From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Date: Mon, 1 Nov 2010 09:01:28 +0000 (+0800)
Subject: KVM: avoid unnecessary wait for a async pf
X-Git-Tag: v2.6.38-rc1~244^2~104
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e6d53e3b0db7ae3641f01a2b2af1470fda86d10c;p=pandora-kernel.git

KVM: avoid unnecessary wait for a async pf

In current code, it checks async pf completion out of the wait context,
like this:

if (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
		    !vcpu->arch.apf.halted)
			r = vcpu_enter_guest(vcpu);
		else {
			......
			kvm_vcpu_block(vcpu)
			 ^- waiting until 'async_pf.done' is not empty
}

kvm_check_async_pf_completion(vcpu)
 ^- delete list from async_pf.done

So, if we check aysnc pf completion first, it can be blocked at
kvm_vcpu_block

Fixed by mark the vcpu is unhalted in kvm_check_async_pf_completion()
path

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---

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