KVM: s390: Refactor host cmma and pfmfi interpretation controls

use_cmma in kvm_arch means that the KVM hypervisor 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@linux.vnet.ibm.com>
Message-Id: <1518779775-256056-2-git-send-email-frankja@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index afb0f08..27918b1 100644 (file)
--- 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 db35c41..c639c95 100644 (file)
--- 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 (file)
--- 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 56061cf..957be1c 100644 (file)
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -699,6 +699,8 @@ 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);
@@ -1603,7 +1605,7 @@ 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;
        }
@@ -1680,7 +1682,7 @@ 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)
@@ -1730,9 +1732,9 @@ 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:
@@ -2043,6 +2045,7 @@ 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);
@@ -2469,8 +2472,6 @@ 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;
 }
 
@@ -2506,7 +2507,7 @@ 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;
@@ -3038,7 +3039,7 @@ retry:
 
        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.
                 */
@@ -3048,11 +3049,11 @@ retry:
 
        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 f0b4185..ebfa044 100644 (file)
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -1078,9 +1078,9 @@ 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);
                }
                /*