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authorChristian Borntraeger <borntraeger@de.ibm.com>2014-03-06 16:01:38 +0100
committerChristian Borntraeger <borntraeger@de.ibm.com>2014-03-17 11:06:51 +0100
commit2955c83f72801245afd0fe5c560cc75b82bea9aa (patch)
treedfb63b55c26af70604c8f175a8c11af557906ac4 /arch/s390/kvm
parentfed495d25e0137028c37678a14cd1d8466c02dd3 (diff)
downloadop-kernel-dev-2955c83f72801245afd0fe5c560cc75b82bea9aa.zip
op-kernel-dev-2955c83f72801245afd0fe5c560cc75b82bea9aa.tar.gz
KVM: s390: Optimize ucontrol path
Since commit 7c470539c95630c1f2a10f109e96f249730b75eb (s390/kvm: avoid automatic sie reentry) we will run through the C code of KVM on host interrupts instead of just reentering the guest. This will result in additional ucontrol exits (at least HZ per second). Let handle a 0 intercept in the kernel and dont return to userspace, even if in ucontrol mode. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> CC: stable@vger.kernel.org
Diffstat (limited to 'arch/s390/kvm')
-rw-r--r--arch/s390/kvm/kvm-s390.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6268357..7337c57 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -896,7 +896,8 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
if (rc == 0) {
if (kvm_is_ucontrol(vcpu->kvm))
- rc = -EOPNOTSUPP;
+ /* Don't exit for host interrupts. */
+ rc = vcpu->arch.sie_block->icptcode ? -EOPNOTSUPP : 0;
else
rc = kvm_handle_sie_intercept(vcpu);
}
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