From: Wanpeng Li <wanpengli@xxxxxxxxxxx> If the target is self we do not need to yield, we can avoid malicious guest to play this. Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx> --- v1 -> v2: * update comments arch/x86/kvm/x86.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f08e9b4..ce9a1d2 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8231,6 +8231,10 @@ static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id) if (!target || !READ_ONCE(target->ready)) goto no_yield; + /* Ignore requests to yield to self */ + if (vcpu == target) + goto no_yield; + if (kvm_vcpu_yield_to(target) <= 0) goto no_yield; -- 2.7.4
