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authorChristian Borntraeger <borntraeger@de.ibm.com>2014-03-06 16:01:38 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-06 07:59:24 -0700
commit6d807fb1a3280648dffbdb78751d762d07048b5a (patch)
treea1786c627f507f02465d1b41564fb786e1e2a0df
parent0149df238fd66b16e3aab4d1750342a7750150a6 (diff)
KVM: s390: Optimize ucontrol path
commit 2955c83f72801245afd0fe5c560cc75b82bea9aa upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 e0676f390d57..95f4a976c160 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -753,7 +753,8 @@ 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);
}