From: Wanpeng Li <wanpeng.li@hotmail.com>
Date: Mon, 14 Sep 2015 09:38:51 +0000 (+0800)
Subject: KVM: fix polling for guest halt continued even if disable it
X-Git-Tag: v4.3-rc2~11^2~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=edb9272f35d8bc97c86101a13f67d0ba16f3eecc;p=profile%2Fcommon%2Fplatform%2Fkernel%2Flinux-artik7.git

KVM: fix polling for guest halt continued even if disable it

If there is already some polling ongoing, it's impossible to disable the
polling, since as soon as somebody sets halt_poll_ns to 0, polling will
never stop, as grow and shrink are only handled if halt_poll_ns is != 0.

This patch fix it by reset vcpu->halt_poll_ns in order to stop polling
when polling is disabled.

Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a25a731..eb4c9d2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2043,7 +2043,8 @@ out:
 		else if (vcpu->halt_poll_ns < halt_poll_ns &&
 			block_ns < halt_poll_ns)
 			grow_halt_poll_ns(vcpu);
-	}
+	} else
+		vcpu->halt_poll_ns = 0;
 
 	trace_kvm_vcpu_wakeup(block_ns, waited);
 }