linux-kernel - [PATCH 4/7] KVM: SVM: Report NMI not allowed when Guest busy handling VNMI

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 2 Jun 2022 19:56:17 +0530
From:   Santosh Shukla <santosh.shukla@....com>
To:     Paolo Bonzini <pbonzini@...hat.com>
CC:     Sean Christopherson <seanjc@...gle.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>,
        Tom Lendacky <thomas.lendacky@....com>, <kvm@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <Santosh.Shukla@....com>
Subject: [PATCH 4/7] KVM: SVM: Report NMI not allowed when Guest busy handling VNMI

In the VNMI case, Report NMI is not allowed when the processor set the
V_NMI_MASK to 1 which means the Guest is busy handling VNMI.

Signed-off-by: Santosh Shukla <santosh.shukla@....com>
---
 arch/x86/kvm/svm/svm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index d67a54517d95..a405e414cae4 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3483,6 +3483,9 @@ bool svm_nmi_blocked(struct kvm_vcpu *vcpu)
 	struct vmcb *vmcb = svm->vmcb;
 	bool ret;
 
+	if (is_vnmi_enabled(vmcb) && is_vnmi_mask_set(vmcb))
+		return true;
+
 	if (!gif_set(svm))
 		return true;
 
@@ -3618,6 +3621,9 @@ static void svm_enable_nmi_window(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
+	if (is_vnmi_enabled(svm->vmcb) && is_vnmi_mask_set(svm->vmcb))
+		return;
+
 	if ((vcpu->arch.hflags & (HF_NMI_MASK | HF_IRET_MASK)) == HF_NMI_MASK)
 		return; /* IRET will cause a vm exit */
 
-- 
2.25.1