From 9a022067ad75b117f1c1e5cbf6a592022cf0a749 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 5 Aug 2014 17:40:47 +0200 Subject: [PATCH] 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 For this reason, the existing function (with an outdated name) is replaced by kvm_s390_vcpu_has_irq() which allows to mask out pending stop irqs.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: Cornelia Huck Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/intercept.c | 4 ++++ arch/s390/kvm/interrupt.c | 4 ++-- arch/s390/kvm/kvm-s390.c | 4 ++-- arch/s390/kvm/kvm-s390.h | 2 +- 4 files changed, 9 insertions(+), 5 deletions(-) diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c index 08e01ac..8976694 100644 --- a/arch/s390/kvm/intercept.c +++ b/arch/s390/kvm/intercept.c @@ -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; diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 1872188..f753c0b 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -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; diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index b987b56..6a5ed33 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -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; diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h index d72ff62..2becffe 100644 --- a/arch/s390/kvm/kvm-s390.h +++ b/arch/s390/kvm/kvm-s390.h @@ -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); -- 2.7.4