Commit b917ae57 authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger

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: default avatarChristian Borntraeger <borntraeger@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 94a15de8
...@@ -844,6 +844,11 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu, ...@@ -844,6 +844,11 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu,
struct vsie_page *vsie_page) struct vsie_page *vsie_page)
{ {
WRITE_ONCE(vcpu->arch.vsie_block, &vsie_page->scb_s); 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, ...@@ -851,6 +856,7 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu,
*/ */
static void unregister_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); WRITE_ONCE(vcpu->arch.vsie_block, NULL);
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment