Commit c9f0a2b8 authored by Janosch Frank's avatar Janosch Frank Committed by Christian Borntraeger
Browse files

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: default avatarJanosch Frank <frankja@linux.vnet.ibm.com>
Message-Id: <1518779775-256056-2-git-send-email-frankja@linux.vnet.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent c3b9e3e1

arch/s390/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

arch/s390/include/asm/mmu.h

+2 −2
Original line number Diff line number Diff line
@@ -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)						   \

arch/s390/include/asm/mmu_context.h

+1 −1
Original line number Diff line number Diff line
@@ -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:

arch/s390/kvm/kvm-s390.c

+12 −11
Original line number Diff line number Diff line
@@ -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;

	}

arch/s390/kvm/priv.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

		}

		/*

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