu->kvm->mm->mmap_sem);
> }
> /*
>
--
Thanks,
David / dhildenb
