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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>
Subject: [RFC PATCH v6 096/104] KVM: TDX: Handle TDX PV report fatal error hypercall
Date:   Thu,  5 May 2022 11:15:30 -0700
Message-Id: <6bb829189d8d94c64fb42db2d84f7519b7d29359.1651774251.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

Wire up TDX PV report fatal error hypercall to KVM_SYSTEM_EVENT_CRASH KVM
exit event.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/vmx/tdx.c   | 21 +++++++++++++++++++++
 include/uapi/linux/kvm.h |  1 +
 2 files changed, 22 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 1518a8c310d6..ee83539d5228 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1202,6 +1202,25 @@ static int tdx_emulate_wrmsr(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+static int tdx_report_fatal_error(struct kvm_vcpu *vcpu)
+{
+	/*
+	 * Exit to userspace device model for teardown.
+	 * Because guest TD is already panicing, returning an error to guerst TD
+	 * doesn't make sense.  No argument check is done.
+	 */
+
+	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+	vcpu->run->system_event.type =
+		KVM_SYSTEM_EVENT_TDX | KVM_SYSTEM_EVENT_NDATA_VALID;
+	vcpu->run->system_event.ndata = 3;
+	vcpu->run->system_event.data[0] = TDG_VP_VMCALL_REPORT_FATAL_ERROR;
+	vcpu->run->system_event.data[1] = tdvmcall_a0_read(vcpu);
+	vcpu->run->system_event.data[2] = tdvmcall_a1_read(vcpu);
+
+	return 0;
+}
+
 static int handle_tdvmcall(struct kvm_vcpu *vcpu)
 {
 	if (tdvmcall_exit_type(vcpu))
@@ -1220,6 +1239,8 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu)
 		return tdx_emulate_rdmsr(vcpu);
 	case EXIT_REASON_MSR_WRITE:
 		return tdx_emulate_wrmsr(vcpu);
+	case TDG_VP_VMCALL_REPORT_FATAL_ERROR:
+		return tdx_report_fatal_error(vcpu);
 	default:
 		break;
 	}
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9a3fd7b41fc5..df1b89ffdac6 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -445,6 +445,7 @@ struct kvm_run {
 #define KVM_SYSTEM_EVENT_RESET          2
 #define KVM_SYSTEM_EVENT_CRASH          3
 #define KVM_SYSTEM_EVENT_SEV_TERM       4
+#define KVM_SYSTEM_EVENT_TDX            5
 #define KVM_SYSTEM_EVENT_NDATA_VALID    (1u << 31)
 			__u32 type;
 			__u32 ndata;
-- 
2.25.1