From mboxrd@z Thu Jan 1 00:00:00 1970 From: Liran Alon Subject: [PATCH v2 4/8] KVM: x86: Warn if userspace overrides existing injected exception/interrupt Date: Tue, 21 Nov 2017 17:30:07 +0200 Message-ID: <1511278211-12257-5-git-send-email-liran.alon@oracle.com> References: <1511278211-12257-1-git-send-email-liran.alon@oracle.com> Cc: jmattson@google.com, wanpeng.li@hotmail.com, idan.brown@oracle.com, Liran Alon , Krish Sadhukhan To: pbonzini@redhat.com, rkrcmar@redhat.com, kvm@vger.kernel.org Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:29310 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750772AbdKUPbL (ORCPT ); Tue, 21 Nov 2017 10:31:11 -0500 In-Reply-To: <1511278211-12257-1-git-send-email-liran.alon@oracle.com> Sender: kvm-owner@vger.kernel.org List-ID: An alternative could have been done to return -EBUSY in this case. For now, we decided to just silently override exception and warn on such an attempt. Signed-off-by: Liran Alon Reviewed-by: Nikita Leshenko Reviewed-by: Krish Sadhukhan Signed-off-by: Krish Sadhukhan --- arch/x86/kvm/x86.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1490da89de4b..c8cec7c39c1c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3153,12 +3153,25 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu, return -EINVAL; process_nmi(vcpu); + + /* + * Warn if userspace is overriding existing + * injected exception + */ + WARN_ON_ONCE(vcpu->arch.exception.injected && + events->exception.injected); vcpu->arch.exception.injected = events->exception.injected; vcpu->arch.exception.pending = false; vcpu->arch.exception.nr = events->exception.nr; vcpu->arch.exception.has_error_code = events->exception.has_error_code; vcpu->arch.exception.error_code = events->exception.error_code; + /* + * Warn if userspace is overriding existing + * injected interrupt + */ + WARN_ON_ONCE(vcpu->arch.interrupt.injected && + events->interrupt.injected); vcpu->arch.interrupt.injected = events->interrupt.injected; vcpu->arch.interrupt.nr = events->interrupt.nr; vcpu->arch.interrupt.soft = events->interrupt.soft; -- 1.9.1