Received-SPF: Pass (protection.outlook.com: domain of amd.com designates
 165.204.84.17 as permitted sender) receiver=protection.outlook.com;
 client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; pr=C
From:   Santosh Shukla <santosh.shukla@amd.com>
To:     <kvm@vger.kernel.org>, <seanjc@google.com>
CC:     <pbonzini@redhat.com>, <jmattson@google.com>, <joro@8bytes.org>,
        <linux-kernel@vger.kernel.org>, <mail@maciej.szmigiero.name>,
        <mlevitsk@redhat.com>, <thomas.lendacky@amd.com>,
        <vkuznets@redhat.com>
Subject: [PATCHv3 03/10] KVM: SVM: add wrappers to enable/disable IRET interception
Date:   Mon, 27 Feb 2023 09:23:53 +0530
Message-ID: <20230227035400.1498-4-santosh.shukla@amd.com>
In-Reply-To: <20230227035400.1498-1-santosh.shukla@amd.com>
References: <20230227035400.1498-1-santosh.shukla@amd.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Feb 2023 03:55:11.0769
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 049472ba-e4dc-4d40-2337-08db18766cad
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com]
X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT031.eop-nam11.prod.protection.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4107
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Maxim Levitsky <mlevitsk@redhat.com>

SEV-ES guests don't use IRET interception for the detection of
an end of a NMI.

Therefore it makes sense to create a wrapper to avoid repeating
the check for the SEV-ES.

No functional change is intended.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
[Renamed iret intercept API of style svm_{clr,set}_iret_intercept()]
Signed-off-by: Santosh Shukla <Santosh.Shukla@amd.com>
---
v3:
Reworded commit description per Sean's v2 comment:
https://lore.kernel.org/all/Y9RypRsfpLteK51v@google.com/

 arch/x86/kvm/svm/svm.c | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index cf6ae093ed19..da936723e8ca 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2490,16 +2490,29 @@ static int task_switch_interception(struct kvm_vcpu *vcpu)
 			       has_error_code, error_code);
 }
 
+static void svm_clr_iret_intercept(struct vcpu_svm *svm)
+{
+	if (!sev_es_guest(svm->vcpu.kvm))
+		svm_clr_intercept(svm, INTERCEPT_IRET);
+}
+
+static void svm_set_iret_intercept(struct vcpu_svm *svm)
+{
+	if (!sev_es_guest(svm->vcpu.kvm))
+		svm_set_intercept(svm, INTERCEPT_IRET);
+}
+
 static int iret_interception(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 
 	++vcpu->stat.nmi_window_exits;
 	svm->awaiting_iret_completion = true;
-	if (!sev_es_guest(vcpu->kvm)) {
-		svm_clr_intercept(svm, INTERCEPT_IRET);
+
+	svm_clr_iret_intercept(svm);
+	if (!sev_es_guest(vcpu->kvm))
 		svm->nmi_iret_rip = kvm_rip_read(vcpu);
-	}
+
 	kvm_make_request(KVM_REQ_EVENT, vcpu);
 	return 1;
 }
@@ -3491,8 +3504,7 @@ static void svm_inject_nmi(struct kvm_vcpu *vcpu)
 		return;
 
 	svm->nmi_masked = true;
-	if (!sev_es_guest(vcpu->kvm))
-		svm_set_intercept(svm, INTERCEPT_IRET);
+	svm_set_iret_intercept(svm);
 	++vcpu->stat.nmi_injections;
 }
 
@@ -3632,12 +3644,10 @@ static void svm_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
 
 	if (masked) {
 		svm->nmi_masked = true;
-		if (!sev_es_guest(vcpu->kvm))
-			svm_set_intercept(svm, INTERCEPT_IRET);
+		svm_set_iret_intercept(svm);
 	} else {
 		svm->nmi_masked = false;
-		if (!sev_es_guest(vcpu->kvm))
-			svm_clr_intercept(svm, INTERCEPT_IRET);
+		svm_clr_iret_intercept(svm);
 	}
 }
 
-- 
2.25.1