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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>, erdemaktas@google.com,
        Sean Christopherson <seanjc@google.com>,
        Sagi Shahar <sagis@google.com>,
        David Matlack <dmatlack@google.com>,
        Kai Huang <kai.huang@intel.com>,
        Zhi Wang <zhi.wang.linux@gmail.com>, chen.bo@intel.com,
        hang.yuan@intel.com, tina.zhang@intel.com
Subject: [PATCH v16 084/116] KVM: TDX: handle EXIT_REASON_OTHER_SMI
Date:   Mon, 16 Oct 2023 09:14:36 -0700
Message-Id: <31a43bf32cb48b408ed447e93b06e2480ca9ab85.1697471314.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

If the control reaches EXIT_REASON_OTHER_SMI, #SMI is delivered and
handled right after returning from the TDX module to KVM nothing needs to
be done in KVM.  Continue TDX vcpu execution.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/include/uapi/asm/vmx.h | 1 +
 arch/x86/kvm/vmx/tdx.c          | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/include/uapi/asm/vmx.h b/arch/x86/include/uapi/asm/vmx.h
index a5faf6d88f1b..b3a30ef3efdd 100644
--- a/arch/x86/include/uapi/asm/vmx.h
+++ b/arch/x86/include/uapi/asm/vmx.h
@@ -34,6 +34,7 @@
 #define EXIT_REASON_TRIPLE_FAULT        2
 #define EXIT_REASON_INIT_SIGNAL			3
 #define EXIT_REASON_SIPI_SIGNAL         4
+#define EXIT_REASON_OTHER_SMI           6
 
 #define EXIT_REASON_INTERRUPT_WINDOW    7
 #define EXIT_REASON_NMI_WINDOW          8
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 306d555dda35..618c2ecec26a 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1339,6 +1339,13 @@ int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
 	WARN_ON_ONCE(fastpath != EXIT_FASTPATH_NONE);
 
 	switch (exit_reason.basic) {
+	case EXIT_REASON_OTHER_SMI:
+		/*
+		 * If reach here, it's not a Machine Check System Management
+		 * Interrupt(MSMI).  #SMI is delivered and handled right after
+		 * SEAMRET, nothing needs to be done in KVM.
+		 */
+		return 1;
 	default:
 		break;
 	}
-- 
2.25.1