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From:   isaku.yamahata@intel.com
To:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     isaku.yamahata@intel.com, isaku.yamahata@gmail.com,
        Paolo Bonzini <pbonzini@redhat.com>, erdemaktas@google.com,
        Sean Christopherson <seanjc@google.com>,
        Sagi Shahar <sagis@google.com>,
        David Matlack <dmatlack@google.com>,
        Kai Huang <kai.huang@intel.com>,
        Zhi Wang <zhi.wang.linux@gmail.com>, chen.bo@intel.com,
        hang.yuan@intel.com, tina.zhang@intel.com
Subject: [PATCH v16 051/116] KVM: TDX: Add accessors VMX VMCS helpers
Date:   Mon, 16 Oct 2023 09:14:03 -0700
Message-Id: <93a62133f20b0a4b450b6a4389ae2e6e4991ca1f.1697471314.git.isaku.yamahata@intel.com>
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From: Isaku Yamahata <isaku.yamahata@intel.com>

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: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/vmx/tdx.h | 95 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 961a7da2452a..d92a75c78e6e 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -57,6 +57,101 @@ 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)
+{
+#define VMCS_ENC_ACCESS_TYPE_MASK	0x1UL
+#define VMCS_ENC_ACCESS_TYPE_FULL	0x0UL
+#define VMCS_ENC_ACCESS_TYPE_HIGH	0x1UL
+#define VMCS_ENC_ACCESS_TYPE(field)	((field) & VMCS_ENC_ACCESS_TYPE_MASK)
+
+	/* TDX is 64bit only.  HIGH field isn't supported. */
+	BUILD_BUG_ON_MSG(__builtin_constant_p(field) &&
+			 VMCS_ENC_ACCESS_TYPE(field) == VMCS_ENC_ACCESS_TYPE_HIGH,
+			 "Read/Write to TD VMCS *_HIGH fields not supported");
+
+	BUILD_BUG_ON(bits != 16 && bits != 32 && bits != 64);
+
+#define VMCS_ENC_WIDTH_MASK	GENMASK(14, 13)
+#define VMCS_ENC_WIDTH_16BIT	(0UL << 13)
+#define VMCS_ENC_WIDTH_64BIT	(1UL << 13)
+#define VMCS_ENC_WIDTH_32BIT	(2UL << 13)
+#define VMCS_ENC_WIDTH_NATURAL	(3UL << 13)
+#define VMCS_ENC_WIDTH(field)	((field) & VMCS_ENC_WIDTH_MASK)
+
+	/* TDX is 64bit only.  i.e. natural width = 64bit. */
+	BUILD_BUG_ON_MSG(bits != 64 && __builtin_constant_p(field) &&
+			 (VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_64BIT ||
+			  VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_NATURAL),
+			 "Invalid TD VMCS access for 64-bit field");
+	BUILD_BUG_ON_MSG(bits != 32 && __builtin_constant_p(field) &&
+			 VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_32BIT,
+			 "Invalid TD VMCS access for 32-bit field");
+	BUILD_BUG_ON_MSG(bits != 16 && __builtin_constant_p(field) &&
+			 VMCS_ENC_WIDTH(field) == VMCS_ENC_WIDTH_16BIT,
+			 "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_args out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_rd(tdx->tdvpr_pa, TDVPS_##uclass(field), &out);		\
+	if (KVM_BUG_ON(err, tdx->vcpu.kvm)) {					\
+		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_args 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 (KVM_BUG_ON(err, tdx->vcpu.kvm))					\
+		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_args out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(tdx->tdvpr_pa, TDVPS_##uclass(field), bit, bit, &out);	\
+	if (KVM_BUG_ON(err, tdx->vcpu.kvm))					\
+		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_args out;						\
+	u64 err;								\
+										\
+	tdvps_##lclass##_check(field, bits);					\
+	err = tdh_vp_wr(tdx->tdvpr_pa, TDVPS_##uclass(field), 0, bit, &out);	\
+	if (KVM_BUG_ON(err, tdx->vcpu.kvm))					\
+		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);
+
 static __always_inline u64 td_tdcs_exec_read64(struct kvm_tdx *kvm_tdx, u32 field)
 {
 	struct tdx_module_args out;
-- 
2.25.1