[RFC PATCH v5 019/104] KVM: TDX: Stub in tdx.h with structs, accessors, and VMCS helpers

[isaku . yamahata]

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

Stub in kvm_tdx, vcpu_tdx, and their various accessors.  TDX defines
SEAMCALL APIs to access TDX control structures corresponding to the VMX
VMCS.  Introduce helper accessors to hide its SEAMCALL ABI details.

Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 arch/x86/kvm/vmx/tdx.h | 101 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 101 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 616fbf79b129..e4bb8831764e 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -3,14 +3,29 @@
 #define __KVM_X86_TDX_H
 
 #ifdef CONFIG_INTEL_TDX_HOST
+
+#include "tdx_ops.h"
+
 int tdx_module_setup(void);
 
+struct tdx_td_page {
+	unsigned long va;
+	hpa_t pa;
+	bool added;
+};
+
 struct kvm_tdx {
 	struct kvm kvm;
+
+	struct tdx_td_page tdr;
+	struct tdx_td_page *tdcs;
 };
 
 struct vcpu_tdx {
 	struct kvm_vcpu	vcpu;
+
+	struct tdx_td_page tdvpr;
+	struct tdx_td_page *tdvpx;
 };
 
 static inline bool is_td(struct kvm *kvm)
@@ -32,6 +47,92 @@ static inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu)
 {
 	return container_of(vcpu, struct vcpu_tdx, vcpu);
 }
+
+static __always_inline void tdvps_vmcs_check(u32 field, u8 bits)
+{
+	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && (field) & 0x1,
+			 "Read/Write to TD VMCS *_HIGH fields not supported");
+
+	BUILD_BUG_ON(bits != 16 && bits != 32 && bits != 64);
+
+	BUILD_BUG_ON_MSG(bits != 64 && __builtin_constant_p(field) &&
+			 (((field) & 0x6000) == 0x2000 ||
+			  ((field) & 0x6000) == 0x6000),
+			 "Invalid TD VMCS access for 64-bit field");
+	BUILD_BUG_ON_MSG(bits != 32 && __builtin_constant_p(field) &&
+			 ((field) & 0x6000) == 0x4000,
+			 "Invalid TD VMCS access for 32-bit field");
+	BUILD_BUG_ON_MSG(bits != 16 && __builtin_constant_p(field) &&
+			 ((field) & 0x6000) == 0x0000,
+			 "Invalid TD VMCS access for 16-bit field");
+}
+
+static __always_inline void tdvps_state_non_arch_check(u64 field, u8 bits) {}
+static __always_inline void tdvps_management_check(u64 field, u8 bits) {}
+
+#define TDX_BUILD_TDVPS_ACCESSORS(bits, uclass, lclass)				\
+static __always_inline u##bits td_##lclass##_read##bits(struct vcpu_tdx *tdx,	\
+							u32 field)		\
+{										\
+	struct tdx_module_output out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_rd(tdx->tdvpr.pa, TDVPS_##uclass(field), &out);		\
+	if (unlikely(err)) {							\
+		pr_err("TDH_VP_RD["#uclass".0x%x] failed: 0x%llx\n",		\
+		       field, err);						\
+		return 0;							\
+	}									\
+	return (u##bits)out.r8;							\
+}										\
+static __always_inline void td_##lclass##_write##bits(struct vcpu_tdx *tdx,	\
+						      u32 field, u##bits val)	\
+{										\
+	struct tdx_module_output out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(tdx->tdvpr.pa, TDVPS_##uclass(field), val,		\
+		      GENMASK_ULL(bits - 1, 0), &out);				\
+	if (unlikely(err))							\
+		pr_err("TDH_VP_WR["#uclass".0x%x] = 0x%llx failed: 0x%llx\n",	\
+		       field, (u64)val, err);					\
+}										\
+static __always_inline void td_##lclass##_setbit##bits(struct vcpu_tdx *tdx,	\
+						       u32 field, u64 bit)	\
+{										\
+	struct tdx_module_output out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(tdx->tdvpr.pa, TDVPS_##uclass(field), bit, bit,		\
+			&out);							\
+	if (unlikely(err))							\
+		pr_err("TDH_VP_WR["#uclass".0x%x] |= 0x%llx failed: 0x%llx\n",	\
+		       field, bit, err);					\
+}										\
+static __always_inline void td_##lclass##_clearbit##bits(struct vcpu_tdx *tdx,	\
+							 u32 field, u64 bit)	\
+{										\
+	struct tdx_module_output out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(tdx->tdvpr.pa, TDVPS_##uclass(field), 0, bit,		\
+			&out);							\
+	if (unlikely(err))							\
+		pr_err("TDH_VP_WR["#uclass".0x%x] &= ~0x%llx failed: 0x%llx\n",	\
+		       field, bit,  err);					\
+}
+
+TDX_BUILD_TDVPS_ACCESSORS(16, VMCS, vmcs);
+TDX_BUILD_TDVPS_ACCESSORS(32, VMCS, vmcs);
+TDX_BUILD_TDVPS_ACCESSORS(64, VMCS, vmcs);
+
+TDX_BUILD_TDVPS_ACCESSORS(64, STATE_NON_ARCH, state_non_arch);
+TDX_BUILD_TDVPS_ACCESSORS(8, MANAGEMENT, management);
+
 #else
 static inline int tdx_module_setup(void) { return -ENODEV; };
 
-- 
2.25.1