From b917ae573f5b3f7fee8cfb0d42d74bd8641f6401 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 7 Jul 2015 20:39:35 +0200 Subject: [PATCH] KVM: s390: vsie: speed up VCPU external calls Whenever a SIGP external call is injected via the SIGP external call interpretation facility, the VCPU is not kicked. When a VCPU is currently in the VSIE, the external call might not be processed immediately. Therefore we have to provoke partial execution exceptions, which leads to a kick of the VCPU and therefore also kick out of VSIE. This is done by simulating the WAIT state. This bit has no other side effects. Acked-by: Christian Borntraeger Signed-off-by: David Hildenbrand Signed-off-by: Christian Borntraeger --- arch/s390/kvm/vsie.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c index c8c8763e7822..90781ba52803 100644 --- a/arch/s390/kvm/vsie.c +++ b/arch/s390/kvm/vsie.c @@ -844,6 +844,11 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page) { WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); + /* + * External calls have to lead to a kick of the vcpu and + * therefore the vsie -> Simulate Wait state. + */ + atomic_or(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags); } /* @@ -851,6 +856,7 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu, */ static void unregister_shadow_scb(struct kvm_vcpu *vcpu) { + atomic_andnot(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags); WRITE_ONCE(vcpu->arch.vsie_block, NULL); } -- 2.39.5