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>
Subject: [PATCH v12 089/106] KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall
Date:   Mon, 27 Feb 2023 00:23:28 -0800
Message-Id: <9ed1d1be8ebb41c72f9077134dee9107a596a5fa.1677484918.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

Wire up TDX PV rdmsr/wrmsr hypercall to the KVM backend function.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/vmx/tdx.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 4455bf5ae1ac..f4c0f715a36f 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1190,6 +1190,41 @@ static int tdx_emulate_mmio(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
+static int tdx_emulate_rdmsr(struct kvm_vcpu *vcpu)
+{
+	u32 index = tdvmcall_a0_read(vcpu);
+	u64 data;
+
+	if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_READ) ||
+	    kvm_get_msr(vcpu, index, &data)) {
+		trace_kvm_msr_read_ex(index);
+		tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND);
+		return 1;
+	}
+	trace_kvm_msr_read(index, data);
+
+	tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS);
+	tdvmcall_set_return_val(vcpu, data);
+	return 1;
+}
+
+static int tdx_emulate_wrmsr(struct kvm_vcpu *vcpu)
+{
+	u32 index = tdvmcall_a0_read(vcpu);
+	u64 data = tdvmcall_a1_read(vcpu);
+
+	if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_WRITE) ||
+	    kvm_set_msr(vcpu, index, data)) {
+		trace_kvm_msr_write_ex(index, data);
+		tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND);
+		return 1;
+	}
+
+	trace_kvm_msr_write(index, data);
+	tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS);
+	return 1;
+}
+
 static int handle_tdvmcall(struct kvm_vcpu *vcpu)
 {
 	if (tdvmcall_exit_type(vcpu))
@@ -1204,6 +1239,10 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu)
 		return tdx_emulate_io(vcpu);
 	case EXIT_REASON_EPT_VIOLATION:
 		return tdx_emulate_mmio(vcpu);
+	case EXIT_REASON_MSR_READ:
+		return tdx_emulate_rdmsr(vcpu);
+	case EXIT_REASON_MSR_WRITE:
+		return tdx_emulate_wrmsr(vcpu);
 	default:
 		break;
 	}
-- 
2.25.1