From: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
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 c8c8763..90781ba 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);
}
--
2.5.5
--
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