[PATCH v18 020/121] x86/virt/tdx: Get system-wide info about TDX module on initialization

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

TDX KVM needs system-wide information about the TDX module, store it in
struct tdx_info.

TODO: Once TDX host patch series introduces a framework to read TDX meta
data, convert the code to it.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
Change v18:
- Newly Added
---
 arch/x86/include/uapi/asm/kvm.h | 11 +++++
 arch/x86/kvm/vmx/main.c         |  9 +++-
 arch/x86/kvm/vmx/tdx.c          | 79 ++++++++++++++++++++++++++++++++-
 arch/x86/kvm/vmx/x86_ops.h      |  2 +
 4 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index aa7a56a47564..45b2c2304491 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -567,4 +567,15 @@ struct kvm_pmu_event_filter {
 #define KVM_X86_TDX_VM		2
 #define KVM_X86_SNP_VM		3
 
+#define KVM_TDX_CPUID_NO_SUBLEAF	((__u32)-1)
+
+struct kvm_tdx_cpuid_config {
+	__u32 leaf;
+	__u32 sub_leaf;
+	__u32 eax;
+	__u32 ebx;
+	__u32 ecx;
+	__u32 edx;
+};
+
 #endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index 62236bde3779..f181620b2922 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -47,6 +47,13 @@ static __init int vt_hardware_setup(void)
 	return 0;
 }
 
+static void vt_hardware_unsetup(void)
+{
+	if (enable_tdx)
+		tdx_hardware_unsetup();
+	vmx_hardware_unsetup();
+}
+
 static int vt_vm_init(struct kvm *kvm)
 {
 	if (is_td(kvm))
@@ -69,7 +76,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
 
 	.check_processor_compatibility = vmx_check_processor_compat,
 
-	.hardware_unsetup = vmx_hardware_unsetup,
+	.hardware_unsetup = vt_hardware_unsetup,
 
 	.hardware_enable = vt_hardware_enable,
 	.hardware_disable = vmx_hardware_disable,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 1608bdf2381d..55399136b680 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -67,7 +67,7 @@ static size_t tdx_md_element_size(u64 fid)
 	}
 }
 
-int tdx_md_read(struct tdx_md_map *maps, int nr_maps)
+static int tdx_md_read(struct tdx_md_map *maps, int nr_maps)
 {
 	struct tdx_md_map *m;
 	int ret, i;
@@ -85,9 +85,39 @@ int tdx_md_read(struct tdx_md_map *maps, int nr_maps)
 	return 0;
 }
 
+struct tdx_info {
+	u64 attributes_fixed0;
+	u64 attributes_fixed1;
+	u64 xfam_fixed0;
+	u64 xfam_fixed1;
+
+	u16 num_cpuid_config;
+	/* This must the last member. */
+	DECLARE_FLEX_ARRAY(struct kvm_tdx_cpuid_config, cpuid_configs);
+};
+
+/* Info about the TDX module. */
+static struct tdx_info *tdx_info;
+
 static int __init tdx_module_setup(void)
 {
+	u16 num_cpuid_config;
 	int ret;
+	u32 i;
+
+	struct tdx_md_map mds[] = {
+		TDX_MD_MAP(NUM_CPUID_CONFIG, &num_cpuid_config),
+	};
+
+#define TDX_INFO_MAP(_field_id, _member)			\
+	TD_SYSINFO_MAP(_field_id, struct tdx_info, _member)
+
+	struct tdx_metadata_field_mapping tdx_info_md[] = {
+		TDX_INFO_MAP(ATTRS_FIXED0, attributes_fixed0),
+		TDX_INFO_MAP(ATTRS_FIXED1, attributes_fixed1),
+		TDX_INFO_MAP(XFAM_FIXED0, xfam_fixed0),
+		TDX_INFO_MAP(XFAM_FIXED1, xfam_fixed1),
+	};
 
 	ret = tdx_enable();
 	if (ret) {
@@ -95,7 +125,49 @@ static int __init tdx_module_setup(void)
 		return ret;
 	}
 
+	ret = tdx_md_read(mds, ARRAY_SIZE(mds));
+	if (ret)
+		return ret;
+
+	tdx_info = kzalloc(sizeof(*tdx_info) +
+			   sizeof(*tdx_info->cpuid_configs) * num_cpuid_config,
+			   GFP_KERNEL);
+	if (!tdx_info)
+		return -ENOMEM;
+	tdx_info->num_cpuid_config = num_cpuid_config;
+
+	ret = tdx_sys_metadata_read(tdx_info_md, ARRAY_SIZE(tdx_info_md), tdx_info);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < num_cpuid_config; i++) {
+		struct kvm_tdx_cpuid_config *c = &tdx_info->cpuid_configs[i];
+		u64 leaf, eax_ebx, ecx_edx;
+		struct tdx_md_map cpuids[] = {
+			TDX_MD_MAP(CPUID_CONFIG_LEAVES + i, &leaf),
+			TDX_MD_MAP(CPUID_CONFIG_VALUES + i * 2, &eax_ebx),
+			TDX_MD_MAP(CPUID_CONFIG_VALUES + i * 2 + 1, &ecx_edx),
+		};
+
+		ret = tdx_md_read(cpuids, ARRAY_SIZE(cpuids));
+		if (ret)
+			goto error_sys_rd;
+
+		c->leaf = (u32)leaf;
+		c->sub_leaf = leaf >> 32;
+		c->eax = (u32)eax_ebx;
+		c->ebx = eax_ebx >> 32;
+		c->ecx = (u32)ecx_edx;
+		c->edx = ecx_edx >> 32;
+	}
+
 	return 0;
+
+error_sys_rd:
+	ret = -EIO;
+	/* kfree() accepts NULL. */
+	kfree(tdx_info);
+	return ret;
 }
 
 bool tdx_is_vm_type_supported(unsigned long type)
@@ -163,3 +235,8 @@ int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
 out:
 	return r;
 }
+
+void tdx_hardware_unsetup(void)
+{
+	kfree(tdx_info);
+}
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 5da7a5fd91cb..9523087ae355 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -136,9 +136,11 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu);
 
 #ifdef CONFIG_INTEL_TDX_HOST
 int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops);
+void tdx_hardware_unsetup(void);
 bool tdx_is_vm_type_supported(unsigned long type);
 #else
 static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return -EOPNOTSUPP; }
+static inline void tdx_hardware_unsetup(void) {}
 static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; }
 #endif
 
-- 
2.25.1