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

Binbin Wu
2024-03-14T15:06:15Z

On 2/26/2024 4:25 PM, isaku.yamahata@intel.com wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
>
> TDX KVM needs system-wide information about the TDX module, store it in
> struct tdx_info.

Nit: Maybe you can add some description about hardware_unsetup()?

Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>

> 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
>