[RFC PATCH v3 49/59] KVM: VMX: Add macro framework to read/write VMCS for VMs and TDs

[isaku . yamahata]

From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

Add a macro framework to hide VMX vs. TDX details of VMREAD and VMWRITE
so the VMX and TDX can shared common flows, e.g. accessing DTs.

Note, the TDX paths are dead code at this time.  There is no great way
to deal with the chicken-and-egg scenario of having things in place for
TDX without first having TDX.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 arch/x86/kvm/vmx/common.h | 41 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/x86/kvm/vmx/common.h b/arch/x86/kvm/vmx/common.h
index 9e5865b05d47..d37ef4dd9d90 100644
--- a/arch/x86/kvm/vmx/common.h
+++ b/arch/x86/kvm/vmx/common.h
@@ -11,6 +11,47 @@
 #include "vmcs.h"
 #include "vmx.h"
 #include "x86.h"
+#include "tdx.h"
+
+#ifdef CONFIG_INTEL_TDX_HOST
+#define VT_BUILD_VMCS_HELPERS(type, bits, tdbits)			   \
+static __always_inline type vmread##bits(struct kvm_vcpu *vcpu,		   \
+					 unsigned long field)		   \
+{									   \
+	if (unlikely(is_td_vcpu(vcpu))) {				   \
+		if (KVM_BUG_ON(!is_debug_td(vcpu), vcpu->kvm))		   \
+			return 0;					   \
+		return td_vmcs_read##tdbits(to_tdx(vcpu), field);	   \
+	}								   \
+	return vmcs_read##bits(field);					   \
+}									   \
+static __always_inline void vmwrite##bits(struct kvm_vcpu *vcpu,	   \
+					  unsigned long field, type value) \
+{									   \
+	if (unlikely(is_td_vcpu(vcpu))) {				   \
+		if (KVM_BUG_ON(!is_debug_td(vcpu), vcpu->kvm))		   \
+			return;						   \
+		return td_vmcs_write##tdbits(to_tdx(vcpu), field, value);  \
+	}								   \
+	vmcs_write##bits(field, value);					   \
+}
+#else
+#define VT_BUILD_VMCS_HELPERS(type, bits, tdbits)			   \
+static __always_inline type vmread##bits(struct kvm_vcpu *vcpu,		   \
+					 unsigned long field)		   \
+{									   \
+	return vmcs_read##bits(field);					   \
+}									   \
+static __always_inline void vmwrite##bits(struct kvm_vcpu *vcpu,	   \
+					  unsigned long field, type value) \
+{									   \
+	vmcs_write##bits(field, value);					   \
+}
+#endif /* CONFIG_INTEL_TDX_HOST */
+VT_BUILD_VMCS_HELPERS(u16, 16, 16);
+VT_BUILD_VMCS_HELPERS(u32, 32, 32);
+VT_BUILD_VMCS_HELPERS(u64, 64, 64);
+VT_BUILD_VMCS_HELPERS(unsigned long, l, 64);
 
 extern unsigned long vmx_host_idt_base;
 void vmx_do_interrupt_nmi_irqoff(unsigned long entry);
-- 
2.25.1