Commit a1fa4cbd authored by Wanpeng Li's avatar Wanpeng Li Committed by Paolo Bonzini
Browse files

KVM: X86: Do not yield to self 



If the target is self we do not need to yield, we can avoid malicious
guest to play this.

Signed-off-by: default avatarWanpeng Li <wanpengli@tencent.com>
Message-Id: <1617941911-5338-3-git-send-email-wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 4a7132ef

arch/x86/kvm/x86.c

+4 −0
Original line number Diff line number Diff line
@@ -8228,6 +8228,10 @@ 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;