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authorDavid Hildenbrand <dahi@linux.vnet.ibm.com>2015-07-07 21:39:35 +0300
committerChristian Borntraeger <borntraeger@de.ibm.com>2016-06-21 10:43:46 +0300
commitb917ae573f5b3f7fee8cfb0d42d74bd8641f6401 (patch)
treef582eb7dc28567929d6a54185a53fac1036341bf /arch/s390/kvm
parent94a15de8fb2667791d66c49610676ea2add90034 (diff)
downloadlinux-b917ae573f5b3f7fee8cfb0d42d74bd8641f6401.tar.xz
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 <borntraeger@de.ibm.com> Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kvm')
-rw-r--r--arch/s390/kvm/vsie.c6
1 files changed, 6 insertions, 0 deletions
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);
}