Messages in this thread Patch in this message | | | From | Wanpeng Li <> | Subject | [PATCH] KVM: X86: Do not yield to self | Date | Thu, 8 Apr 2021 19:23:09 +0800 |
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From: Wanpeng Li <wanpengli@tencent.com>
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@tencent.com> --- Rebased on https://lore.kernel.org/kvm/1617697935-4158-1-git-send-email-wanpengli@tencent.com/
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 43c9f9b..260650f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8230,6 +8230,10 @@ static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id) if (!target) goto no_yield; + /* yield to self */ + if (vcpu->vcpu_id == target->vcpu_id) + goto no_yield; + if (!READ_ONCE(target->ready)) goto no_yield; -- 2.7.4
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