KVM: s390: vsie: simulate VCPU SIE entry/exit

VCPU requests and VCPU blocking right now don't take care of the vSIE
(as it was not necessary until now). But we want to have synchronous VCPU
requests that will also be handled before running the vSIE again.

So let's simulate a SIE entry of the VCPU when calling the sie during
vSIE handling and check for PROG_ flags. The existing infrastructure
(e.g. exit_sie()) will then detect that the SIE (in form of the vSIE) is
running and properly kick the vSIE CPU, resulting in it leaving the vSIE
loop and therefore the vSIE interception handler, allowing it to handle
VCPU requests.

E.g. if we want to modify the crycb of the VCPU and make sure that any
masks also get applied to the VSIE crycb shadow (which uses masks from the
VCPU crycb), we will need a way to hinder the vSIE from running and make
sure to process the updated crycb before reentering the vSIE again.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Message-Id: <20180925231641.4954-2-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 981e3ba97461..1f6e36cdce0d 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -290,6 +290,7 @@ void kvm_s390_vcpu_start(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_stop(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_block(struct kvm_vcpu *vcpu);
 void kvm_s390_vcpu_unblock(struct kvm_vcpu *vcpu);
+bool kvm_s390_vcpu_sie_inhibited(struct kvm_vcpu *vcpu);
 void exit_sie(struct kvm_vcpu *vcpu);
 void kvm_s390_sync_request(int req, struct kvm_vcpu *vcpu);
 int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu);