Commit Message
Isaku Yamahata
Feb. 26, 2024, 8:25 a.m. UTC
From: Sean Christopherson <sean.j.christopherson@intel.com> Implement an ioctl to get system-wide parameters for TDX. Although the function is systemwide, vm scoped mem_enc ioctl works for userspace VMM like qemu and device scoped version is not define, re-use vm scoped mem_enc. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> --- v18: - drop the use of tdhsysinfo_struct and TDH.SYS.INFO, use TDH.SYS.RD(). For that, dynamically allocate/free tdx_info. - drop the change of tools/arch/x86/include/uapi/asm/kvm.h. v14 -> v15: - ABI change: added supported_gpaw and reserved area. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> --- arch/x86/include/uapi/asm/kvm.h | 17 ++++++++++ arch/x86/kvm/vmx/tdx.c | 56 +++++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/tdx.h | 3 ++ 3 files changed, 76 insertions(+)
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h index 9ea46d143bef..e28189c81691 100644 --- a/arch/x86/include/uapi/asm/kvm.h +++ b/arch/x86/include/uapi/asm/kvm.h @@ -604,4 +604,21 @@ struct kvm_tdx_cpuid_config { __u32 edx; }; +/* supported_gpaw */ +#define TDX_CAP_GPAW_48 (1 << 0) +#define TDX_CAP_GPAW_52 (1 << 1) + +struct kvm_tdx_capabilities { + __u64 attrs_fixed0; + __u64 attrs_fixed1; + __u64 xfam_fixed0; + __u64 xfam_fixed1; + __u32 supported_gpaw; + __u32 padding; + __u64 reserved[251]; + + __u32 nr_cpuid_configs; + struct kvm_tdx_cpuid_config cpuid_configs[]; +}; + #endif /* _ASM_X86_KVM_H */ diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 07a3f0f75f87..816ccdb4bc41 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -6,6 +6,7 @@ #include "capabilities.h" #include "x86_ops.h" #include "x86.h" +#include "mmu.h" #include "tdx_arch.h" #include "tdx.h" @@ -55,6 +56,58 @@ struct tdx_info { /* Info about the TDX module. */ static struct tdx_info *tdx_info; +static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) +{ + struct kvm_tdx_capabilities __user *user_caps; + struct kvm_tdx_capabilities *caps = NULL; + int ret = 0; + + if (cmd->flags) + return -EINVAL; + + caps = kmalloc(sizeof(*caps), GFP_KERNEL); + if (!caps) + return -ENOMEM; + + user_caps = (void __user *)cmd->data; + if (copy_from_user(caps, user_caps, sizeof(*caps))) { + ret = -EFAULT; + goto out; + } + + if (caps->nr_cpuid_configs < tdx_info->num_cpuid_config) { + ret = -E2BIG; + goto out; + } + + *caps = (struct kvm_tdx_capabilities) { + .attrs_fixed0 = tdx_info->attributes_fixed0, + .attrs_fixed1 = tdx_info->attributes_fixed1, + .xfam_fixed0 = tdx_info->xfam_fixed0, + .xfam_fixed1 = tdx_info->xfam_fixed1, + .supported_gpaw = TDX_CAP_GPAW_48 | + ((kvm_get_shadow_phys_bits() >= 52 && + cpu_has_vmx_ept_5levels()) ? TDX_CAP_GPAW_52 : 0), + .nr_cpuid_configs = tdx_info->num_cpuid_config, + .padding = 0, + }; + + if (copy_to_user(user_caps, caps, sizeof(*caps))) { + ret = -EFAULT; + goto out; + } + if (copy_to_user(user_caps->cpuid_configs, &tdx_info->cpuid_configs, + tdx_info->num_cpuid_config * + sizeof(tdx_info->cpuid_configs[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; @@ -68,6 +121,9 @@ 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; diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 473013265bd8..22c0b57f69ca 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -3,6 +3,9 @@ #define __KVM_X86_TDX_H #ifdef CONFIG_INTEL_TDX_HOST + +#include "tdx_ops.h" + struct kvm_tdx { struct kvm kvm; /* TDX specific members follow. */