[PATCH v7 094/102] KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall

From: isaku . yamahata
Date: Mon Jun 27 2022 - 18:01:46 EST


From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

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

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/vmx/tdx.c | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 162cab67d1ef..dc66c799cae8 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1170,6 +1170,39 @@ 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_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_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))
@@ -1184,6 +1217,10 @@ 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