Re: [RFC PATCH v5 096/104] KVM: TDX: Handle TDX PV rdmsr hypercall

From: Paolo Bonzini
Date: Fri Apr 15 2022 - 11:08:31 EST


On 3/4/22 20:49, isaku.yamahata@xxxxxxxxx wrote:
From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

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

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kvm/vmx/tdx.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index cec2660206bd..dd7aaa28bf3a 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1124,6 +1124,23 @@ static int tdx_emulate_mmio(struct kvm_vcpu *vcpu)
return 1;
}
+static int tdx_emulate_rdmsr(struct kvm_vcpu *vcpu)
+{
+ u32 index = tdvmcall_p1_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 handle_tdvmcall(struct kvm_vcpu *vcpu)
{
struct vcpu_tdx *tdx = to_tdx(vcpu);
@@ -1143,6 +1160,8 @@ 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);
default:
break;
}

Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

and feel free to squash with the wrmsr one.

Paolo