Commit 081385db authored by Isaku Yamahata's avatar Isaku Yamahata Committed by Paolo Bonzini
Browse files

KVM: TDX: Handle TDX PV rdmsr/wrmsr hypercall 



Morph PV RDMSR/WRMSR hypercall to EXIT_REASON_MSR_{READ,WRITE} and
wire up KVM backend functions.

For complete_emulated_msr() callback, instead of injecting #GP on error,
implement tdx_complete_emulated_msr() to set return code on error.  Also
set return value on MSR read according to the values from kvm x86
registers.

Suggested-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarIsaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: default avatarBinbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-ID: <20250227012021.1778144-10-binbin.wu@linux.intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent dd50294f

arch/x86/kvm/vmx/main.c

+9 −1
Original line number Diff line number Diff line
@@ -235,6 +235,14 @@ static void vt_msr_filter_changed(struct kvm_vcpu *vcpu) 
	vmx_msr_filter_changed(vcpu);

}



static int vt_complete_emulated_msr(struct kvm_vcpu *vcpu, int err)

{

	if (is_td_vcpu(vcpu))

		return tdx_complete_emulated_msr(vcpu, err);



	return kvm_complete_insn_gp(vcpu, err);

}



#ifdef CONFIG_KVM_SMM

static int vt_smi_allowed(struct kvm_vcpu *vcpu, bool for_injection)

{
@@ -686,7 +694,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = { 
	.migrate_timers = vmx_migrate_timers,



	.msr_filter_changed = vt_msr_filter_changed,

	.complete_emulated_msr = kvm_complete_insn_gp,

	.complete_emulated_msr = vt_complete_emulated_msr,



	.vcpu_deliver_sipi_vector = kvm_vcpu_deliver_sipi_vector,

arch/x86/kvm/vmx/tdx.c

+24 −0
Original line number Diff line number Diff line
@@ -877,6 +877,8 @@ static __always_inline u32 tdcall_to_vmx_exit_reason(struct kvm_vcpu *vcpu) 
	case EXIT_REASON_CPUID:

	case EXIT_REASON_HLT:

	case EXIT_REASON_IO_INSTRUCTION:

	case EXIT_REASON_MSR_READ:

	case EXIT_REASON_MSR_WRITE:

		return tdvmcall_leaf(vcpu);

	case EXIT_REASON_EPT_VIOLATION:

		return EXIT_REASON_EPT_MISCONFIG;
@@ -1906,6 +1908,20 @@ static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu) 
	return ret;

}



int tdx_complete_emulated_msr(struct kvm_vcpu *vcpu, int err)

{

	if (err) {

		tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND);

		return 1;

	}



	if (vmx_get_exit_reason(vcpu).basic == EXIT_REASON_MSR_READ)

		tdvmcall_set_return_val(vcpu, kvm_read_edx_eax(vcpu));



	return 1;

}





int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)

{

	struct vcpu_tdx *tdx = to_tdx(vcpu);
@@ -1971,6 +1987,14 @@ int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath) 
		return tdx_emulate_vmcall(vcpu);

	case EXIT_REASON_IO_INSTRUCTION:

		return tdx_emulate_io(vcpu);

	case EXIT_REASON_MSR_READ:

		kvm_rcx_write(vcpu, tdx->vp_enter_args.r12);

		return kvm_emulate_rdmsr(vcpu);

	case EXIT_REASON_MSR_WRITE:

		kvm_rcx_write(vcpu, tdx->vp_enter_args.r12);

		kvm_rax_write(vcpu, tdx->vp_enter_args.r13 & -1u);

		kvm_rdx_write(vcpu, tdx->vp_enter_args.r13 >> 32);

		return kvm_emulate_wrmsr(vcpu);

	case EXIT_REASON_EPT_MISCONFIG:

		return tdx_emulate_mmio(vcpu);

	case EXIT_REASON_EPT_VIOLATION:

arch/x86/kvm/vmx/tdx.h

+2 −0
Original line number Diff line number Diff line
@@ -173,6 +173,7 @@ static __always_inline void td_##lclass##_clearbit##bits(struct vcpu_tdx *tdx, \ 




bool tdx_interrupt_allowed(struct kvm_vcpu *vcpu);

int tdx_complete_emulated_msr(struct kvm_vcpu *vcpu, int err);



TDX_BUILD_TDVPS_ACCESSORS(16, VMCS, vmcs);

TDX_BUILD_TDVPS_ACCESSORS(32, VMCS, vmcs);
@@ -196,6 +197,7 @@ struct vcpu_tdx { 
};



static inline bool tdx_interrupt_allowed(struct kvm_vcpu *vcpu) { return false; }

static inline int tdx_complete_emulated_msr(struct kvm_vcpu *vcpu, int err) { return 0; }



#endif