[RFC PATCH 57/67] KVM: TDX: Stub in tdx.h with structs, accessors, and VMCS helpers

[isaku.yamahata@intel.com]

From: Sean Christopherson <sean.j.christopherson@intel.com>

Stub in kvm_tdx, vcpu_tdx, their various accessors, and VMCS helpers.
The VMCS helpers, which rely on the stubs, will be used by preparatory
patches to move VMX functions for accessing VMCS state to common code.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/tdx.h | 167 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 167 insertions(+)
 create mode 100644 arch/x86/kvm/vmx/tdx.h

diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
new file mode 100644
index 000000000000..b55108a8e484
--- /dev/null
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -0,0 +1,167 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __KVM_X86_TDX_H
+#define __KVM_X86_TDX_H
+
+#include <linux/list.h>
+#include <linux/kvm_host.h>
+
+#include "tdx_arch.h"
+#include "tdx_errno.h"
+#include "tdx_ops.h"
+
+#ifdef CONFIG_KVM_INTEL_TDX
+
+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[TDX1_NR_TDCX_PAGES];
+};
+
+struct vcpu_tdx {
+	struct kvm_vcpu	vcpu;
+
+	struct tdx_td_page tdvpr;
+	struct tdx_td_page tdvpx[TDX1_NR_TDVPX_PAGES];
+};
+
+static inline bool is_td(struct kvm *kvm)
+{
+	return kvm->arch.vm_type == KVM_X86_TDX_VM;
+}
+
+static inline bool is_td_vcpu(struct kvm_vcpu *vcpu)
+{
+	return is_td(vcpu->kvm);
+}
+
+static inline bool is_debug_td(struct kvm_vcpu *vcpu)
+{
+	return !vcpu->kvm->arch.guest_state_protected;
+}
+
+static inline struct kvm_tdx *to_kvm_tdx(struct kvm *kvm)
+{
+	return container_of(kvm, struct kvm_tdx, kvm);
+}
+
+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_gpr_check(u64 field, u8 bits)
+{
+	BUILD_BUG_ON_MSG(__builtin_constant_p(field) && (field) >= NR_VCPU_REGS,
+			 "Invalid TD guest GPR index");
+}
+
+static __always_inline void tdvps_apic_check(u64 field, u8 bits) {}
+static __always_inline void tdvps_dr_check(u64 field, u8 bits) {}
+static __always_inline void tdvps_state_check(u64 field, u8 bits) {}
+static __always_inline void tdvps_msr_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_ex_ret ex_ret;					       \
+	u64 err;							       \
+									       \
+	tdvps_##lclass##_check(field, bits);				       \
+	err = tdrdvps(tdx->tdvpr.pa, TDVPS_##uclass(field), &ex_ret);	       \
+	if (unlikely(err)) {						       \
+		pr_err("TDRDVPS["#uclass".0x%x] failed: 0x%llx\n", field, err);\
+		return 0;						       \
+	}								       \
+	return (u##bits)ex_ret.r8;					       \
+}									       \
+static __always_inline void td_##lclass##_write##bits(struct vcpu_tdx *tdx,    \
+						      u32 field, u##bits val)  \
+{									       \
+	struct tdx_ex_ret ex_ret;					       \
+	u64 err;							       \
+									       \
+	tdvps_##lclass##_check(field, bits);				       \
+	err = tdwrvps(tdx->tdvpr.pa, TDVPS_##uclass(field), val,	       \
+		      GENMASK_ULL(bits - 1, 0), &ex_ret);		       \
+	if (unlikely(err))						       \
+		pr_err("TDWRVPS["#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_ex_ret ex_ret;					       \
+	u64 err;							       \
+									       \
+	tdvps_##lclass##_check(field, bits);				       \
+	err = tdwrvps(tdx->tdvpr.pa, TDVPS_##uclass(field), bit, bit, &ex_ret);\
+	if (unlikely(err))						       \
+		pr_err("TDWRVPS["#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_ex_ret ex_ret;					       \
+	u64 err;							       \
+									       \
+	tdvps_##lclass##_check(field, bits);				       \
+	err = tdwrvps(tdx->tdvpr.pa, TDVPS_##uclass(field), 0, bit, &ex_ret);  \
+	if (unlikely(err))						       \
+		pr_err("TDWRVPS["#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, APIC, apic);
+TDX_BUILD_TDVPS_ACCESSORS(64, GPR, gpr);
+TDX_BUILD_TDVPS_ACCESSORS(64, DR, dr);
+TDX_BUILD_TDVPS_ACCESSORS(64, STATE, state);
+TDX_BUILD_TDVPS_ACCESSORS(64, MSR, msr);
+TDX_BUILD_TDVPS_ACCESSORS(8, MANAGEMENT, management);
+
+#else
+
+struct kvm_tdx;
+struct vcpu_tdx;
+
+static inline bool is_td(struct kvm *kvm) { return false; }
+static inline bool is_td_vcpu(struct kvm_vcpu *vcpu) { return false; }
+static inline bool is_debug_td(struct kvm_vcpu *vcpu) { return false; }
+static inline struct kvm_tdx *to_kvm_tdx(struct kvm *kvm) { return NULL; }
+static inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu) { return NULL; }
+
+#endif /* CONFIG_KVM_INTEL_TDX */
+
+#endif /* __KVM_X86_TDX_H */
-- 
2.17.1