[RFC PATCH v5 085/104] KVM: TDX: handle EXIT_REASON_OTHER_SMI

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

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@xxxxxxxxx>
---
 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 946d761adbd3..3d9b4598e166 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 155208a8d768..6fbe89bcfe1e 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1097,6 +1097,13 @@ 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 MSMI.
+		 * #SMI is delivered and handled right after SEAMRET, nothing
+		 * needs to be done in KVM.
+		 */
+		return 1;
 	default:
 		break;
 	}
-- 
2.25.1