From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
After the crypto-protection key has been configured, TDX requires a
VM-scope initialization as a step of creating the TDX guest. This
"per-VM" TDX initialization does the global configurations/features that
the TDX guest can support, such as guest's CPUIDs (emulated by the TDX
module), the maximum number of vcpus etc.
Because there is no room in KVM_CREATE_VM to pass all the required
parameters, introduce a new ioctl KVM_TDX_INIT_VM and mark the VM as
TD_STATE_UNINITIALIZED until it is invoked.
This "per-VM" TDX initialization must be done before any "vcpu-scope" TDX
initialization; KVM_TDX_INIT_VM IOCTL must be invoked before the creation
of vCPUs.
Co-developed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/include/uapi/asm/kvm.h | 24 +++
arch/x86/kvm/vmx/tdx.c | 258 ++++++++++++++++++++++++++++++--
arch/x86/kvm/vmx/tdx.h | 25 ++++
3 files changed, 297 insertions(+), 10 deletions(-)
diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 8a4633cdb247..b64351076f2a 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -930,6 +930,7 @@ struct kvm_hyperv_eventfd {
/* Trust Domain eXtension sub-ioctl() commands. */
enum kvm_tdx_cmd_id {
KVM_TDX_CAPABILITIES = 0,
+ KVM_TDX_INIT_VM,
KVM_TDX_CMD_NR_MAX,
};
@@ -961,4 +962,27 @@ struct kvm_tdx_capabilities {
struct kvm_cpuid2 cpuid;
};
+struct kvm_tdx_init_vm {
+ __u64 attributes;
+ __u64 xfam;
+ __u64 mrconfigid[6]; /* sha384 digest */
+ __u64 mrowner[6]; /* sha384 digest */
+ __u64 mrownerconfig[6]; /* sha384 digest */
+
+ /* The total space for TD_PARAMS before the CPUIDs is 256 bytes */
+ __u64 reserved[12];
+
+ /*
+ * Call KVM_TDX_INIT_VM before vcpu creation, thus before
+ * KVM_SET_CPUID2.
+ * This configuration supersedes KVM_SET_CPUID2s for VCPUs because the
+ * TDX module directly virtualizes those CPUIDs without VMM. The user
+ * space VMM, e.g. qemu, should make KVM_SET_CPUID2 consistent with
+ * those values. If it doesn't, KVM may have wrong idea of vCPUIDs of
+ * the guest, and KVM may wrongly emulate CPUIDs or MSRs that the TDX
+ * module doesn't virtualize.
+ */
+ 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 cebe570f2002..1d1bdc70f4ae 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -69,6 +69,11 @@ static u64 tdx_get_supported_xfam(const struct tdx_sys_info_td_conf *td_conf)
return val;
}
+static int tdx_get_guest_phys_addr_bits(const u32 eax)
+{
+ return (eax & GENMASK(23, 16)) >> 16;
+}
+
static u32 tdx_set_guest_phys_addr_bits(const u32 eax, int addr_bits)
{
return (eax & ~GENMASK(23, 16)) | (addr_bits & 0xff) << 16;
@@ -350,7 +355,11 @@ static void tdx_reclaim_td_control_pages(struct kvm *kvm)
void tdx_vm_destroy(struct kvm *kvm)
{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
tdx_reclaim_td_control_pages(kvm);
+
+ kvm_tdx->state = TD_STATE_UNINITIALIZED;
}
static int tdx_do_tdh_mng_key_config(void *param)
@@ -369,10 +378,10 @@ static int tdx_do_tdh_mng_key_config(void *param)
return 0;
}
-static int __tdx_td_init(struct kvm *kvm);
-
int tdx_vm_init(struct kvm *kvm)
{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
kvm->arch.has_protected_state = true;
kvm->arch.has_private_mem = true;
@@ -389,8 +398,9 @@ int tdx_vm_init(struct kvm *kvm)
*/
kvm->max_vcpus = min_t(int, kvm->max_vcpus, num_present_cpus());
- /* Place holder for TDX specific logic. */
- return __tdx_td_init(kvm);
+ kvm_tdx->state = TD_STATE_UNINITIALIZED;
+
+ return 0;
}
static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
@@ -441,15 +451,151 @@ static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
return ret;
}
-static int __tdx_td_init(struct kvm *kvm)
+/*
+ * KVM reports guest physical address in CPUID.0x800000008.EAX[23:16], which is
+ * similar to TDX's GPAW. Use this field as the interface for userspace to
+ * configure the GPAW and EPT level for TDs.
+ *
+ * Only values 48 and 52 are supported. Value 52 means GPAW-52 and EPT level
+ * 5, Value 48 means GPAW-48 and EPT level 4. For value 48, GPAW-48 is always
+ * supported. Value 52 is only supported when the platform supports 5 level
+ * EPT.
+ */
+static int setup_tdparams_eptp_controls(struct kvm_cpuid2 *cpuid,
+ struct td_params *td_params)
+{
+ const struct kvm_cpuid_entry2 *entry;
+ int guest_pa;
+
+ entry = kvm_find_cpuid_entry2(cpuid->entries, cpuid->nent, 0x80000008, 0);
+ if (!entry)
+ return -EINVAL;
+
+ guest_pa = tdx_get_guest_phys_addr_bits(entry->eax);
+
+ if (guest_pa != 48 && guest_pa != 52)
+ return -EINVAL;
+
+ if (guest_pa == 52 && !cpu_has_vmx_ept_5levels())
+ return -EINVAL;
+
+ td_params->eptp_controls = VMX_EPTP_MT_WB;
+ if (guest_pa == 52) {
+ td_params->eptp_controls |= VMX_EPTP_PWL_5;
+ td_params->config_flags |= TDX_CONFIG_FLAGS_MAX_GPAW;
+ } else {
+ td_params->eptp_controls |= VMX_EPTP_PWL_4;
+ }
+
+ return 0;
+}
+
+static int setup_tdparams_cpuids(struct kvm_cpuid2 *cpuid,
+ struct td_params *td_params)
+{
+ const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf;
+ const struct kvm_cpuid_entry2 *entry;
+ struct tdx_cpuid_value *value;
+ int i, copy_cnt = 0;
+
+ /*
+ * td_params.cpuid_values: The number and the order of cpuid_value must
+ * be same to the one of struct tdsysinfo.{num_cpuid_config, cpuid_configs}
+ * It's assumed that td_params was zeroed.
+ */
+ for (i = 0; i < td_conf->num_cpuid_config; i++) {
+ struct kvm_cpuid_entry2 tmp;
+
+ td_init_cpuid_entry2(&tmp, i);
+
+ entry = kvm_find_cpuid_entry2(cpuid->entries, cpuid->nent,
+ tmp.function, tmp.index);
+ if (!entry)
+ continue;
+
+ copy_cnt++;
+
+ value = &td_params->cpuid_values[i];
+ value->eax = entry->eax;
+ value->ebx = entry->ebx;
+ value->ecx = entry->ecx;
+ value->edx = entry->edx;
+
+ /*
+ * TDX module does not accept nonzero bits 16..23 for the
+ * CPUID[0x80000008].EAX, see setup_tdparams_eptp_controls().
+ */
+ if (tmp.function == 0x80000008)
+ value->eax = tdx_set_guest_phys_addr_bits(value->eax, 0);
+ }
+
+ /*
+ * Rely on the TDX module to reject invalid configuration, but it can't
+ * check of leafs that don't have a proper slot in td_params->cpuid_values
+ * to stick then. So fail if there were entries that didn't get copied to
+ * td_params.
+ */
+ if (copy_cnt != cpuid->nent)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int setup_tdparams(struct kvm *kvm, struct td_params *td_params,
+ struct kvm_tdx_init_vm *init_vm)
+{
+ const struct tdx_sys_info_td_conf *td_conf = &tdx_sysinfo->td_conf;
+ struct kvm_cpuid2 *cpuid = &init_vm->cpuid;
+ int ret;
+
+ if (kvm->created_vcpus)
+ return -EBUSY;
+
+ if (init_vm->attributes & ~tdx_get_supported_attrs(td_conf))
+ return -EINVAL;
+
+ if (init_vm->xfam & ~tdx_get_supported_xfam(td_conf))
+ return -EINVAL;
+
+ td_params->max_vcpus = kvm->max_vcpus;
+ td_params->attributes = init_vm->attributes | td_conf->attributes_fixed1;
+ td_params->xfam = init_vm->xfam | td_conf->xfam_fixed1;
+
+ td_params->config_flags = TDX_CONFIG_FLAGS_NO_RBP_MOD;
+ td_params->tsc_frequency = TDX_TSC_KHZ_TO_25MHZ(kvm->arch.default_tsc_khz);
+
+ ret = setup_tdparams_eptp_controls(cpuid, td_params);
+ if (ret)
+ return ret;
+
+ ret = setup_tdparams_cpuids(cpuid, td_params);
+ if (ret)
+ return ret;
+
+#define MEMCPY_SAME_SIZE(dst, src) \
+ do { \
+ BUILD_BUG_ON(sizeof(dst) != sizeof(src)); \
+ memcpy((dst), (src), sizeof(dst)); \
+ } while (0)
+
+ MEMCPY_SAME_SIZE(td_params->mrconfigid, init_vm->mrconfigid);
+ MEMCPY_SAME_SIZE(td_params->mrowner, init_vm->mrowner);
+ MEMCPY_SAME_SIZE(td_params->mrownerconfig, init_vm->mrownerconfig);
+
+ return 0;
+}
+
+static int __tdx_td_init(struct kvm *kvm, struct td_params *td_params,
+ u64 *seamcall_err)
{
struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
cpumask_var_t packages;
struct page **tdcs_pages = NULL;
struct page *tdr_page;
int ret, i;
- u64 err;
+ u64 err, rcx;
+ *seamcall_err = 0;
ret = tdx_guest_keyid_alloc();
if (ret < 0)
return ret;
@@ -561,10 +707,23 @@ static int __tdx_td_init(struct kvm *kvm)
}
}
- /*
- * Note, TDH_MNG_INIT cannot be invoked here. TDH_MNG_INIT requires a dedicated
- * ioctl() to define the configure CPUID values for the TD.
- */
+ err = tdh_mng_init(&kvm_tdx->td, __pa(td_params), &rcx);
+ if ((err & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_INVALID) {
+ /*
+ * Because a user gives operands, don't warn.
+ * Return a hint to the user because it's sometimes hard for the
+ * user to figure out which operand is invalid. SEAMCALL status
+ * code includes which operand caused invalid operand error.
+ */
+ *seamcall_err = err;
+ ret = -EINVAL;
+ goto teardown;
+ } else if (WARN_ON_ONCE(err)) {
+ pr_tdx_error_1(TDH_MNG_INIT, err, rcx);
+ ret = -EIO;
+ goto teardown;
+ }
+
return 0;
/*
@@ -612,6 +771,82 @@ static int __tdx_td_init(struct kvm *kvm)
return ret;
}
+static int tdx_td_init(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
+{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ struct kvm_tdx_init_vm *init_vm;
+ struct td_params *td_params = NULL;
+ int ret;
+
+ BUILD_BUG_ON(sizeof(*init_vm) != 256 + sizeof_field(struct kvm_tdx_init_vm, cpuid));
+ BUILD_BUG_ON(sizeof(struct td_params) != 1024);
+
+ if (kvm_tdx->state != TD_STATE_UNINITIALIZED)
+ return -EINVAL;
+
+ if (cmd->flags)
+ return -EINVAL;
+
+ init_vm = kmalloc(sizeof(*init_vm) +
+ sizeof(init_vm->cpuid.entries[0]) * KVM_MAX_CPUID_ENTRIES,
+ GFP_KERNEL);
+ if (!init_vm)
+ return -ENOMEM;
+
+ if (copy_from_user(init_vm, u64_to_user_ptr(cmd->data), sizeof(*init_vm))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (init_vm->cpuid.nent > KVM_MAX_CPUID_ENTRIES) {
+ ret = -E2BIG;
+ goto out;
+ }
+
+ if (copy_from_user(init_vm->cpuid.entries,
+ u64_to_user_ptr(cmd->data) + sizeof(*init_vm),
+ flex_array_size(init_vm, cpuid.entries, init_vm->cpuid.nent))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if (memchr_inv(init_vm->reserved, 0, sizeof(init_vm->reserved))) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (init_vm->cpuid.padding) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ td_params = kzalloc(sizeof(struct td_params), GFP_KERNEL);
+ if (!td_params) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = setup_tdparams(kvm, td_params, init_vm);
+ if (ret)
+ goto out;
+
+ ret = __tdx_td_init(kvm, td_params, &cmd->hw_error);
+ if (ret)
+ goto out;
+
+ kvm_tdx->tsc_offset = td_tdcs_exec_read64(kvm_tdx, TD_TDCS_EXEC_TSC_OFFSET);
+ kvm_tdx->attributes = td_params->attributes;
+ kvm_tdx->xfam = td_params->xfam;
+
+ kvm_tdx->state = TD_STATE_INITIALIZED;
+out:
+ /* kfree() accepts NULL. */
+ kfree(init_vm);
+ kfree(td_params);
+
+ return ret;
+}
+
int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
{
struct kvm_tdx_cmd tdx_cmd;
@@ -633,6 +868,9 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
case KVM_TDX_CAPABILITIES:
r = tdx_get_capabilities(&tdx_cmd);
break;
+ case KVM_TDX_INIT_VM:
+ r = tdx_td_init(kvm, &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 8102461f775d..f12854c8ff07 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -11,9 +11,23 @@ void tdx_cleanup(void);
extern bool enable_tdx;
+/* TDX module hardware states. These follow the TDX module OP_STATEs. */
+enum kvm_tdx_state {
+ TD_STATE_UNINITIALIZED = 0,
+ TD_STATE_INITIALIZED,
+ TD_STATE_RUNNABLE,
+};
+
struct kvm_tdx {
struct kvm kvm;
+
int hkid;
+ enum kvm_tdx_state state;
+
+ u64 attributes;
+ u64 xfam;
+
+ u64 tsc_offset;
struct tdx_td td;
};
@@ -33,6 +47,17 @@ static inline bool is_td_vcpu(struct kvm_vcpu *vcpu)
return is_td(vcpu->kvm);
}
+static __always_inline u64 td_tdcs_exec_read64(struct kvm_tdx *kvm_tdx, u32 field)
+{
+ u64 err, data;
+
+ err = tdh_mng_rd(&kvm_tdx->td, TDCS_EXEC(field), &data);
+ if (unlikely(err)) {
+ pr_err("TDH_MNG_RD[EXEC.0x%x] failed: 0x%llx\n", field, err);
+ return 0;
+ }
+ return data;
+}
#else
static inline int tdx_bringup(void) { return 0; }
static inline void tdx_cleanup(void) {}
--
2.43.5
