From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> TDX KVM needs system-wide information about the TDX module. Generate the data based on tdx_sysinfo td_conf CPUID data. Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> Co-developed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> Co-developed-by: Tony Lindgren <tony.lindgren@xxxxxxxxxxxxxxx> Signed-off-by: Tony Lindgren <tony.lindgren@xxxxxxxxxxxxxxx> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx> Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> --- - Clarify comment about EAX[23:16] in td_init_cpuid_entry2() (Xiaoyao) - Add comment for configurable CPUID bits (Xiaoyao) Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/include/uapi/asm/kvm.h | 11 +++ arch/x86/kvm/vmx/tdx.c | 137 ++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/tdx_arch.h | 2 + 3 files changed, 150 insertions(+) diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index 2b0317b47e47..8a4633cdb247 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -929,6 +929,8 @@ struct kvm_hyperv_eventfd { /* Trust Domain eXtension sub-ioctl() commands. */ enum kvm_tdx_cmd_id { + KVM_TDX_CAPABILITIES = 0, + KVM_TDX_CMD_NR_MAX, }; @@ -950,4 +952,13 @@ struct kvm_tdx_cmd { __u64 hw_error; }; +struct kvm_tdx_capabilities { + __u64 supported_attrs; + __u64 supported_xfam; + __u64 reserved[254]; + + /* Configurable CPUID bits for userspace */ + struct kvm_cpuid2 cpuid; +}; + #endif /* _ASM_X86_KVM_H */ diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 08880ac9c77b..630d19114429 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -33,6 +33,8 @@ static enum cpuhp_state tdx_cpuhp_state; static const struct tdx_sys_info *tdx_sysinfo; +#define KVM_SUPPORTED_TD_ATTRS (TDX_TD_ATTR_SEPT_VE_DISABLE) + static __always_inline struct kvm_tdx *to_kvm_tdx(struct kvm *kvm) { return container_of(kvm, struct kvm_tdx, kvm); @@ -43,6 +45,129 @@ static __always_inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu) return container_of(vcpu, struct vcpu_tdx, vcpu); } +static u64 tdx_get_supported_attrs(const struct tdx_sys_info_td_conf *td_conf) +{ + u64 val = KVM_SUPPORTED_TD_ATTRS; + + if ((val & td_conf->attributes_fixed1) != td_conf->attributes_fixed1) + return 0; + + val &= td_conf->attributes_fixed0; + + return val; +} + +static u64 tdx_get_supported_xfam(const struct tdx_sys_info_td_conf *td_conf) +{ + u64 val = kvm_caps.supported_xcr0 | kvm_caps.supported_xss; + + if ((val & td_conf->xfam_fixed1) != td_conf->xfam_fixed1) + return 0; + + val &= td_conf->xfam_fixed0; + + return val; +} + +static u32 tdx_set_guest_phys_addr_bits(const u32 eax, int addr_bits) +{ + return (eax & ~GENMASK(23, 16)) | (addr_bits & 0xff) << 16; +} + +#define KVM_TDX_CPUID_NO_SUBLEAF ((__u32)-1) + +static void td_init_cpuid_entry2(struct kvm_cpuid_entry2 *entry, unsigned char idx) +{ + const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf; + + entry->function = (u32)td_conf->cpuid_config_leaves[idx]; + entry->index = td_conf->cpuid_config_leaves[idx] >> 32; + entry->eax = (u32)td_conf->cpuid_config_values[idx][0]; + entry->ebx = td_conf->cpuid_config_values[idx][0] >> 32; + entry->ecx = (u32)td_conf->cpuid_config_values[idx][1]; + entry->edx = td_conf->cpuid_config_values[idx][1] >> 32; + + if (entry->index == KVM_TDX_CPUID_NO_SUBLEAF) + entry->index = 0; + + /* + * The TDX module doesn't allow configuring the guest phys addr bits + * (EAX[23:16]). However, KVM uses it as an interface to the userspace + * to configure the GPAW. Report these bits as configurable. + */ + if (entry->function == 0x80000008) + entry->eax = tdx_set_guest_phys_addr_bits(entry->eax, 0xff); +} + +static int init_kvm_tdx_caps(const struct tdx_sys_info_td_conf *td_conf, + struct kvm_tdx_capabilities *caps) +{ + int i; + + caps->supported_attrs = tdx_get_supported_attrs(td_conf); + if (!caps->supported_attrs) + return -EIO; + + caps->supported_xfam = tdx_get_supported_xfam(td_conf); + if (!caps->supported_xfam) + return -EIO; + + caps->cpuid.nent = td_conf->num_cpuid_config; + + for (i = 0; i < td_conf->num_cpuid_config; i++) + td_init_cpuid_entry2(&caps->cpuid.entries[i], i); + + return 0; +} + +static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) +{ + const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf; + struct kvm_tdx_capabilities __user *user_caps; + struct kvm_tdx_capabilities *caps = NULL; + int ret = 0; + + /* flags is reserved for future use */ + if (cmd->flags) + return -EINVAL; + + caps = kmalloc(sizeof(*caps) + + sizeof(struct kvm_cpuid_entry2) * td_conf->num_cpuid_config, + GFP_KERNEL); + if (!caps) + return -ENOMEM; + + user_caps = u64_to_user_ptr(cmd->data); + if (copy_from_user(caps, user_caps, sizeof(*caps))) { + ret = -EFAULT; + goto out; + } + + if (caps->cpuid.nent < td_conf->num_cpuid_config) { + ret = -E2BIG; + goto out; + } + + ret = init_kvm_tdx_caps(td_conf, caps); + if (ret) + goto out; + + if (copy_to_user(user_caps, caps, sizeof(*caps))) { + ret = -EFAULT; + goto out; + } + + if (copy_to_user(user_caps->cpuid.entries, caps->cpuid.entries, + caps->cpuid.nent * + sizeof(caps->cpuid.entries[0]))) + ret = -EFAULT; + +out: + /* kfree() accepts NULL. */ + kfree(caps); + return ret; +} + int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { struct kvm_tdx_cmd tdx_cmd; @@ -61,6 +186,9 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) mutex_lock(&kvm->lock); switch (tdx_cmd.id) { + case KVM_TDX_CAPABILITIES: + r = tdx_get_capabilities(&tdx_cmd); + break; default: r = -EINVAL; goto out; @@ -158,11 +286,20 @@ static int __init __tdx_bringup(void) goto get_sysinfo_err; } + /* Check TDX module and KVM capabilities */ + if (!tdx_get_supported_attrs(&tdx_sysinfo->td_conf) || + !tdx_get_supported_xfam(&tdx_sysinfo->td_conf)) + goto get_sysinfo_err; + + if (!(tdx_sysinfo->features.tdx_features0 & MD_FIELD_ID_FEATURES0_TOPOLOGY_ENUM)) + goto get_sysinfo_err; + /* * Leave hardware virtualization enabled after TDX is enabled * successfully. TDX CPU hotplug depends on this. */ return 0; + get_sysinfo_err: __do_tdx_cleanup(); tdx_bringup_err: diff --git a/arch/x86/kvm/vmx/tdx_arch.h b/arch/x86/kvm/vmx/tdx_arch.h index fb7abe9fef8e..cb9a638fa398 100644 --- a/arch/x86/kvm/vmx/tdx_arch.h +++ b/arch/x86/kvm/vmx/tdx_arch.h @@ -120,4 +120,6 @@ struct td_params { #define TDX_MIN_TSC_FREQUENCY_KHZ (100 * 1000) #define TDX_MAX_TSC_FREQUENCY_KHZ (10 * 1000 * 1000) +#define MD_FIELD_ID_FEATURES0_TOPOLOGY_ENUM BIT_ULL(20) + #endif /* __KVM_X86_TDX_ARCH_H */ -- 2.43.5