Commit 9a022067 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
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KVM: s390: a VCPU may only stop when no interrupts are left pending 



As a SIGP STOP is an interrupt with the least priority, it may only result
in stop of the vcpu when no other interrupts are left pending.

To detect whether a non-stop irq is pending, we need a way to mask out
stop irqs from the general kvm_cpu_has_interrupt() function. For this
reason, the existing function (with an outdated name) is replaced by
kvm_s390_vcpu_has_irq() which allows to mask out pending stop irqs.

Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 6cddd432

arch/s390/kvm/intercept.c

+4 −0
Original line number Diff line number Diff line
@@ -74,6 +74,10 @@ static int handle_stop(struct kvm_vcpu *vcpu) 


	vcpu->stat.exit_stop_request++;



	/* delay the stop if any non-stop irq is pending */

	if (kvm_s390_vcpu_has_irq(vcpu, 1))

		return 0;



	/* avoid races with the injection/SIGP STOP code */

	spin_lock(&li->lock);

	flags = li->irq.stop.flags;

arch/s390/kvm/interrupt.c

+2 −2
Original line number Diff line number Diff line
@@ -749,7 +749,7 @@ int kvm_s390_si_ext_call_pending(struct kvm_vcpu *vcpu) 
	return 0;

}



int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)

int kvm_s390_vcpu_has_irq(struct kvm_vcpu *vcpu, int exclude_stop)

{

	struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int;

	struct kvm_s390_interrupt_info  *inti;
@@ -773,7 +773,7 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) 
	if (!rc && kvm_s390_si_ext_call_pending(vcpu))

		rc = 1;



	if (!rc && kvm_s390_is_stop_irq_pending(vcpu))

	if (!rc && !exclude_stop && kvm_s390_is_stop_irq_pending(vcpu))

		rc = 1;



	return rc;

arch/s390/kvm/kvm-s390.c

+2 −2
Original line number Diff line number Diff line
@@ -806,7 +806,7 @@ out: 


int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)

{

	return kvm_cpu_has_interrupt(vcpu);

	return kvm_s390_vcpu_has_irq(vcpu, 0);

}



void s390_vcpu_block(struct kvm_vcpu *vcpu)
@@ -1241,7 +1241,7 @@ static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu) 
		return 0;

	if (psw_extint_disabled(vcpu))

		return 0;

	if (kvm_cpu_has_interrupt(vcpu))

	if (kvm_s390_vcpu_has_irq(vcpu, 0))

		return 0;

	if (!(vcpu->arch.sie_block->gcr[0] & 0x200ul))

		return 0;

arch/s390/kvm/kvm-s390.h

+1 −1
Original line number Diff line number Diff line
@@ -228,7 +228,7 @@ int s390int_to_s390irq(struct kvm_s390_interrupt *s390int, 
			struct kvm_s390_irq *s390irq);



/* implemented in interrupt.c */

int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);

int kvm_s390_vcpu_has_irq(struct kvm_vcpu *vcpu, int exclude_stop);

int psw_extint_disabled(struct kvm_vcpu *vcpu);

void kvm_s390_destroy_adapters(struct kvm *kvm);

int kvm_s390_si_ext_call_pending(struct kvm_vcpu *vcpu);

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