Unverified Commit fd198cd1 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
Browse files

!9975 KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() 

Merge Pull Request from: @ci-robot 
 
PR sync from: felix <fuzhen5@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/4225UWLBTXUQTAFGL7CNZ3V4HYIJ6Z5V/ 
 
https://gitee.com/src-openeuler/kernel/issues/IACT6J 
 
Link:https://gitee.com/openeuler/kernel/pulls/9975

 

Reviewed-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parents 4c400614 35c56f5a

virt/kvm/kvm_main.c

+3 −2
Original line number Diff line number Diff line
@@ -3046,12 +3046,13 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) 
{

	struct kvm *kvm = me->kvm;

	struct kvm_vcpu *vcpu;

	int last_boosted_vcpu = me->kvm->last_boosted_vcpu;

	int last_boosted_vcpu;

	int yielded = 0;

	int try = 3;

	int pass;

	int i;



	last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu);

	kvm_vcpu_set_in_spin_loop(me, true);

	/*

	 * We boost the priority of a VCPU that is runnable but not
@@ -3082,7 +3083,7 @@ void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) 


			yielded = kvm_vcpu_yield_to(vcpu);

			if (yielded > 0) {

				kvm->last_boosted_vcpu = i;

				WRITE_ONCE(kvm->last_boosted_vcpu, i);

				break;

			} else if (yielded < 0) {

				try--;