[PATCH v19 034/130] KVM: TDX: Get system-wide info about TDX module on initialization

isaku.yamahata
2024-02-26T08:28:01Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

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

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
v19:
- Added features0
- Use tdx_sys_metadata_read()
- Fix error recovery path by Yuan

Change v18:
- Newly Added

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
arch/x86/include/uapi/asm/kvm.h | 11 +++++
arch/x86/kvm/vmx/main.c | 9 +++-
arch/x86/kvm/vmx/tdx.c | 80 ++++++++++++++++++++++++++++++++-
arch/x86/kvm/vmx/x86_ops.h | 2 +
4 files changed, 100 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 fa19682b366c..a948a6959ac7 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -32,6 +32,13 @@ 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))
@@ -54,7 +61,7 @@ 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,

/* TDX cpu enablement is done by tdx_hardware_setup(). */
.hardware_enable = vmx_hardware_enable,
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index dce21f675155..5edfb99abb89 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -40,6 +40,21 @@ static void __used tdx_guest_keyid_free(int keyid)
ida_free(&tdx_guest_keyid_pool, keyid);
}

+struct tdx_info {
+ u64 features0;
+ 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;
+
#define TDX_MD_MAP(_fid, _ptr) \
{ .fid = MD_FIELD_ID_##_fid, \
.ptr = (_ptr), }
@@ -66,7 +81,7 @@ static size_t tdx_md_element_size(u64 fid)
}
}

-static int __used 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;
@@ -84,9 +99,26 @@ static int __used tdx_md_read(struct tdx_md_map *maps, int nr_maps)
return 0;
}

+#define TDX_INFO_MAP(_field_id, _member) \
+ TD_SYSINFO_MAP(_field_id, struct tdx_info, _member)
+
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),
+ };
+
+ struct tdx_metadata_field_mapping fields[] = {
+ TDX_INFO_MAP(FEATURES0, features0),
+ 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) {
@@ -94,7 +126,48 @@ 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(fields, ARRAY_SIZE(fields), tdx_info);
+ if (ret)
+ goto error_out;
+
+ 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_out;
+
+ 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_out:
+ /* kfree() accepts NULL. */
+ kfree(tdx_info);
+ return ret;
}

bool tdx_is_vm_type_supported(unsigned long type)
@@ -162,3 +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 f4da88a228d0..e8cb4ae81cf1 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