diff options
Diffstat (limited to 'arch/x86/kvm/vmx/tdx.c')
| -rw-r--r-- | arch/x86/kvm/vmx/tdx.c | 3526 |
1 files changed, 3526 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c new file mode 100644 index 000000000000..b952bc673271 --- /dev/null +++ b/arch/x86/kvm/vmx/tdx.c @@ -0,0 +1,3526 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/cleanup.h> +#include <linux/cpu.h> +#include <asm/cpufeature.h> +#include <asm/fpu/xcr.h> +#include <linux/misc_cgroup.h> +#include <linux/mmu_context.h> +#include <asm/tdx.h> +#include "capabilities.h" +#include "mmu.h" +#include "x86_ops.h" +#include "lapic.h" +#include "tdx.h" +#include "vmx.h" +#include "mmu/spte.h" +#include "common.h" +#include "posted_intr.h" +#include "irq.h" +#include <trace/events/kvm.h> +#include "trace.h" + +#pragma GCC poison to_vmx + +#undef pr_fmt +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#define pr_tdx_error(__fn, __err) \ + pr_err_ratelimited("SEAMCALL %s failed: 0x%llx\n", #__fn, __err) + +#define __pr_tdx_error_N(__fn_str, __err, __fmt, ...) \ + pr_err_ratelimited("SEAMCALL " __fn_str " failed: 0x%llx, " __fmt, __err, __VA_ARGS__) + +#define pr_tdx_error_1(__fn, __err, __rcx) \ + __pr_tdx_error_N(#__fn, __err, "rcx 0x%llx\n", __rcx) + +#define pr_tdx_error_2(__fn, __err, __rcx, __rdx) \ + __pr_tdx_error_N(#__fn, __err, "rcx 0x%llx, rdx 0x%llx\n", __rcx, __rdx) + +#define pr_tdx_error_3(__fn, __err, __rcx, __rdx, __r8) \ + __pr_tdx_error_N(#__fn, __err, "rcx 0x%llx, rdx 0x%llx, r8 0x%llx\n", __rcx, __rdx, __r8) + +bool enable_tdx __ro_after_init; +module_param_named(tdx, enable_tdx, bool, 0444); + +#define TDX_SHARED_BIT_PWL_5 gpa_to_gfn(BIT_ULL(51)) +#define TDX_SHARED_BIT_PWL_4 gpa_to_gfn(BIT_ULL(47)) + +static enum cpuhp_state tdx_cpuhp_state; + +static const struct tdx_sys_info *tdx_sysinfo; + +void tdh_vp_rd_failed(struct vcpu_tdx *tdx, char *uclass, u32 field, u64 err) +{ + KVM_BUG_ON(1, tdx->vcpu.kvm); + pr_err("TDH_VP_RD[%s.0x%x] failed 0x%llx\n", uclass, field, err); +} + +void tdh_vp_wr_failed(struct vcpu_tdx *tdx, char *uclass, char *op, u32 field, + u64 val, u64 err) +{ + KVM_BUG_ON(1, tdx->vcpu.kvm); + pr_err("TDH_VP_WR[%s.0x%x]%s0x%llx failed: 0x%llx\n", uclass, field, op, val, err); +} + +#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); +} + +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 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; +} + +#define TDX_FEATURE_TSX (__feature_bit(X86_FEATURE_HLE) | __feature_bit(X86_FEATURE_RTM)) + +static bool has_tsx(const struct kvm_cpuid_entry2 *entry) +{ + return entry->function == 7 && entry->index == 0 && + (entry->ebx & TDX_FEATURE_TSX); +} + +static void clear_tsx(struct kvm_cpuid_entry2 *entry) +{ + entry->ebx &= ~TDX_FEATURE_TSX; +} + +static bool has_waitpkg(const struct kvm_cpuid_entry2 *entry) +{ + return entry->function == 7 && entry->index == 0 && + (entry->ecx & __feature_bit(X86_FEATURE_WAITPKG)); +} + +static void clear_waitpkg(struct kvm_cpuid_entry2 *entry) +{ + entry->ecx &= ~__feature_bit(X86_FEATURE_WAITPKG); +} + +static void tdx_clear_unsupported_cpuid(struct kvm_cpuid_entry2 *entry) +{ + if (has_tsx(entry)) + clear_tsx(entry); + + if (has_waitpkg(entry)) + clear_waitpkg(entry); +} + +static bool tdx_unsupported_cpuid(const struct kvm_cpuid_entry2 *entry) +{ + return has_tsx(entry) || has_waitpkg(entry); +} + +#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); + + tdx_clear_unsupported_cpuid(entry); +} + +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; +} + +/* + * Some SEAMCALLs acquire the TDX module globally, and can fail with + * TDX_OPERAND_BUSY. Use a global mutex to serialize these SEAMCALLs. + */ +static DEFINE_MUTEX(tdx_lock); + +static atomic_t nr_configured_hkid; + +static bool tdx_operand_busy(u64 err) +{ + return (err & TDX_SEAMCALL_STATUS_MASK) == TDX_OPERAND_BUSY; +} + + +/* + * A per-CPU list of TD vCPUs associated with a given CPU. + * Protected by interrupt mask. Only manipulated by the CPU owning this per-CPU + * list. + * - When a vCPU is loaded onto a CPU, it is removed from the per-CPU list of + * the old CPU during the IPI callback running on the old CPU, and then added + * to the per-CPU list of the new CPU. + * - When a TD is tearing down, all vCPUs are disassociated from their current + * running CPUs and removed from the per-CPU list during the IPI callback + * running on those CPUs. + * - When a CPU is brought down, traverse the per-CPU list to disassociate all + * associated TD vCPUs and remove them from the per-CPU list. + */ +static DEFINE_PER_CPU(struct list_head, associated_tdvcpus); + +static __always_inline unsigned long tdvmcall_exit_type(struct kvm_vcpu *vcpu) +{ + return to_tdx(vcpu)->vp_enter_args.r10; +} + +static __always_inline unsigned long tdvmcall_leaf(struct kvm_vcpu *vcpu) +{ + return to_tdx(vcpu)->vp_enter_args.r11; +} + +static __always_inline void tdvmcall_set_return_code(struct kvm_vcpu *vcpu, + long val) +{ + to_tdx(vcpu)->vp_enter_args.r10 = val; +} + +static __always_inline void tdvmcall_set_return_val(struct kvm_vcpu *vcpu, + unsigned long val) +{ + to_tdx(vcpu)->vp_enter_args.r11 = val; +} + +static inline void tdx_hkid_free(struct kvm_tdx *kvm_tdx) +{ + tdx_guest_keyid_free(kvm_tdx->hkid); + kvm_tdx->hkid = -1; + atomic_dec(&nr_configured_hkid); + misc_cg_uncharge(MISC_CG_RES_TDX, kvm_tdx->misc_cg, 1); + put_misc_cg(kvm_tdx->misc_cg); + kvm_tdx->misc_cg = NULL; +} + +static inline bool is_hkid_assigned(struct kvm_tdx *kvm_tdx) +{ + return kvm_tdx->hkid > 0; +} + +static inline void tdx_disassociate_vp(struct kvm_vcpu *vcpu) +{ + lockdep_assert_irqs_disabled(); + + list_del(&to_tdx(vcpu)->cpu_list); + + /* + * Ensure tdx->cpu_list is updated before setting vcpu->cpu to -1, + * otherwise, a different CPU can see vcpu->cpu = -1 and add the vCPU + * to its list before it's deleted from this CPU's list. + */ + smp_wmb(); + + vcpu->cpu = -1; +} + +static void tdx_clear_page(struct page *page) +{ + const void *zero_page = (const void *) page_to_virt(ZERO_PAGE(0)); + void *dest = page_to_virt(page); + unsigned long i; + + /* + * The page could have been poisoned. MOVDIR64B also clears + * the poison bit so the kernel can safely use the page again. + */ + for (i = 0; i < PAGE_SIZE; i += 64) + movdir64b(dest + i, zero_page); + /* + * MOVDIR64B store uses WC buffer. Prevent following memory reads + * from seeing potentially poisoned cache. + */ + __mb(); +} + +static void tdx_no_vcpus_enter_start(struct kvm *kvm) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + + lockdep_assert_held_write(&kvm->mmu_lock); + + WRITE_ONCE(kvm_tdx->wait_for_sept_zap, true); + + kvm_make_all_cpus_request(kvm, KVM_REQ_OUTSIDE_GUEST_MODE); +} + +static void tdx_no_vcpus_enter_stop(struct kvm *kvm) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + + lockdep_assert_held_write(&kvm->mmu_lock); + + WRITE_ONCE(kvm_tdx->wait_for_sept_zap, false); +} + +/* TDH.PHYMEM.PAGE.RECLAIM is allowed only when destroying the TD. */ +static int __tdx_reclaim_page(struct page *page) +{ + u64 err, rcx, rdx, r8; + + err = tdh_phymem_page_reclaim(page, &rcx, &rdx, &r8); + + /* + * No need to check for TDX_OPERAND_BUSY; all TD pages are freed + * before the HKID is released and control pages have also been + * released at this point, so there is no possibility of contention. + */ + if (WARN_ON_ONCE(err)) { + pr_tdx_error_3(TDH_PHYMEM_PAGE_RECLAIM, err, rcx, rdx, r8); + return -EIO; + } + return 0; +} + +static int tdx_reclaim_page(struct page *page) +{ + int r; + + r = __tdx_reclaim_page(page); + if (!r) + tdx_clear_page(page); + return r; +} + + +/* + * Reclaim the TD control page(s) which are crypto-protected by TDX guest's + * private KeyID. Assume the cache associated with the TDX private KeyID has + * been flushed. + */ +static void tdx_reclaim_control_page(struct page *ctrl_page) +{ + /* + * Leak the page if the kernel failed to reclaim the page. + * The kernel cannot use it safely anymore. + */ + if (tdx_reclaim_page(ctrl_page)) + return; + + __free_page(ctrl_page); +} + +struct tdx_flush_vp_arg { + struct kvm_vcpu *vcpu; + u64 err; +}; + +static void tdx_flush_vp(void *_arg) +{ + struct tdx_flush_vp_arg *arg = _arg; + struct kvm_vcpu *vcpu = arg->vcpu; + u64 err; + + arg->err = 0; + lockdep_assert_irqs_disabled(); + + /* Task migration can race with CPU offlining. */ + if (unlikely(vcpu->cpu != raw_smp_processor_id())) + return; + + /* + * No need to do TDH_VP_FLUSH if the vCPU hasn't been initialized. The + * list tracking still needs to be updated so that it's correct if/when + * the vCPU does get initialized. + */ + if (to_tdx(vcpu)->state != VCPU_TD_STATE_UNINITIALIZED) { + /* + * No need to retry. TDX Resources needed for TDH.VP.FLUSH are: + * TDVPR as exclusive, TDR as shared, and TDCS as shared. This + * vp flush function is called when destructing vCPU/TD or vCPU + * migration. No other thread uses TDVPR in those cases. + */ + err = tdh_vp_flush(&to_tdx(vcpu)->vp); + if (unlikely(err && err != TDX_VCPU_NOT_ASSOCIATED)) { + /* + * This function is called in IPI context. Do not use + * printk to avoid console semaphore. + * The caller prints out the error message, instead. + */ + if (err) + arg->err = err; + } + } + + tdx_disassociate_vp(vcpu); +} + +static void tdx_flush_vp_on_cpu(struct kvm_vcpu *vcpu) +{ + struct tdx_flush_vp_arg arg = { + .vcpu = vcpu, + }; + int cpu = vcpu->cpu; + + if (unlikely(cpu == -1)) + return; + + smp_call_function_single(cpu, tdx_flush_vp, &arg, 1); + if (KVM_BUG_ON(arg.err, vcpu->kvm)) + pr_tdx_error(TDH_VP_FLUSH, arg.err); +} + +void tdx_disable_virtualization_cpu(void) +{ + int cpu = raw_smp_processor_id(); + struct list_head *tdvcpus = &per_cpu(associated_tdvcpus, cpu); + struct tdx_flush_vp_arg arg; + struct vcpu_tdx *tdx, *tmp; + unsigned long flags; + + local_irq_save(flags); + /* Safe variant needed as tdx_disassociate_vp() deletes the entry. */ + list_for_each_entry_safe(tdx, tmp, tdvcpus, cpu_list) { + arg.vcpu = &tdx->vcpu; + tdx_flush_vp(&arg); + } + local_irq_restore(flags); +} + +#define TDX_SEAMCALL_RETRIES 10000 + +static void smp_func_do_phymem_cache_wb(void *unused) +{ + u64 err = 0; + bool resume; + int i; + + /* + * TDH.PHYMEM.CACHE.WB flushes caches associated with any TDX private + * KeyID on the package or core. The TDX module may not finish the + * cache flush but return TDX_INTERRUPTED_RESUMEABLE instead. The + * kernel should retry it until it returns success w/o rescheduling. + */ + for (i = TDX_SEAMCALL_RETRIES; i > 0; i--) { + resume = !!err; + err = tdh_phymem_cache_wb(resume); + switch (err) { + case TDX_INTERRUPTED_RESUMABLE: + continue; + case TDX_NO_HKID_READY_TO_WBCACHE: + err = TDX_SUCCESS; /* Already done by other thread */ + fallthrough; + default: + goto out; + } + } + +out: + if (WARN_ON_ONCE(err)) + pr_tdx_error(TDH_PHYMEM_CACHE_WB, err); +} + +void tdx_mmu_release_hkid(struct kvm *kvm) +{ + bool packages_allocated, targets_allocated; + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + cpumask_var_t packages, targets; + struct kvm_vcpu *vcpu; + unsigned long j; + int i; + u64 err; + + if (!is_hkid_assigned(kvm_tdx)) + return; + + packages_allocated = zalloc_cpumask_var(&packages, GFP_KERNEL); + targets_allocated = zalloc_cpumask_var(&targets, GFP_KERNEL); + cpus_read_lock(); + + kvm_for_each_vcpu(j, vcpu, kvm) + tdx_flush_vp_on_cpu(vcpu); + + /* + * TDH.PHYMEM.CACHE.WB tries to acquire the TDX module global lock + * and can fail with TDX_OPERAND_BUSY when it fails to get the lock. + * Multiple TDX guests can be destroyed simultaneously. Take the + * mutex to prevent it from getting error. + */ + mutex_lock(&tdx_lock); + + /* + * Releasing HKID is in vm_destroy(). + * After the above flushing vps, there should be no more vCPU + * associations, as all vCPU fds have been released at this stage. + */ + err = tdh_mng_vpflushdone(&kvm_tdx->td); + if (err == TDX_FLUSHVP_NOT_DONE) + goto out; + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error(TDH_MNG_VPFLUSHDONE, err); + pr_err("tdh_mng_vpflushdone() failed. HKID %d is leaked.\n", + kvm_tdx->hkid); + goto out; + } + + for_each_online_cpu(i) { + if (packages_allocated && + cpumask_test_and_set_cpu(topology_physical_package_id(i), + packages)) + continue; + if (targets_allocated) + cpumask_set_cpu(i, targets); + } + if (targets_allocated) + on_each_cpu_mask(targets, smp_func_do_phymem_cache_wb, NULL, true); + else + on_each_cpu(smp_func_do_phymem_cache_wb, NULL, true); + /* + * In the case of error in smp_func_do_phymem_cache_wb(), the following + * tdh_mng_key_freeid() will fail. + */ + err = tdh_mng_key_freeid(&kvm_tdx->td); + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error(TDH_MNG_KEY_FREEID, err); + pr_err("tdh_mng_key_freeid() failed. HKID %d is leaked.\n", + kvm_tdx->hkid); + } else { + tdx_hkid_free(kvm_tdx); + } + +out: + mutex_unlock(&tdx_lock); + cpus_read_unlock(); + free_cpumask_var(targets); + free_cpumask_var(packages); +} + +static void tdx_reclaim_td_control_pages(struct kvm *kvm) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + u64 err; + int i; + + /* + * tdx_mmu_release_hkid() failed to reclaim HKID. Something went wrong + * heavily with TDX module. Give up freeing TD pages. As the function + * already warned, don't warn it again. + */ + if (is_hkid_assigned(kvm_tdx)) + return; + + if (kvm_tdx->td.tdcs_pages) { + for (i = 0; i < kvm_tdx->td.tdcs_nr_pages; i++) { + if (!kvm_tdx->td.tdcs_pages[i]) + continue; + + tdx_reclaim_control_page(kvm_tdx->td.tdcs_pages[i]); + } + kfree(kvm_tdx->td.tdcs_pages); + kvm_tdx->td.tdcs_pages = NULL; + } + + if (!kvm_tdx->td.tdr_page) + return; + + if (__tdx_reclaim_page(kvm_tdx->td.tdr_page)) + return; + + /* + * Use a SEAMCALL to ask the TDX module to flush the cache based on the + * KeyID. TDX module may access TDR while operating on TD (Especially + * when it is reclaiming TDCS). + */ + err = tdh_phymem_page_wbinvd_tdr(&kvm_tdx->td); + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err); + return; + } + tdx_clear_page(kvm_tdx->td.tdr_page); + + __free_page(kvm_tdx->td.tdr_page); + kvm_tdx->td.tdr_page = NULL; +} + +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) +{ + struct kvm_tdx *kvm_tdx = param; + u64 err; + + /* TDX_RND_NO_ENTROPY related retries are handled by sc_retry() */ + err = tdh_mng_key_config(&kvm_tdx->td); + + if (KVM_BUG_ON(err, &kvm_tdx->kvm)) { + pr_tdx_error(TDH_MNG_KEY_CONFIG, err); + return -EIO; + } + + return 0; +} + +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; + kvm->arch.disabled_quirks |= KVM_X86_QUIRK_IGNORE_GUEST_PAT; + + /* + * Because guest TD is protected, VMM can't parse the instruction in TD. + * Instead, guest uses MMIO hypercall. For unmodified device driver, + * #VE needs to be injected for MMIO and #VE handler in TD converts MMIO + * instruction into MMIO hypercall. + * + * SPTE value for MMIO needs to be setup so that #VE is injected into + * TD instead of triggering EPT MISCONFIG. + * - RWX=0 so that EPT violation is triggered. + * - suppress #VE bit is cleared to inject #VE. + */ + kvm_mmu_set_mmio_spte_value(kvm, 0); + + /* + * TDX has its own limit of maximum vCPUs it can support for all + * TDX guests in addition to KVM_MAX_VCPUS. TDX module reports + * such limit via the MAX_VCPU_PER_TD global metadata. In + * practice, it reflects the number of logical CPUs that ALL + * platforms that the TDX module supports can possibly have. + * + * Limit TDX guest's maximum vCPUs to the number of logical CPUs + * the platform has. Simply forwarding the MAX_VCPU_PER_TD to + * userspace would result in an unpredictable ABI. + */ + kvm->max_vcpus = min_t(int, kvm->max_vcpus, num_present_cpus()); + + kvm_tdx->state = TD_STATE_UNINITIALIZED; + + return 0; +} + +int tdx_vcpu_create(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + struct vcpu_tdx *tdx = to_tdx(vcpu); + + if (kvm_tdx->state != TD_STATE_INITIALIZED) + return -EIO; + + /* + * TDX module mandates APICv, which requires an in-kernel local APIC. + * Disallow an in-kernel I/O APIC, because level-triggered interrupts + * and thus the I/O APIC as a whole can't be faithfully emulated in KVM. + */ + if (!irqchip_split(vcpu->kvm)) + return -EINVAL; + + fpstate_set_confidential(&vcpu->arch.guest_fpu); + vcpu->arch.apic->guest_apic_protected = true; + INIT_LIST_HEAD(&tdx->vt.pi_wakeup_list); + + vcpu->arch.efer = EFER_SCE | EFER_LME | EFER_LMA | EFER_NX; + + vcpu->arch.switch_db_regs = KVM_DEBUGREG_AUTO_SWITCH; + vcpu->arch.cr0_guest_owned_bits = -1ul; + vcpu->arch.cr4_guest_owned_bits = -1ul; + + /* KVM can't change TSC offset/multiplier as TDX module manages them. */ + vcpu->arch.guest_tsc_protected = true; + vcpu->arch.tsc_offset = kvm_tdx->tsc_offset; + vcpu->arch.l1_tsc_offset = vcpu->arch.tsc_offset; + vcpu->arch.tsc_scaling_ratio = kvm_tdx->tsc_multiplier; + vcpu->arch.l1_tsc_scaling_ratio = kvm_tdx->tsc_multiplier; + + vcpu->arch.guest_state_protected = + !(to_kvm_tdx(vcpu->kvm)->attributes & TDX_TD_ATTR_DEBUG); + + if ((kvm_tdx->xfam & XFEATURE_MASK_XTILE) == XFEATURE_MASK_XTILE) + vcpu->arch.xfd_no_write_intercept = true; + + tdx->vt.pi_desc.nv = POSTED_INTR_VECTOR; + __pi_set_sn(&tdx->vt.pi_desc); + + tdx->state = VCPU_TD_STATE_UNINITIALIZED; + + return 0; +} + +void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + + vmx_vcpu_pi_load(vcpu, cpu); + if (vcpu->cpu == cpu || !is_hkid_assigned(to_kvm_tdx(vcpu->kvm))) + return; + + tdx_flush_vp_on_cpu(vcpu); + + KVM_BUG_ON(cpu != raw_smp_processor_id(), vcpu->kvm); + local_irq_disable(); + /* + * Pairs with the smp_wmb() in tdx_disassociate_vp() to ensure + * vcpu->cpu is read before tdx->cpu_list. + */ + smp_rmb(); + + list_add(&tdx->cpu_list, &per_cpu(associated_tdvcpus, cpu)); + local_irq_enable(); +} + +bool tdx_interrupt_allowed(struct kvm_vcpu *vcpu) +{ + /* + * KVM can't get the interrupt status of TDX guest and it assumes + * interrupt is always allowed unless TDX guest calls TDVMCALL with HLT, + * which passes the interrupt blocked flag. + */ + return vmx_get_exit_reason(vcpu).basic != EXIT_REASON_HLT || + !to_tdx(vcpu)->vp_enter_args.r12; +} + +bool tdx_protected_apic_has_interrupt(struct kvm_vcpu *vcpu) +{ + u64 vcpu_state_details; + + if (pi_has_pending_interrupt(vcpu)) + return true; + + /* + * Only check RVI pending for HALTED case with IRQ enabled. + * For non-HLT cases, KVM doesn't care about STI/SS shadows. And if the + * interrupt was pending before TD exit, then it _must_ be blocked, + * otherwise the interrupt would have been serviced at the instruction + * boundary. + */ + if (vmx_get_exit_reason(vcpu).basic != EXIT_REASON_HLT || + to_tdx(vcpu)->vp_enter_args.r12) + return false; + + vcpu_state_details = + td_state_non_arch_read64(to_tdx(vcpu), TD_VCPU_STATE_DETAILS_NON_ARCH); + + return tdx_vcpu_state_details_intr_pending(vcpu_state_details); +} + +/* + * Compared to vmx_prepare_switch_to_guest(), there is not much to do + * as SEAMCALL/SEAMRET calls take care of most of save and restore. + */ +void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu) +{ + struct vcpu_vt *vt = to_vt(vcpu); + + if (vt->guest_state_loaded) + return; + + if (likely(is_64bit_mm(current->mm))) + vt->msr_host_kernel_gs_base = current->thread.gsbase; + else + vt->msr_host_kernel_gs_base = read_msr(MSR_KERNEL_GS_BASE); + + vt->host_debugctlmsr = get_debugctlmsr(); + + vt->guest_state_loaded = true; +} + +struct tdx_uret_msr { + u32 msr; + unsigned int slot; + u64 defval; +}; + +static struct tdx_uret_msr tdx_uret_msrs[] = { + {.msr = MSR_SYSCALL_MASK, .defval = 0x20200 }, + {.msr = MSR_STAR,}, + {.msr = MSR_LSTAR,}, + {.msr = MSR_TSC_AUX,}, +}; + +static void tdx_user_return_msr_update_cache(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(tdx_uret_msrs); i++) + kvm_user_return_msr_update_cache(tdx_uret_msrs[i].slot, + tdx_uret_msrs[i].defval); +} + +static void tdx_prepare_switch_to_host(struct kvm_vcpu *vcpu) +{ + struct vcpu_vt *vt = to_vt(vcpu); + struct vcpu_tdx *tdx = to_tdx(vcpu); + + if (!vt->guest_state_loaded) + return; + + ++vcpu->stat.host_state_reload; + wrmsrl(MSR_KERNEL_GS_BASE, vt->msr_host_kernel_gs_base); + + if (tdx->guest_entered) { + tdx_user_return_msr_update_cache(); + tdx->guest_entered = false; + } + + vt->guest_state_loaded = false; +} + +void tdx_vcpu_put(struct kvm_vcpu *vcpu) +{ + vmx_vcpu_pi_put(vcpu); + tdx_prepare_switch_to_host(vcpu); +} + +void tdx_vcpu_free(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + struct vcpu_tdx *tdx = to_tdx(vcpu); + int i; + + /* + * It is not possible to reclaim pages while hkid is assigned. It might + * be assigned if: + * 1. the TD VM is being destroyed but freeing hkid failed, in which + * case the pages are leaked + * 2. TD VCPU creation failed and this on the error path, in which case + * there is nothing to do anyway + */ + if (is_hkid_assigned(kvm_tdx)) + return; + + if (tdx->vp.tdcx_pages) { + for (i = 0; i < kvm_tdx->td.tdcx_nr_pages; i++) { + if (tdx->vp.tdcx_pages[i]) + tdx_reclaim_control_page(tdx->vp.tdcx_pages[i]); + } + kfree(tdx->vp.tdcx_pages); + tdx->vp.tdcx_pages = NULL; + } + if (tdx->vp.tdvpr_page) { + tdx_reclaim_control_page(tdx->vp.tdvpr_page); + tdx->vp.tdvpr_page = 0; + } + + tdx->state = VCPU_TD_STATE_UNINITIALIZED; +} + +int tdx_vcpu_pre_run(struct kvm_vcpu *vcpu) +{ + if (unlikely(to_tdx(vcpu)->state != VCPU_TD_STATE_INITIALIZED || + to_kvm_tdx(vcpu->kvm)->state != TD_STATE_RUNNABLE)) + return -EINVAL; + + return 1; +} + +static __always_inline u32 tdcall_to_vmx_exit_reason(struct kvm_vcpu *vcpu) +{ + switch (tdvmcall_leaf(vcpu)) { + case EXIT_REASON_CPUID: + case EXIT_REASON_HLT: + case EXIT_REASON_IO_INSTRUCTION: + case EXIT_REASON_MSR_READ: + case EXIT_REASON_MSR_WRITE: + return tdvmcall_leaf(vcpu); + case EXIT_REASON_EPT_VIOLATION: + return EXIT_REASON_EPT_MISCONFIG; + default: + break; + } + + return EXIT_REASON_TDCALL; +} + +static __always_inline u32 tdx_to_vmx_exit_reason(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + u32 exit_reason; + + switch (tdx->vp_enter_ret & TDX_SEAMCALL_STATUS_MASK) { + case TDX_SUCCESS: + case TDX_NON_RECOVERABLE_VCPU: + case TDX_NON_RECOVERABLE_TD: + case TDX_NON_RECOVERABLE_TD_NON_ACCESSIBLE: + case TDX_NON_RECOVERABLE_TD_WRONG_APIC_MODE: + break; + default: + return -1u; + } + + exit_reason = tdx->vp_enter_ret; + + switch (exit_reason) { + case EXIT_REASON_TDCALL: + if (tdvmcall_exit_type(vcpu)) + return EXIT_REASON_VMCALL; + + return tdcall_to_vmx_exit_reason(vcpu); + case EXIT_REASON_EPT_MISCONFIG: + /* + * Defer KVM_BUG_ON() until tdx_handle_exit() because this is in + * non-instrumentable code with interrupts disabled. + */ + return -1u; + default: + break; + } + + return exit_reason; +} + +static noinstr void tdx_vcpu_enter_exit(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + struct vcpu_vt *vt = to_vt(vcpu); + + guest_state_enter_irqoff(); + + tdx->vp_enter_ret = tdh_vp_enter(&tdx->vp, &tdx->vp_enter_args); + + vt->exit_reason.full = tdx_to_vmx_exit_reason(vcpu); + + vt->exit_qualification = tdx->vp_enter_args.rcx; + tdx->ext_exit_qualification = tdx->vp_enter_args.rdx; + tdx->exit_gpa = tdx->vp_enter_args.r8; + vt->exit_intr_info = tdx->vp_enter_args.r9; + + vmx_handle_nmi(vcpu); + + guest_state_exit_irqoff(); +} + +static bool tdx_failed_vmentry(struct kvm_vcpu *vcpu) +{ + return vmx_get_exit_reason(vcpu).failed_vmentry && + vmx_get_exit_reason(vcpu).full != -1u; +} + +static fastpath_t tdx_exit_handlers_fastpath(struct kvm_vcpu *vcpu) +{ + u64 vp_enter_ret = to_tdx(vcpu)->vp_enter_ret; + + /* + * TDX_OPERAND_BUSY could be returned for SEPT due to 0-step mitigation + * or for TD EPOCH due to contention with TDH.MEM.TRACK on TDH.VP.ENTER. + * + * When KVM requests KVM_REQ_OUTSIDE_GUEST_MODE, which has both + * KVM_REQUEST_WAIT and KVM_REQUEST_NO_ACTION set, it requires target + * vCPUs leaving fastpath so that interrupt can be enabled to ensure the + * IPIs can be delivered. Return EXIT_FASTPATH_EXIT_HANDLED instead of + * EXIT_FASTPATH_REENTER_GUEST to exit fastpath, otherwise, the + * requester may be blocked endlessly. + */ + if (unlikely(tdx_operand_busy(vp_enter_ret))) + return EXIT_FASTPATH_EXIT_HANDLED; + + return EXIT_FASTPATH_NONE; +} + +#define TDX_REGS_AVAIL_SET (BIT_ULL(VCPU_EXREG_EXIT_INFO_1) | \ + BIT_ULL(VCPU_EXREG_EXIT_INFO_2) | \ + BIT_ULL(VCPU_REGS_RAX) | \ + BIT_ULL(VCPU_REGS_RBX) | \ + BIT_ULL(VCPU_REGS_RCX) | \ + BIT_ULL(VCPU_REGS_RDX) | \ + BIT_ULL(VCPU_REGS_RBP) | \ + BIT_ULL(VCPU_REGS_RSI) | \ + BIT_ULL(VCPU_REGS_RDI) | \ + BIT_ULL(VCPU_REGS_R8) | \ + BIT_ULL(VCPU_REGS_R9) | \ + BIT_ULL(VCPU_REGS_R10) | \ + BIT_ULL(VCPU_REGS_R11) | \ + BIT_ULL(VCPU_REGS_R12) | \ + BIT_ULL(VCPU_REGS_R13) | \ + BIT_ULL(VCPU_REGS_R14) | \ + BIT_ULL(VCPU_REGS_R15)) + +static void tdx_load_host_xsave_state(struct kvm_vcpu *vcpu) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + + /* + * All TDX hosts support PKRU; but even if they didn't, + * vcpu->arch.host_pkru would be 0 and the wrpkru would be + * skipped. + */ + if (vcpu->arch.host_pkru != 0) + wrpkru(vcpu->arch.host_pkru); + + if (kvm_host.xcr0 != (kvm_tdx->xfam & kvm_caps.supported_xcr0)) + xsetbv(XCR_XFEATURE_ENABLED_MASK, kvm_host.xcr0); + + /* + * Likewise, even if a TDX hosts didn't support XSS both arms of + * the comparison would be 0 and the wrmsrl would be skipped. + */ + if (kvm_host.xss != (kvm_tdx->xfam & kvm_caps.supported_xss)) + wrmsrl(MSR_IA32_XSS, kvm_host.xss); +} + +#define TDX_DEBUGCTL_PRESERVED (DEBUGCTLMSR_BTF | \ + DEBUGCTLMSR_FREEZE_PERFMON_ON_PMI | \ + DEBUGCTLMSR_FREEZE_IN_SMM) + +fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + struct vcpu_vt *vt = to_vt(vcpu); + + /* + * force_immediate_exit requires vCPU entering for events injection with + * an immediately exit followed. But The TDX module doesn't guarantee + * entry, it's already possible for KVM to _think_ it completely entry + * to the guest without actually having done so. + * Since KVM never needs to force an immediate exit for TDX, and can't + * do direct injection, just warn on force_immediate_exit. + */ + WARN_ON_ONCE(force_immediate_exit); + + /* + * Wait until retry of SEPT-zap-related SEAMCALL completes before + * allowing vCPU entry to avoid contention with tdh_vp_enter() and + * TDCALLs. + */ + if (unlikely(READ_ONCE(to_kvm_tdx(vcpu->kvm)->wait_for_sept_zap))) + return EXIT_FASTPATH_EXIT_HANDLED; + + trace_kvm_entry(vcpu, force_immediate_exit); + + if (pi_test_on(&vt->pi_desc)) { + apic->send_IPI_self(POSTED_INTR_VECTOR); + + if (pi_test_pir(kvm_lapic_get_reg(vcpu->arch.apic, APIC_LVTT) & + APIC_VECTOR_MASK, &vt->pi_desc)) + kvm_wait_lapic_expire(vcpu); + } + + tdx_vcpu_enter_exit(vcpu); + + if (vt->host_debugctlmsr & ~TDX_DEBUGCTL_PRESERVED) + update_debugctlmsr(vt->host_debugctlmsr); + + tdx_load_host_xsave_state(vcpu); + tdx->guest_entered = true; + + vcpu->arch.regs_avail &= TDX_REGS_AVAIL_SET; + + if (unlikely(tdx->vp_enter_ret == EXIT_REASON_EPT_MISCONFIG)) + return EXIT_FASTPATH_NONE; + + if (unlikely((tdx->vp_enter_ret & TDX_SW_ERROR) == TDX_SW_ERROR)) + return EXIT_FASTPATH_NONE; + + if (unlikely(vmx_get_exit_reason(vcpu).basic == EXIT_REASON_MCE_DURING_VMENTRY)) + kvm_machine_check(); + + trace_kvm_exit(vcpu, KVM_ISA_VMX); + + if (unlikely(tdx_failed_vmentry(vcpu))) + return EXIT_FASTPATH_NONE; + + return tdx_exit_handlers_fastpath(vcpu); +} + +void tdx_inject_nmi(struct kvm_vcpu *vcpu) +{ + ++vcpu->stat.nmi_injections; + td_management_write8(to_tdx(vcpu), TD_VCPU_PEND_NMI, 1); + /* + * From KVM's perspective, NMI injection is completed right after + * writing to PEND_NMI. KVM doesn't care whether an NMI is injected by + * the TDX module or not. + */ + vcpu->arch.nmi_injected = false; + /* + * TDX doesn't support KVM to request NMI window exit. If there is + * still a pending vNMI, KVM is not able to inject it along with the + * one pending in TDX module in a back-to-back way. Since the previous + * vNMI is still pending in TDX module, i.e. it has not been delivered + * to TDX guest yet, it's OK to collapse the pending vNMI into the + * previous one. The guest is expected to handle all the NMI sources + * when handling the first vNMI. + */ + vcpu->arch.nmi_pending = 0; +} + +static int tdx_handle_exception_nmi(struct kvm_vcpu *vcpu) +{ + u32 intr_info = vmx_get_intr_info(vcpu); + + /* + * Machine checks are handled by handle_exception_irqoff(), or by + * tdx_handle_exit() with TDX_NON_RECOVERABLE set if a #MC occurs on + * VM-Entry. NMIs are handled by tdx_vcpu_enter_exit(). + */ + if (is_nmi(intr_info) || is_machine_check(intr_info)) + return 1; + + vcpu->run->exit_reason = KVM_EXIT_EXCEPTION; + vcpu->run->ex.exception = intr_info & INTR_INFO_VECTOR_MASK; + vcpu->run->ex.error_code = 0; + + return 0; +} + +static int complete_hypercall_exit(struct kvm_vcpu *vcpu) +{ + tdvmcall_set_return_code(vcpu, vcpu->run->hypercall.ret); + return 1; +} + +static int tdx_emulate_vmcall(struct kvm_vcpu *vcpu) +{ + kvm_rax_write(vcpu, to_tdx(vcpu)->vp_enter_args.r10); + kvm_rbx_write(vcpu, to_tdx(vcpu)->vp_enter_args.r11); + kvm_rcx_write(vcpu, to_tdx(vcpu)->vp_enter_args.r12); + kvm_rdx_write(vcpu, to_tdx(vcpu)->vp_enter_args.r13); + kvm_rsi_write(vcpu, to_tdx(vcpu)->vp_enter_args.r14); + + return __kvm_emulate_hypercall(vcpu, 0, complete_hypercall_exit); +} + +/* + * Split into chunks and check interrupt pending between chunks. This allows + * for timely injection of interrupts to prevent issues with guest lockup + * detection. + */ +#define TDX_MAP_GPA_MAX_LEN (2 * 1024 * 1024) +static void __tdx_map_gpa(struct vcpu_tdx *tdx); + +static int tdx_complete_vmcall_map_gpa(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + + if (vcpu->run->hypercall.ret) { + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND); + tdx->vp_enter_args.r11 = tdx->map_gpa_next; + return 1; + } + + tdx->map_gpa_next += TDX_MAP_GPA_MAX_LEN; + if (tdx->map_gpa_next >= tdx->map_gpa_end) + return 1; + + /* + * Stop processing the remaining part if there is a pending interrupt, + * which could be qualified to deliver. Skip checking pending RVI for + * TDVMCALL_MAP_GPA, see comments in tdx_protected_apic_has_interrupt(). + */ + if (kvm_vcpu_has_events(vcpu)) { + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_RETRY); + tdx->vp_enter_args.r11 = tdx->map_gpa_next; + return 1; + } + + __tdx_map_gpa(tdx); + return 0; +} + +static void __tdx_map_gpa(struct vcpu_tdx *tdx) +{ + u64 gpa = tdx->map_gpa_next; + u64 size = tdx->map_gpa_end - tdx->map_gpa_next; + + if (size > TDX_MAP_GPA_MAX_LEN) + size = TDX_MAP_GPA_MAX_LEN; + + tdx->vcpu.run->exit_reason = KVM_EXIT_HYPERCALL; + tdx->vcpu.run->hypercall.nr = KVM_HC_MAP_GPA_RANGE; + /* + * In principle this should have been -KVM_ENOSYS, but userspace (QEMU <=9.2) + * assumed that vcpu->run->hypercall.ret is never changed by KVM and thus that + * it was always zero on KVM_EXIT_HYPERCALL. Since KVM is now overwriting + * vcpu->run->hypercall.ret, ensuring that it is zero to not break QEMU. + */ + tdx->vcpu.run->hypercall.ret = 0; + tdx->vcpu.run->hypercall.args[0] = gpa & ~gfn_to_gpa(kvm_gfn_direct_bits(tdx->vcpu.kvm)); + tdx->vcpu.run->hypercall.args[1] = size / PAGE_SIZE; + tdx->vcpu.run->hypercall.args[2] = vt_is_tdx_private_gpa(tdx->vcpu.kvm, gpa) ? + KVM_MAP_GPA_RANGE_ENCRYPTED : + KVM_MAP_GPA_RANGE_DECRYPTED; + tdx->vcpu.run->hypercall.flags = KVM_EXIT_HYPERCALL_LONG_MODE; + + tdx->vcpu.arch.complete_userspace_io = tdx_complete_vmcall_map_gpa; +} + +static int tdx_map_gpa(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + u64 gpa = tdx->vp_enter_args.r12; + u64 size = tdx->vp_enter_args.r13; + u64 ret; + + /* + * Converting TDVMCALL_MAP_GPA to KVM_HC_MAP_GPA_RANGE requires + * userspace to enable KVM_CAP_EXIT_HYPERCALL with KVM_HC_MAP_GPA_RANGE + * bit set. If not, the error code is not defined in GHCI for TDX, use + * TDVMCALL_STATUS_INVALID_OPERAND for this case. + */ + if (!user_exit_on_hypercall(vcpu->kvm, KVM_HC_MAP_GPA_RANGE)) { + ret = TDVMCALL_STATUS_INVALID_OPERAND; + goto error; + } + + if (gpa + size <= gpa || !kvm_vcpu_is_legal_gpa(vcpu, gpa) || + !kvm_vcpu_is_legal_gpa(vcpu, gpa + size - 1) || + (vt_is_tdx_private_gpa(vcpu->kvm, gpa) != + vt_is_tdx_private_gpa(vcpu->kvm, gpa + size - 1))) { + ret = TDVMCALL_STATUS_INVALID_OPERAND; + goto error; + } + + if (!PAGE_ALIGNED(gpa) || !PAGE_ALIGNED(size)) { + ret = TDVMCALL_STATUS_ALIGN_ERROR; + goto error; + } + + tdx->map_gpa_end = gpa + size; + tdx->map_gpa_next = gpa; + + __tdx_map_gpa(tdx); + return 0; + +error: + tdvmcall_set_return_code(vcpu, ret); + tdx->vp_enter_args.r11 = gpa; + return 1; +} + +static int tdx_report_fatal_error(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + u64 *regs = vcpu->run->system_event.data; + u64 *module_regs = &tdx->vp_enter_args.r8; + int index = VCPU_REGS_RAX; + + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; + vcpu->run->system_event.type = KVM_SYSTEM_EVENT_TDX_FATAL; + vcpu->run->system_event.ndata = 16; + + /* Dump 16 general-purpose registers to userspace in ascending order. */ + regs[index++] = tdx->vp_enter_ret; + regs[index++] = tdx->vp_enter_args.rcx; + regs[index++] = tdx->vp_enter_args.rdx; + regs[index++] = tdx->vp_enter_args.rbx; + regs[index++] = 0; + regs[index++] = 0; + regs[index++] = tdx->vp_enter_args.rsi; + regs[index] = tdx->vp_enter_args.rdi; + for (index = 0; index < 8; index++) + regs[VCPU_REGS_R8 + index] = module_regs[index]; + + return 0; +} + +static int tdx_emulate_cpuid(struct kvm_vcpu *vcpu) +{ + u32 eax, ebx, ecx, edx; + struct vcpu_tdx *tdx = to_tdx(vcpu); + + /* EAX and ECX for cpuid is stored in R12 and R13. */ + eax = tdx->vp_enter_args.r12; + ecx = tdx->vp_enter_args.r13; + + kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, false); + + tdx->vp_enter_args.r12 = eax; + tdx->vp_enter_args.r13 = ebx; + tdx->vp_enter_args.r14 = ecx; + tdx->vp_enter_args.r15 = edx; + + return 1; +} + +static int tdx_complete_pio_out(struct kvm_vcpu *vcpu) +{ + vcpu->arch.pio.count = 0; + return 1; +} + +static int tdx_complete_pio_in(struct kvm_vcpu *vcpu) +{ + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; + unsigned long val = 0; + int ret; + + ret = ctxt->ops->pio_in_emulated(ctxt, vcpu->arch.pio.size, + vcpu->arch.pio.port, &val, 1); + + WARN_ON_ONCE(!ret); + + tdvmcall_set_return_val(vcpu, val); + + return 1; +} + +static int tdx_emulate_io(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; + unsigned long val = 0; + unsigned int port; + u64 size, write; + int ret; + + ++vcpu->stat.io_exits; + + size = tdx->vp_enter_args.r12; + write = tdx->vp_enter_args.r13; + port = tdx->vp_enter_args.r14; + + if ((write != 0 && write != 1) || (size != 1 && size != 2 && size != 4)) { + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND); + return 1; + } + + if (write) { + val = tdx->vp_enter_args.r15; + ret = ctxt->ops->pio_out_emulated(ctxt, size, port, &val, 1); + } else { + ret = ctxt->ops->pio_in_emulated(ctxt, size, port, &val, 1); + } + + if (!ret) + vcpu->arch.complete_userspace_io = write ? tdx_complete_pio_out : + tdx_complete_pio_in; + else if (!write) + tdvmcall_set_return_val(vcpu, val); + + return ret; +} + +static int tdx_complete_mmio_read(struct kvm_vcpu *vcpu) +{ + unsigned long val = 0; + gpa_t gpa; + int size; + + gpa = vcpu->mmio_fragments[0].gpa; + size = vcpu->mmio_fragments[0].len; + + memcpy(&val, vcpu->run->mmio.data, size); + tdvmcall_set_return_val(vcpu, val); + trace_kvm_mmio(KVM_TRACE_MMIO_READ, size, gpa, &val); + return 1; +} + +static inline int tdx_mmio_write(struct kvm_vcpu *vcpu, gpa_t gpa, int size, + unsigned long val) +{ + if (!kvm_io_bus_write(vcpu, KVM_FAST_MMIO_BUS, gpa, 0, NULL)) { + trace_kvm_fast_mmio(gpa); + return 0; + } + + trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, size, gpa, &val); + if (kvm_io_bus_write(vcpu, KVM_MMIO_BUS, gpa, size, &val)) + return -EOPNOTSUPP; + + return 0; +} + +static inline int tdx_mmio_read(struct kvm_vcpu *vcpu, gpa_t gpa, int size) +{ + unsigned long val; + + if (kvm_io_bus_read(vcpu, KVM_MMIO_BUS, gpa, size, &val)) + return -EOPNOTSUPP; + + tdvmcall_set_return_val(vcpu, val); + trace_kvm_mmio(KVM_TRACE_MMIO_READ, size, gpa, &val); + return 0; +} + +static int tdx_emulate_mmio(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + int size, write, r; + unsigned long val; + gpa_t gpa; + + size = tdx->vp_enter_args.r12; + write = tdx->vp_enter_args.r13; + gpa = tdx->vp_enter_args.r14; + val = write ? tdx->vp_enter_args.r15 : 0; + + if (size != 1 && size != 2 && size != 4 && size != 8) + goto error; + if (write != 0 && write != 1) + goto error; + + /* + * TDG.VP.VMCALL<MMIO> allows only shared GPA, it makes no sense to + * do MMIO emulation for private GPA. + */ + if (vt_is_tdx_private_gpa(vcpu->kvm, gpa) || + vt_is_tdx_private_gpa(vcpu->kvm, gpa + size - 1)) + goto error; + + gpa = gpa & ~gfn_to_gpa(kvm_gfn_direct_bits(vcpu->kvm)); + + if (write) + r = tdx_mmio_write(vcpu, gpa, size, val); + else + r = tdx_mmio_read(vcpu, gpa, size); + if (!r) + /* Kernel completed device emulation. */ + return 1; + + /* Request the device emulation to userspace device model. */ + vcpu->mmio_is_write = write; + if (!write) + vcpu->arch.complete_userspace_io = tdx_complete_mmio_read; + + vcpu->run->mmio.phys_addr = gpa; + vcpu->run->mmio.len = size; + vcpu->run->mmio.is_write = write; + vcpu->run->exit_reason = KVM_EXIT_MMIO; + + if (write) { + memcpy(vcpu->run->mmio.data, &val, size); + } else { + vcpu->mmio_fragments[0].gpa = gpa; + vcpu->mmio_fragments[0].len = size; + trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, size, gpa, NULL); + } + return 0; + +error: + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND); + return 1; +} + +static int tdx_get_td_vm_call_info(struct kvm_vcpu *vcpu) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + + if (tdx->vp_enter_args.r12) + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND); + else { + tdx->vp_enter_args.r11 = 0; + tdx->vp_enter_args.r13 = 0; + tdx->vp_enter_args.r14 = 0; + } + return 1; +} + +static int handle_tdvmcall(struct kvm_vcpu *vcpu) +{ + switch (tdvmcall_leaf(vcpu)) { + case TDVMCALL_MAP_GPA: + return tdx_map_gpa(vcpu); + case TDVMCALL_REPORT_FATAL_ERROR: + return tdx_report_fatal_error(vcpu); + case TDVMCALL_GET_TD_VM_CALL_INFO: + return tdx_get_td_vm_call_info(vcpu); + default: + break; + } + + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND); + return 1; +} + +void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level) +{ + u64 shared_bit = (pgd_level == 5) ? TDX_SHARED_BIT_PWL_5 : + TDX_SHARED_BIT_PWL_4; + + if (KVM_BUG_ON(shared_bit != kvm_gfn_direct_bits(vcpu->kvm), vcpu->kvm)) + return; + + td_vmcs_write64(to_tdx(vcpu), SHARED_EPT_POINTER, root_hpa); +} + +static void tdx_unpin(struct kvm *kvm, struct page *page) +{ + put_page(page); +} + +static int tdx_mem_page_aug(struct kvm *kvm, gfn_t gfn, + enum pg_level level, struct page *page) +{ + int tdx_level = pg_level_to_tdx_sept_level(level); + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + gpa_t gpa = gfn_to_gpa(gfn); + u64 entry, level_state; + u64 err; + + err = tdh_mem_page_aug(&kvm_tdx->td, gpa, tdx_level, page, &entry, &level_state); + if (unlikely(tdx_operand_busy(err))) { + tdx_unpin(kvm, page); + return -EBUSY; + } + + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error_2(TDH_MEM_PAGE_AUG, err, entry, level_state); + tdx_unpin(kvm, page); + return -EIO; + } + + return 0; +} + +/* + * KVM_TDX_INIT_MEM_REGION calls kvm_gmem_populate() to map guest pages; the + * callback tdx_gmem_post_populate() then maps pages into private memory. + * through the a seamcall TDH.MEM.PAGE.ADD(). The SEAMCALL also requires the + * private EPT structures for the page to have been built before, which is + * done via kvm_tdp_map_page(). nr_premapped counts the number of pages that + * were added to the EPT structures but not added with TDH.MEM.PAGE.ADD(). + * The counter has to be zero on KVM_TDX_FINALIZE_VM, to ensure that there + * are no half-initialized shared EPT pages. + */ +static int tdx_mem_page_record_premap_cnt(struct kvm *kvm, gfn_t gfn, + enum pg_level level, kvm_pfn_t pfn) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + + if (KVM_BUG_ON(kvm->arch.pre_fault_allowed, kvm)) + return -EINVAL; + + /* nr_premapped will be decreased when tdh_mem_page_add() is called. */ + atomic64_inc(&kvm_tdx->nr_premapped); + return 0; +} + +int tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn, + enum pg_level level, kvm_pfn_t pfn) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + struct page *page = pfn_to_page(pfn); + + /* TODO: handle large pages. */ + if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm)) + return -EINVAL; + + /* + * Because guest_memfd doesn't support page migration with + * a_ops->migrate_folio (yet), no callback is triggered for KVM on page + * migration. Until guest_memfd supports page migration, prevent page + * migration. + * TODO: Once guest_memfd introduces callback on page migration, + * implement it and remove get_page/put_page(). + */ + get_page(page); + + /* + * Read 'pre_fault_allowed' before 'kvm_tdx->state'; see matching + * barrier in tdx_td_finalize(). + */ + smp_rmb(); + if (likely(kvm_tdx->state == TD_STATE_RUNNABLE)) + return tdx_mem_page_aug(kvm, gfn, level, page); + + return tdx_mem_page_record_premap_cnt(kvm, gfn, level, pfn); +} + +static int tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn, + enum pg_level level, struct page *page) +{ + int tdx_level = pg_level_to_tdx_sept_level(level); + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + gpa_t gpa = gfn_to_gpa(gfn); + u64 err, entry, level_state; + + /* TODO: handle large pages. */ + if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm)) + return -EINVAL; + + if (KVM_BUG_ON(!is_hkid_assigned(kvm_tdx), kvm)) + return -EINVAL; + + /* + * When zapping private page, write lock is held. So no race condition + * with other vcpu sept operation. + * Race with TDH.VP.ENTER due to (0-step mitigation) and Guest TDCALLs. + */ + err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry, + &level_state); + + if (unlikely(tdx_operand_busy(err))) { + /* + * The second retry is expected to succeed after kicking off all + * other vCPUs and prevent them from invoking TDH.VP.ENTER. + */ + tdx_no_vcpus_enter_start(kvm); + err = tdh_mem_page_remove(&kvm_tdx->td, gpa, tdx_level, &entry, + &level_state); + tdx_no_vcpus_enter_stop(kvm); + } + + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error_2(TDH_MEM_PAGE_REMOVE, err, entry, level_state); + return -EIO; + } + + err = tdh_phymem_page_wbinvd_hkid((u16)kvm_tdx->hkid, page); + + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err); + return -EIO; + } + tdx_clear_page(page); + tdx_unpin(kvm, page); + return 0; +} + +int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn, + enum pg_level level, void *private_spt) +{ + int tdx_level = pg_level_to_tdx_sept_level(level); + gpa_t gpa = gfn_to_gpa(gfn); + struct page *page = virt_to_page(private_spt); + u64 err, entry, level_state; + + err = tdh_mem_sept_add(&to_kvm_tdx(kvm)->td, gpa, tdx_level, page, &entry, + &level_state); + if (unlikely(tdx_operand_busy(err))) + return -EBUSY; + + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error_2(TDH_MEM_SEPT_ADD, err, entry, level_state); + return -EIO; + } + + return 0; +} + +/* + * Check if the error returned from a SEPT zap SEAMCALL is due to that a page is + * mapped by KVM_TDX_INIT_MEM_REGION without tdh_mem_page_add() being called + * successfully. + * + * Since tdh_mem_sept_add() must have been invoked successfully before a + * non-leaf entry present in the mirrored page table, the SEPT ZAP related + * SEAMCALLs should not encounter err TDX_EPT_WALK_FAILED. They should instead + * find TDX_EPT_ENTRY_STATE_INCORRECT due to an empty leaf entry found in the + * SEPT. + * + * Further check if the returned entry from SEPT walking is with RWX permissions + * to filter out anything unexpected. + * + * Note: @level is pg_level, not the tdx_level. The tdx_level extracted from + * level_state returned from a SEAMCALL error is the same as that passed into + * the SEAMCALL. + */ +static int tdx_is_sept_zap_err_due_to_premap(struct kvm_tdx *kvm_tdx, u64 err, + u64 entry, int level) +{ + if (!err || kvm_tdx->state == TD_STATE_RUNNABLE) + return false; + + if (err != (TDX_EPT_ENTRY_STATE_INCORRECT | TDX_OPERAND_ID_RCX)) + return false; + + if ((is_last_spte(entry, level) && (entry & VMX_EPT_RWX_MASK))) + return false; + + return true; +} + +static int tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn, + enum pg_level level, struct page *page) +{ + int tdx_level = pg_level_to_tdx_sept_level(level); + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + gpa_t gpa = gfn_to_gpa(gfn) & KVM_HPAGE_MASK(level); + u64 err, entry, level_state; + + /* For now large page isn't supported yet. */ + WARN_ON_ONCE(level != PG_LEVEL_4K); + + err = tdh_mem_range_block(&kvm_tdx->td, gpa, tdx_level, &entry, &level_state); + + if (unlikely(tdx_operand_busy(err))) { + /* After no vCPUs enter, the second retry is expected to succeed */ + tdx_no_vcpus_enter_start(kvm); + err = tdh_mem_range_block(&kvm_tdx->td, gpa, tdx_level, &entry, &level_state); + tdx_no_vcpus_enter_stop(kvm); + } + if (tdx_is_sept_zap_err_due_to_premap(kvm_tdx, err, entry, level) && + !KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) { + atomic64_dec(&kvm_tdx->nr_premapped); + tdx_unpin(kvm, page); + return 0; + } + + if (KVM_BUG_ON(err, kvm)) { + pr_tdx_error_2(TDH_MEM_RANGE_BLOCK, err, entry, level_state); + return -EIO; + } + return 1; +} + +/* + * Ensure shared and private EPTs to be flushed on all vCPUs. + * tdh_mem_track() is the only caller that increases TD epoch. An increase in + * the TD epoch (e.g., to value "N + 1") is successful only if no vCPUs are + * running in guest mode with the value "N - 1". + * + * A successful execution of tdh_mem_track() ensures that vCPUs can only run in + * guest mode with TD epoch value "N" if no TD exit occurs after the TD epoch + * being increased to "N + 1". + * + * Kicking off all vCPUs after that further results in no vCPUs can run in guest + * mode with TD epoch value "N", which unblocks the next tdh_mem_track() (e.g. + * to increase TD epoch to "N + 2"). + * + * TDX module will flush EPT on the next TD enter and make vCPUs to run in + * guest mode with TD epoch value "N + 1". + * + * kvm_make_all_cpus_request() guarantees all vCPUs are out of guest mode by + * waiting empty IPI handler ack_kick(). + * + * No action is required to the vCPUs being kicked off since the kicking off + * occurs certainly after TD epoch increment and before the next + * tdh_mem_track(). + */ +static void tdx_track(struct kvm *kvm) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + u64 err; + + /* If TD isn't finalized, it's before any vcpu running. */ + if (unlikely(kvm_tdx->state != TD_STATE_RUNNABLE)) + return; + + lockdep_assert_held_write(&kvm->mmu_lock); + + err = tdh_mem_track(&kvm_tdx->td); + if (unlikely(tdx_operand_busy(err))) { + /* After no vCPUs enter, the second retry is expected to succeed */ + tdx_no_vcpus_enter_start(kvm); + err = tdh_mem_track(&kvm_tdx->td); + tdx_no_vcpus_enter_stop(kvm); + } + + if (KVM_BUG_ON(err, kvm)) + pr_tdx_error(TDH_MEM_TRACK, err); + + kvm_make_all_cpus_request(kvm, KVM_REQ_OUTSIDE_GUEST_MODE); +} + +int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn, + enum pg_level level, void *private_spt) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + + /* + * free_external_spt() is only called after hkid is freed when TD is + * tearing down. + * KVM doesn't (yet) zap page table pages in mirror page table while + * TD is active, though guest pages mapped in mirror page table could be + * zapped during TD is active, e.g. for shared <-> private conversion + * and slot move/deletion. + */ + if (KVM_BUG_ON(is_hkid_assigned(kvm_tdx), kvm)) + return -EINVAL; + + /* + * The HKID assigned to this TD was already freed and cache was + * already flushed. We don't have to flush again. + */ + return tdx_reclaim_page(virt_to_page(private_spt)); +} + +int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn, + enum pg_level level, kvm_pfn_t pfn) +{ + struct page *page = pfn_to_page(pfn); + int ret; + + /* + * HKID is released after all private pages have been removed, and set + * before any might be populated. Warn if zapping is attempted when + * there can't be anything populated in the private EPT. + */ + if (KVM_BUG_ON(!is_hkid_assigned(to_kvm_tdx(kvm)), kvm)) + return -EINVAL; + + ret = tdx_sept_zap_private_spte(kvm, gfn, level, page); + if (ret <= 0) + return ret; + + /* + * TDX requires TLB tracking before dropping private page. Do + * it here, although it is also done later. + */ + tdx_track(kvm); + + return tdx_sept_drop_private_spte(kvm, gfn, level, page); +} + +void tdx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode, + int trig_mode, int vector) +{ + struct kvm_vcpu *vcpu = apic->vcpu; + struct vcpu_tdx *tdx = to_tdx(vcpu); + + /* TDX supports only posted interrupt. No lapic emulation. */ + __vmx_deliver_posted_interrupt(vcpu, &tdx->vt.pi_desc, vector); + + trace_kvm_apicv_accept_irq(vcpu->vcpu_id, delivery_mode, trig_mode, vector); +} + +static inline bool tdx_is_sept_violation_unexpected_pending(struct kvm_vcpu *vcpu) +{ + u64 eeq_type = to_tdx(vcpu)->ext_exit_qualification & TDX_EXT_EXIT_QUAL_TYPE_MASK; + u64 eq = vmx_get_exit_qual(vcpu); + + if (eeq_type != TDX_EXT_EXIT_QUAL_TYPE_PENDING_EPT_VIOLATION) + return false; + + return !(eq & EPT_VIOLATION_PROT_MASK) && !(eq & EPT_VIOLATION_EXEC_FOR_RING3_LIN); +} + +static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu) +{ + unsigned long exit_qual; + gpa_t gpa = to_tdx(vcpu)->exit_gpa; + bool local_retry = false; + int ret; + + if (vt_is_tdx_private_gpa(vcpu->kvm, gpa)) { + if (tdx_is_sept_violation_unexpected_pending(vcpu)) { + pr_warn("Guest access before accepting 0x%llx on vCPU %d\n", + gpa, vcpu->vcpu_id); + kvm_vm_dead(vcpu->kvm); + return -EIO; + } + /* + * Always treat SEPT violations as write faults. Ignore the + * EXIT_QUALIFICATION reported by TDX-SEAM for SEPT violations. + * TD private pages are always RWX in the SEPT tables, + * i.e. they're always mapped writable. Just as importantly, + * treating SEPT violations as write faults is necessary to + * avoid COW allocations, which will cause TDAUGPAGE failures + * due to aliasing a single HPA to multiple GPAs. + */ + exit_qual = EPT_VIOLATION_ACC_WRITE; + + /* Only private GPA triggers zero-step mitigation */ + local_retry = true; + } else { + exit_qual = vmx_get_exit_qual(vcpu); + /* + * EPT violation due to instruction fetch should never be + * triggered from shared memory in TDX guest. If such EPT + * violation occurs, treat it as broken hardware. + */ + if (KVM_BUG_ON(exit_qual & EPT_VIOLATION_ACC_INSTR, vcpu->kvm)) + return -EIO; + } + + trace_kvm_page_fault(vcpu, gpa, exit_qual); + + /* + * To minimize TDH.VP.ENTER invocations, retry locally for private GPA + * mapping in TDX. + * + * KVM may return RET_PF_RETRY for private GPA due to + * - contentions when atomically updating SPTEs of the mirror page table + * - in-progress GFN invalidation or memslot removal. + * - TDX_OPERAND_BUSY error from TDH.MEM.PAGE.AUG or TDH.MEM.SEPT.ADD, + * caused by contentions with TDH.VP.ENTER (with zero-step mitigation) + * or certain TDCALLs. + * + * If TDH.VP.ENTER is invoked more times than the threshold set by the + * TDX module before KVM resolves the private GPA mapping, the TDX + * module will activate zero-step mitigation during TDH.VP.ENTER. This + * process acquires an SEPT tree lock in the TDX module, leading to + * further contentions with TDH.MEM.PAGE.AUG or TDH.MEM.SEPT.ADD + * operations on other vCPUs. + * + * Breaking out of local retries for kvm_vcpu_has_events() is for + * interrupt injection. kvm_vcpu_has_events() should not see pending + * events for TDX. Since KVM can't determine if IRQs (or NMIs) are + * blocked by TDs, false positives are inevitable i.e., KVM may re-enter + * the guest even if the IRQ/NMI can't be delivered. + * + * Note: even without breaking out of local retries, zero-step + * mitigation may still occur due to + * - invoking of TDH.VP.ENTER after KVM_EXIT_MEMORY_FAULT, + * - a single RIP causing EPT violations for more GFNs than the + * threshold count. + * This is safe, as triggering zero-step mitigation only introduces + * contentions to page installation SEAMCALLs on other vCPUs, which will + * handle retries locally in their EPT violation handlers. + */ + while (1) { + ret = __vmx_handle_ept_violation(vcpu, gpa, exit_qual); + + if (ret != RET_PF_RETRY || !local_retry) + break; + + if (kvm_vcpu_has_events(vcpu) || signal_pending(current)) + break; + + if (kvm_check_request(KVM_REQ_VM_DEAD, vcpu)) { + ret = -EIO; + break; + } + + cond_resched(); + } + return ret; +} + +int tdx_complete_emulated_msr(struct kvm_vcpu *vcpu, int err) +{ + if (err) { + tdvmcall_set_return_code(vcpu, TDVMCALL_STATUS_INVALID_OPERAND); + return 1; + } + + if (vmx_get_exit_reason(vcpu).basic == EXIT_REASON_MSR_READ) + tdvmcall_set_return_val(vcpu, kvm_read_edx_eax(vcpu)); + + return 1; +} + + +int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + u64 vp_enter_ret = tdx->vp_enter_ret; + union vmx_exit_reason exit_reason = vmx_get_exit_reason(vcpu); + + if (fastpath != EXIT_FASTPATH_NONE) + return 1; + + if (unlikely(vp_enter_ret == EXIT_REASON_EPT_MISCONFIG)) { + KVM_BUG_ON(1, vcpu->kvm); + return -EIO; + } + + /* + * Handle TDX SW errors, including TDX_SEAMCALL_UD, TDX_SEAMCALL_GP and + * TDX_SEAMCALL_VMFAILINVALID. + */ + if (unlikely((vp_enter_ret & TDX_SW_ERROR) == TDX_SW_ERROR)) { + KVM_BUG_ON(!kvm_rebooting, vcpu->kvm); + goto unhandled_exit; + } + + if (unlikely(tdx_failed_vmentry(vcpu))) { + /* + * If the guest state is protected, that means off-TD debug is + * not enabled, TDX_NON_RECOVERABLE must be set. + */ + WARN_ON_ONCE(vcpu->arch.guest_state_protected && + !(vp_enter_ret & TDX_NON_RECOVERABLE)); + vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY; + vcpu->run->fail_entry.hardware_entry_failure_reason = exit_reason.full; + vcpu->run->fail_entry.cpu = vcpu->arch.last_vmentry_cpu; + return 0; + } + + if (unlikely(vp_enter_ret & (TDX_ERROR | TDX_NON_RECOVERABLE)) && + exit_reason.basic != EXIT_REASON_TRIPLE_FAULT) { + kvm_pr_unimpl("TD vp_enter_ret 0x%llx\n", vp_enter_ret); + goto unhandled_exit; + } + + WARN_ON_ONCE(exit_reason.basic != EXIT_REASON_TRIPLE_FAULT && + (vp_enter_ret & TDX_SEAMCALL_STATUS_MASK) != TDX_SUCCESS); + + switch (exit_reason.basic) { + case EXIT_REASON_TRIPLE_FAULT: + vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN; + vcpu->mmio_needed = 0; + return 0; + case EXIT_REASON_EXCEPTION_NMI: + return tdx_handle_exception_nmi(vcpu); + case EXIT_REASON_EXTERNAL_INTERRUPT: + ++vcpu->stat.irq_exits; + return 1; + case EXIT_REASON_CPUID: + return tdx_emulate_cpuid(vcpu); + case EXIT_REASON_HLT: + return kvm_emulate_halt_noskip(vcpu); + case EXIT_REASON_TDCALL: + return handle_tdvmcall(vcpu); + case EXIT_REASON_VMCALL: + return tdx_emulate_vmcall(vcpu); + case EXIT_REASON_IO_INSTRUCTION: + return tdx_emulate_io(vcpu); + case EXIT_REASON_MSR_READ: + kvm_rcx_write(vcpu, tdx->vp_enter_args.r12); + return kvm_emulate_rdmsr(vcpu); + case EXIT_REASON_MSR_WRITE: + kvm_rcx_write(vcpu, tdx->vp_enter_args.r12); + kvm_rax_write(vcpu, tdx->vp_enter_args.r13 & -1u); + kvm_rdx_write(vcpu, tdx->vp_enter_args.r13 >> 32); + return kvm_emulate_wrmsr(vcpu); + case EXIT_REASON_EPT_MISCONFIG: + return tdx_emulate_mmio(vcpu); + case EXIT_REASON_EPT_VIOLATION: + return tdx_handle_ept_violation(vcpu); + case EXIT_REASON_OTHER_SMI: + /* + * Unlike VMX, SMI in SEAM non-root mode (i.e. when + * TD guest vCPU is running) will cause VM exit to TDX module, + * then SEAMRET to KVM. Once it exits to KVM, SMI is delivered + * and handled by kernel handler right away. + * + * The Other SMI exit can also be caused by the SEAM non-root + * machine check delivered via Machine Check System Management + * Interrupt (MSMI), but it has already been handled by the + * kernel machine check handler, i.e., the memory page has been + * marked as poisoned and it won't be freed to the free list + * when the TDX guest is terminated (the TDX module marks the + * guest as dead and prevent it from further running when + * machine check happens in SEAM non-root). + * + * - A MSMI will not reach here, it's handled as non_recoverable + * case above. + * - If it's not an MSMI, no need to do anything here. + */ + return 1; + default: + break; + } + +unhandled_exit: + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON; + vcpu->run->internal.ndata = 2; + vcpu->run->internal.data[0] = vp_enter_ret; + vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu; + return 0; +} + +void tdx_get_exit_info(struct kvm_vcpu *vcpu, u32 *reason, + u64 *info1, u64 *info2, u32 *intr_info, u32 *error_code) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + + *reason = tdx->vt.exit_reason.full; + if (*reason != -1u) { + *info1 = vmx_get_exit_qual(vcpu); + *info2 = tdx->ext_exit_qualification; + *intr_info = vmx_get_intr_info(vcpu); + } else { + *info1 = 0; + *info2 = 0; + *intr_info = 0; + } + + *error_code = 0; +} + +bool tdx_has_emulated_msr(u32 index) +{ + switch (index) { + case MSR_IA32_UCODE_REV: + case MSR_IA32_ARCH_CAPABILITIES: + case MSR_IA32_POWER_CTL: + case MSR_IA32_CR_PAT: + case MSR_MTRRcap: + case MTRRphysBase_MSR(0) ... MSR_MTRRfix4K_F8000: + case MSR_MTRRdefType: + case MSR_IA32_TSC_DEADLINE: + case MSR_IA32_MISC_ENABLE: + case MSR_PLATFORM_INFO: + case MSR_MISC_FEATURES_ENABLES: + case MSR_IA32_APICBASE: + case MSR_EFER: + case MSR_IA32_FEAT_CTL: + case MSR_IA32_MCG_CAP: + case MSR_IA32_MCG_STATUS: + case MSR_IA32_MCG_CTL: + case MSR_IA32_MCG_EXT_CTL: + case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1: + case MSR_IA32_MC0_CTL2 ... MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) - 1: + /* MSR_IA32_MCx_{CTL, STATUS, ADDR, MISC, CTL2} */ + case MSR_KVM_POLL_CONTROL: + return true; + case APIC_BASE_MSR ... APIC_BASE_MSR + 0xff: + /* + * x2APIC registers that are virtualized by the CPU can't be + * emulated, KVM doesn't have access to the virtual APIC page. + */ + switch (index) { + case X2APIC_MSR(APIC_TASKPRI): + case X2APIC_MSR(APIC_PROCPRI): + case X2APIC_MSR(APIC_EOI): + case X2APIC_MSR(APIC_ISR) ... X2APIC_MSR(APIC_ISR + APIC_ISR_NR): + case X2APIC_MSR(APIC_TMR) ... X2APIC_MSR(APIC_TMR + APIC_ISR_NR): + case X2APIC_MSR(APIC_IRR) ... X2APIC_MSR(APIC_IRR + APIC_ISR_NR): + return false; + default: + return true; + } + default: + return false; + } +} + +static bool tdx_is_read_only_msr(u32 index) +{ + return index == MSR_IA32_APICBASE || index == MSR_EFER || + index == MSR_IA32_FEAT_CTL; +} + +int tdx_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) +{ + switch (msr->index) { + case MSR_IA32_FEAT_CTL: + /* + * MCE and MCA are advertised via cpuid. Guest kernel could + * check if LMCE is enabled or not. + */ + msr->data = FEAT_CTL_LOCKED; + if (vcpu->arch.mcg_cap & MCG_LMCE_P) + msr->data |= FEAT_CTL_LMCE_ENABLED; + return 0; + case MSR_IA32_MCG_EXT_CTL: + if (!msr->host_initiated && !(vcpu->arch.mcg_cap & MCG_LMCE_P)) + return 1; + msr->data = vcpu->arch.mcg_ext_ctl; + return 0; + default: + if (!tdx_has_emulated_msr(msr->index)) + return 1; + + return kvm_get_msr_common(vcpu, msr); + } +} + +int tdx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) +{ + switch (msr->index) { + case MSR_IA32_MCG_EXT_CTL: + if ((!msr->host_initiated && !(vcpu->arch.mcg_cap & MCG_LMCE_P)) || + (msr->data & ~MCG_EXT_CTL_LMCE_EN)) + return 1; + vcpu->arch.mcg_ext_ctl = msr->data; + return 0; + default: + if (tdx_is_read_only_msr(msr->index)) + return 1; + + if (!tdx_has_emulated_msr(msr->index)) + return 1; + + return kvm_set_msr_common(vcpu, msr); + } +} + +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; +} + +/* + * 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; + + if (tdx_unsupported_cpuid(entry)) + return -EINVAL; + + 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, rcx; + + *seamcall_err = 0; + ret = tdx_guest_keyid_alloc(); + if (ret < 0) + return ret; + kvm_tdx->hkid = ret; + kvm_tdx->misc_cg = get_current_misc_cg(); + ret = misc_cg_try_charge(MISC_CG_RES_TDX, kvm_tdx->misc_cg, 1); + if (ret) + goto free_hkid; + + ret = -ENOMEM; + + atomic_inc(&nr_configured_hkid); + + tdr_page = alloc_page(GFP_KERNEL); + if (!tdr_page) + goto free_hkid; + + kvm_tdx->td.tdcs_nr_pages = tdx_sysinfo->td_ctrl.tdcs_base_size / PAGE_SIZE; + /* TDVPS = TDVPR(4K page) + TDCX(multiple 4K pages), -1 for TDVPR. */ + kvm_tdx->td.tdcx_nr_pages = tdx_sysinfo->td_ctrl.tdvps_base_size / PAGE_SIZE - 1; + tdcs_pages = kcalloc(kvm_tdx->td.tdcs_nr_pages, sizeof(*kvm_tdx->td.tdcs_pages), + GFP_KERNEL | __GFP_ZERO); + if (!tdcs_pages) + goto free_tdr; + + for (i = 0; i < kvm_tdx->td.tdcs_nr_pages; i++) { + tdcs_pages[i] = alloc_page(GFP_KERNEL); + if (!tdcs_pages[i]) + goto free_tdcs; + } + + if (!zalloc_cpumask_var(&packages, GFP_KERNEL)) + goto free_tdcs; + + cpus_read_lock(); + + /* + * Need at least one CPU of the package to be online in order to + * program all packages for host key id. Check it. + */ + for_each_present_cpu(i) + cpumask_set_cpu(topology_physical_package_id(i), packages); + for_each_online_cpu(i) + cpumask_clear_cpu(topology_physical_package_id(i), packages); + if (!cpumask_empty(packages)) { + ret = -EIO; + /* + * Because it's hard for human operator to figure out the + * reason, warn it. + */ +#define MSG_ALLPKG "All packages need to have online CPU to create TD. Online CPU and retry.\n" + pr_warn_ratelimited(MSG_ALLPKG); + goto free_packages; + } + + /* + * TDH.MNG.CREATE tries to grab the global TDX module and fails + * with TDX_OPERAND_BUSY when it fails to grab. Take the global + * lock to prevent it from failure. + */ + mutex_lock(&tdx_lock); + kvm_tdx->td.tdr_page = tdr_page; + err = tdh_mng_create(&kvm_tdx->td, kvm_tdx->hkid); + mutex_unlock(&tdx_lock); + + if (err == TDX_RND_NO_ENTROPY) { + ret = -EAGAIN; + goto free_packages; + } + + if (WARN_ON_ONCE(err)) { + pr_tdx_error(TDH_MNG_CREATE, err); + ret = -EIO; + goto free_packages; + } + + for_each_online_cpu(i) { + int pkg = topology_physical_package_id(i); + + if (cpumask_test_and_set_cpu(pkg, packages)) + continue; + + /* + * Program the memory controller in the package with an + * encryption key associated to a TDX private host key id + * assigned to this TDR. Concurrent operations on same memory + * controller results in TDX_OPERAND_BUSY. No locking needed + * beyond the cpus_read_lock() above as it serializes against + * hotplug and the first online CPU of the package is always + * used. We never have two CPUs in the same socket trying to + * program the key. + */ + ret = smp_call_on_cpu(i, tdx_do_tdh_mng_key_config, + kvm_tdx, true); + if (ret) + break; + } + cpus_read_unlock(); + free_cpumask_var(packages); + if (ret) { + i = 0; + goto teardown; + } + + kvm_tdx->td.tdcs_pages = tdcs_pages; + for (i = 0; i < kvm_tdx->td.tdcs_nr_pages; i++) { + err = tdh_mng_addcx(&kvm_tdx->td, tdcs_pages[i]); + if (err == TDX_RND_NO_ENTROPY) { + /* Here it's hard to allow userspace to retry. */ + ret = -EAGAIN; + goto teardown; + } + if (WARN_ON_ONCE(err)) { + pr_tdx_error(TDH_MNG_ADDCX, err); + ret = -EIO; + goto teardown; + } + } + + 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; + + /* + * The sequence for freeing resources from a partially initialized TD + * varies based on where in the initialization flow failure occurred. + * Simply use the full teardown and destroy, which naturally play nice + * with partial initialization. + */ +teardown: + /* Only free pages not yet added, so start at 'i' */ + for (; i < kvm_tdx->td.tdcs_nr_pages; i++) { + if (tdcs_pages[i]) { + __free_page(tdcs_pages[i]); + tdcs_pages[i] = NULL; + } + } + if (!kvm_tdx->td.tdcs_pages) + kfree(tdcs_pages); + + tdx_mmu_release_hkid(kvm); + tdx_reclaim_td_control_pages(kvm); + + return ret; + +free_packages: + cpus_read_unlock(); + free_cpumask_var(packages); + +free_tdcs: + for (i = 0; i < kvm_tdx->td.tdcs_nr_pages; i++) { + if (tdcs_pages[i]) + __free_page(tdcs_pages[i]); + } + kfree(tdcs_pages); + kvm_tdx->td.tdcs_pages = NULL; + +free_tdr: + if (tdr_page) + __free_page(tdr_page); + kvm_tdx->td.tdr_page = 0; + +free_hkid: + tdx_hkid_free(kvm_tdx); + + return ret; +} + +static u64 tdx_td_metadata_field_read(struct kvm_tdx *tdx, u64 field_id, + u64 *data) +{ + u64 err; + + err = tdh_mng_rd(&tdx->td, field_id, data); + + return err; +} + +#define TDX_MD_UNREADABLE_LEAF_MASK GENMASK(30, 7) +#define TDX_MD_UNREADABLE_SUBLEAF_MASK GENMASK(31, 7) + +static int tdx_read_cpuid(struct kvm_vcpu *vcpu, u32 leaf, u32 sub_leaf, + bool sub_leaf_set, int *entry_index, + struct kvm_cpuid_entry2 *out) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + u64 field_id = TD_MD_FIELD_ID_CPUID_VALUES; + u64 ebx_eax, edx_ecx; + u64 err = 0; + + if (sub_leaf > 0b1111111) + return -EINVAL; + + if (*entry_index >= KVM_MAX_CPUID_ENTRIES) + return -EINVAL; + + if (leaf & TDX_MD_UNREADABLE_LEAF_MASK || + sub_leaf & TDX_MD_UNREADABLE_SUBLEAF_MASK) + return -EINVAL; + + /* + * bit 23:17, REVSERVED: reserved, must be 0; + * bit 16, LEAF_31: leaf number bit 31; + * bit 15:9, LEAF_6_0: leaf number bits 6:0, leaf bits 30:7 are + * implicitly 0; + * bit 8, SUBLEAF_NA: sub-leaf not applicable flag; + * bit 7:1, SUBLEAF_6_0: sub-leaf number bits 6:0. If SUBLEAF_NA is 1, + * the SUBLEAF_6_0 is all-1. + * sub-leaf bits 31:7 are implicitly 0; + * bit 0, ELEMENT_I: Element index within field; + */ + field_id |= ((leaf & 0x80000000) ? 1 : 0) << 16; + field_id |= (leaf & 0x7f) << 9; + if (sub_leaf_set) + field_id |= (sub_leaf & 0x7f) << 1; + else + field_id |= 0x1fe; + + err = tdx_td_metadata_field_read(kvm_tdx, field_id, &ebx_eax); + if (err) //TODO check for specific errors + goto err_out; + + out->eax = (u32) ebx_eax; + out->ebx = (u32) (ebx_eax >> 32); + + field_id++; + err = tdx_td_metadata_field_read(kvm_tdx, field_id, &edx_ecx); + /* + * It's weird that reading edx_ecx fails while reading ebx_eax + * succeeded. + */ + if (WARN_ON_ONCE(err)) + goto err_out; + + out->ecx = (u32) edx_ecx; + out->edx = (u32) (edx_ecx >> 32); + + out->function = leaf; + out->index = sub_leaf; + out->flags |= sub_leaf_set ? KVM_CPUID_FLAG_SIGNIFCANT_INDEX : 0; + + /* + * Work around missing support on old TDX modules, fetch + * guest maxpa from gfn_direct_bits. + */ + if (leaf == 0x80000008) { + gpa_t gpa_bits = gfn_to_gpa(kvm_gfn_direct_bits(vcpu->kvm)); + unsigned int g_maxpa = __ffs(gpa_bits) + 1; + + out->eax = tdx_set_guest_phys_addr_bits(out->eax, g_maxpa); + } + + (*entry_index)++; + + return 0; + +err_out: + out->eax = 0; + out->ebx = 0; + out->ecx = 0; + out->edx = 0; + + return -EIO; +} + +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->tsc_multiplier = td_tdcs_exec_read64(kvm_tdx, TD_TDCS_EXEC_TSC_MULTIPLIER); + kvm_tdx->attributes = td_params->attributes; + kvm_tdx->xfam = td_params->xfam; + + if (td_params->config_flags & TDX_CONFIG_FLAGS_MAX_GPAW) + kvm->arch.gfn_direct_bits = TDX_SHARED_BIT_PWL_5; + else + kvm->arch.gfn_direct_bits = TDX_SHARED_BIT_PWL_4; + + kvm_tdx->state = TD_STATE_INITIALIZED; +out: + /* kfree() accepts NULL. */ + kfree(init_vm); + kfree(td_params); + + return ret; +} + +void tdx_flush_tlb_current(struct kvm_vcpu *vcpu) +{ + /* + * flush_tlb_current() is invoked when the first time for the vcpu to + * run or when root of shared EPT is invalidated. + * KVM only needs to flush shared EPT because the TDX module handles TLB + * invalidation for private EPT in tdh_vp_enter(); + * + * A single context invalidation for shared EPT can be performed here. + * However, this single context invalidation requires the private EPTP + * rather than the shared EPTP to flush shared EPT, as shared EPT uses + * private EPTP as its ASID for TLB invalidation. + * + * To avoid reading back private EPTP, perform a global invalidation for + * shared EPT instead to keep this function simple. + */ + ept_sync_global(); +} + +void tdx_flush_tlb_all(struct kvm_vcpu *vcpu) +{ + /* + * TDX has called tdx_track() in tdx_sept_remove_private_spte() to + * ensure that private EPT will be flushed on the next TD enter. No need + * to call tdx_track() here again even when this callback is a result of + * zapping private EPT. + * + * Due to the lack of the context to determine which EPT has been + * affected by zapping, invoke invept() directly here for both shared + * EPT and private EPT for simplicity, though it's not necessary for + * private EPT. + */ + ept_sync_global(); +} + +static int tdx_td_finalize(struct kvm *kvm, struct kvm_tdx_cmd *cmd) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + + guard(mutex)(&kvm->slots_lock); + + if (!is_hkid_assigned(kvm_tdx) || kvm_tdx->state == TD_STATE_RUNNABLE) + return -EINVAL; + /* + * Pages are pending for KVM_TDX_INIT_MEM_REGION to issue + * TDH.MEM.PAGE.ADD(). + */ + if (atomic64_read(&kvm_tdx->nr_premapped)) + return -EINVAL; + + cmd->hw_error = tdh_mr_finalize(&kvm_tdx->td); + if (tdx_operand_busy(cmd->hw_error)) + return -EBUSY; + if (KVM_BUG_ON(cmd->hw_error, kvm)) { + pr_tdx_error(TDH_MR_FINALIZE, cmd->hw_error); + return -EIO; + } + + kvm_tdx->state = TD_STATE_RUNNABLE; + /* TD_STATE_RUNNABLE must be set before 'pre_fault_allowed' */ + smp_wmb(); + kvm->arch.pre_fault_allowed = true; + return 0; +} + +int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) +{ + struct kvm_tdx_cmd tdx_cmd; + int r; + + if (copy_from_user(&tdx_cmd, argp, sizeof(struct kvm_tdx_cmd))) + return -EFAULT; + + /* + * Userspace should never set hw_error. It is used to fill + * hardware-defined error by the kernel. + */ + if (tdx_cmd.hw_error) + return -EINVAL; + + mutex_lock(&kvm->lock); + + switch (tdx_cmd.id) { + case KVM_TDX_CAPABILITIES: + r = tdx_get_capabilities(&tdx_cmd); + break; + case KVM_TDX_INIT_VM: + r = tdx_td_init(kvm, &tdx_cmd); + break; + case KVM_TDX_FINALIZE_VM: + r = tdx_td_finalize(kvm, &tdx_cmd); + break; + default: + r = -EINVAL; + goto out; + } + + if (copy_to_user(argp, &tdx_cmd, sizeof(struct kvm_tdx_cmd))) + r = -EFAULT; + +out: + mutex_unlock(&kvm->lock); + return r; +} + +/* VMM can pass one 64bit auxiliary data to vcpu via RCX for guest BIOS. */ +static int tdx_td_vcpu_init(struct kvm_vcpu *vcpu, u64 vcpu_rcx) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + struct vcpu_tdx *tdx = to_tdx(vcpu); + struct page *page; + int ret, i; + u64 err; + + page = alloc_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + tdx->vp.tdvpr_page = page; + + tdx->vp.tdcx_pages = kcalloc(kvm_tdx->td.tdcx_nr_pages, sizeof(*tdx->vp.tdcx_pages), + GFP_KERNEL); + if (!tdx->vp.tdcx_pages) { + ret = -ENOMEM; + goto free_tdvpr; + } + + for (i = 0; i < kvm_tdx->td.tdcx_nr_pages; i++) { + page = alloc_page(GFP_KERNEL); + if (!page) { + ret = -ENOMEM; + goto free_tdcx; + } + tdx->vp.tdcx_pages[i] = page; + } + + err = tdh_vp_create(&kvm_tdx->td, &tdx->vp); + if (KVM_BUG_ON(err, vcpu->kvm)) { + ret = -EIO; + pr_tdx_error(TDH_VP_CREATE, err); + goto free_tdcx; + } + + for (i = 0; i < kvm_tdx->td.tdcx_nr_pages; i++) { + err = tdh_vp_addcx(&tdx->vp, tdx->vp.tdcx_pages[i]); + if (KVM_BUG_ON(err, vcpu->kvm)) { + pr_tdx_error(TDH_VP_ADDCX, err); + /* + * Pages already added are reclaimed by the vcpu_free + * method, but the rest are freed here. + */ + for (; i < kvm_tdx->td.tdcx_nr_pages; i++) { + __free_page(tdx->vp.tdcx_pages[i]); + tdx->vp.tdcx_pages[i] = NULL; + } + return -EIO; + } + } + + err = tdh_vp_init(&tdx->vp, vcpu_rcx, vcpu->vcpu_id); + if (KVM_BUG_ON(err, vcpu->kvm)) { + pr_tdx_error(TDH_VP_INIT, err); + return -EIO; + } + + vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; + + return 0; + +free_tdcx: + for (i = 0; i < kvm_tdx->td.tdcx_nr_pages; i++) { + if (tdx->vp.tdcx_pages[i]) + __free_page(tdx->vp.tdcx_pages[i]); + tdx->vp.tdcx_pages[i] = NULL; + } + kfree(tdx->vp.tdcx_pages); + tdx->vp.tdcx_pages = NULL; + +free_tdvpr: + if (tdx->vp.tdvpr_page) + __free_page(tdx->vp.tdvpr_page); + tdx->vp.tdvpr_page = 0; + + return ret; +} + +/* Sometimes reads multipple subleafs. Return how many enties were written. */ +static int tdx_vcpu_get_cpuid_leaf(struct kvm_vcpu *vcpu, u32 leaf, int *entry_index, + struct kvm_cpuid_entry2 *output_e) +{ + int sub_leaf = 0; + int ret; + + /* First try without a subleaf */ + ret = tdx_read_cpuid(vcpu, leaf, 0, false, entry_index, output_e); + + /* If success, or invalid leaf, just give up */ + if (ret != -EIO) + return ret; + + /* + * If the try without a subleaf failed, try reading subleafs until + * failure. The TDX module only supports 6 bits of subleaf index. + */ + while (1) { + /* Keep reading subleafs until there is a failure. */ + if (tdx_read_cpuid(vcpu, leaf, sub_leaf, true, entry_index, output_e)) + return !sub_leaf; + + sub_leaf++; + output_e++; + } + + return 0; +} + +static int tdx_vcpu_get_cpuid(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *cmd) +{ + struct kvm_cpuid2 __user *output, *td_cpuid; + int r = 0, i = 0, leaf; + u32 level; + + output = u64_to_user_ptr(cmd->data); + td_cpuid = kzalloc(sizeof(*td_cpuid) + + sizeof(output->entries[0]) * KVM_MAX_CPUID_ENTRIES, + GFP_KERNEL); + if (!td_cpuid) + return -ENOMEM; + + if (copy_from_user(td_cpuid, output, sizeof(*output))) { + r = -EFAULT; + goto out; + } + + /* Read max CPUID for normal range */ + if (tdx_vcpu_get_cpuid_leaf(vcpu, 0, &i, &td_cpuid->entries[i])) { + r = -EIO; + goto out; + } + level = td_cpuid->entries[0].eax; + + for (leaf = 1; leaf <= level; leaf++) + tdx_vcpu_get_cpuid_leaf(vcpu, leaf, &i, &td_cpuid->entries[i]); + + /* Read max CPUID for extended range */ + if (tdx_vcpu_get_cpuid_leaf(vcpu, 0x80000000, &i, &td_cpuid->entries[i])) { + r = -EIO; + goto out; + } + level = td_cpuid->entries[i - 1].eax; + + for (leaf = 0x80000001; leaf <= level; leaf++) + tdx_vcpu_get_cpuid_leaf(vcpu, leaf, &i, &td_cpuid->entries[i]); + + if (td_cpuid->nent < i) + r = -E2BIG; + td_cpuid->nent = i; + + if (copy_to_user(output, td_cpuid, sizeof(*output))) { + r = -EFAULT; + goto out; + } + + if (r == -E2BIG) + goto out; + + if (copy_to_user(output->entries, td_cpuid->entries, + td_cpuid->nent * sizeof(struct kvm_cpuid_entry2))) + r = -EFAULT; + +out: + kfree(td_cpuid); + + return r; +} + +static int tdx_vcpu_init(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *cmd) +{ + u64 apic_base; + struct vcpu_tdx *tdx = to_tdx(vcpu); + int ret; + + if (cmd->flags) + return -EINVAL; + + if (tdx->state != VCPU_TD_STATE_UNINITIALIZED) + return -EINVAL; + + /* + * TDX requires X2APIC, userspace is responsible for configuring guest + * CPUID accordingly. + */ + apic_base = APIC_DEFAULT_PHYS_BASE | LAPIC_MODE_X2APIC | + (kvm_vcpu_is_reset_bsp(vcpu) ? MSR_IA32_APICBASE_BSP : 0); + if (kvm_apic_set_base(vcpu, apic_base, true)) + return -EINVAL; + + ret = tdx_td_vcpu_init(vcpu, (u64)cmd->data); + if (ret) + return ret; + + td_vmcs_write16(tdx, POSTED_INTR_NV, POSTED_INTR_VECTOR); + td_vmcs_write64(tdx, POSTED_INTR_DESC_ADDR, __pa(&tdx->vt.pi_desc)); + td_vmcs_setbit32(tdx, PIN_BASED_VM_EXEC_CONTROL, PIN_BASED_POSTED_INTR); + + tdx->state = VCPU_TD_STATE_INITIALIZED; + + return 0; +} + +void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) +{ + /* + * Yell on INIT, as TDX doesn't support INIT, i.e. KVM should drop all + * INIT events. + * + * Defer initializing vCPU for RESET state until KVM_TDX_INIT_VCPU, as + * userspace needs to define the vCPU model before KVM can initialize + * vCPU state, e.g. to enable x2APIC. + */ + WARN_ON_ONCE(init_event); +} + +struct tdx_gmem_post_populate_arg { + struct kvm_vcpu *vcpu; + __u32 flags; +}; + +static int tdx_gmem_post_populate(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, + void __user *src, int order, void *_arg) +{ + u64 error_code = PFERR_GUEST_FINAL_MASK | PFERR_PRIVATE_ACCESS; + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + struct tdx_gmem_post_populate_arg *arg = _arg; + struct kvm_vcpu *vcpu = arg->vcpu; + gpa_t gpa = gfn_to_gpa(gfn); + u8 level = PG_LEVEL_4K; + struct page *src_page; + int ret, i; + u64 err, entry, level_state; + + /* + * Get the source page if it has been faulted in. Return failure if the + * source page has been swapped out or unmapped in primary memory. + */ + ret = get_user_pages_fast((unsigned long)src, 1, 0, &src_page); + if (ret < 0) + return ret; + if (ret != 1) + return -ENOMEM; + + ret = kvm_tdp_map_page(vcpu, gpa, error_code, &level); + if (ret < 0) + goto out; + + /* + * The private mem cannot be zapped after kvm_tdp_map_page() + * because all paths are covered by slots_lock and the + * filemap invalidate lock. Check that they are indeed enough. + */ + if (IS_ENABLED(CONFIG_KVM_PROVE_MMU)) { + scoped_guard(read_lock, &kvm->mmu_lock) { + if (KVM_BUG_ON(!kvm_tdp_mmu_gpa_is_mapped(vcpu, gpa), kvm)) { + ret = -EIO; + goto out; + } + } + } + + ret = 0; + err = tdh_mem_page_add(&kvm_tdx->td, gpa, pfn_to_page(pfn), + src_page, &entry, &level_state); + if (err) { + ret = unlikely(tdx_operand_busy(err)) ? -EBUSY : -EIO; + goto out; + } + + if (!KVM_BUG_ON(!atomic64_read(&kvm_tdx->nr_premapped), kvm)) + atomic64_dec(&kvm_tdx->nr_premapped); + + if (arg->flags & KVM_TDX_MEASURE_MEMORY_REGION) { + for (i = 0; i < PAGE_SIZE; i += TDX_EXTENDMR_CHUNKSIZE) { + err = tdh_mr_extend(&kvm_tdx->td, gpa + i, &entry, + &level_state); + if (err) { + ret = -EIO; + break; + } + } + } + +out: + put_page(src_page); + return ret; +} + +static int tdx_vcpu_init_mem_region(struct kvm_vcpu *vcpu, struct kvm_tdx_cmd *cmd) +{ + struct vcpu_tdx *tdx = to_tdx(vcpu); + struct kvm *kvm = vcpu->kvm; + struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm); + struct kvm_tdx_init_mem_region region; + struct tdx_gmem_post_populate_arg arg; + long gmem_ret; + int ret; + + if (tdx->state != VCPU_TD_STATE_INITIALIZED) + return -EINVAL; + + guard(mutex)(&kvm->slots_lock); + + /* Once TD is finalized, the initial guest memory is fixed. */ + if (kvm_tdx->state == TD_STATE_RUNNABLE) + return -EINVAL; + + if (cmd->flags & ~KVM_TDX_MEASURE_MEMORY_REGION) + return -EINVAL; + + if (copy_from_user(®ion, u64_to_user_ptr(cmd->data), sizeof(region))) + return -EFAULT; + + if (!PAGE_ALIGNED(region.source_addr) || !PAGE_ALIGNED(region.gpa) || + !region.nr_pages || + region.gpa + (region.nr_pages << PAGE_SHIFT) <= region.gpa || + !vt_is_tdx_private_gpa(kvm, region.gpa) || + !vt_is_tdx_private_gpa(kvm, region.gpa + (region.nr_pages << PAGE_SHIFT) - 1)) + return -EINVAL; + + kvm_mmu_reload(vcpu); + ret = 0; + while (region.nr_pages) { + if (signal_pending(current)) { + ret = -EINTR; + break; + } + + arg = (struct tdx_gmem_post_populate_arg) { + .vcpu = vcpu, + .flags = cmd->flags, + }; + gmem_ret = kvm_gmem_populate(kvm, gpa_to_gfn(region.gpa), + u64_to_user_ptr(region.source_addr), + 1, tdx_gmem_post_populate, &arg); + if (gmem_ret < 0) { + ret = gmem_ret; + break; + } + + if (gmem_ret != 1) { + ret = -EIO; + break; + } + + region.source_addr += PAGE_SIZE; + region.gpa += PAGE_SIZE; + region.nr_pages--; + + cond_resched(); + } + + if (copy_to_user(u64_to_user_ptr(cmd->data), ®ion, sizeof(region))) + ret = -EFAULT; + return ret; +} + +int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) +{ + struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm); + struct kvm_tdx_cmd cmd; + int ret; + + if (!is_hkid_assigned(kvm_tdx) || kvm_tdx->state == TD_STATE_RUNNABLE) + return -EINVAL; + + if (copy_from_user(&cmd, argp, sizeof(cmd))) + return -EFAULT; + + if (cmd.hw_error) + return -EINVAL; + + switch (cmd.id) { + case KVM_TDX_INIT_VCPU: + ret = tdx_vcpu_init(vcpu, &cmd); + break; + case KVM_TDX_INIT_MEM_REGION: + ret = tdx_vcpu_init_mem_region(vcpu, &cmd); + break; + case KVM_TDX_GET_CPUID: + ret = tdx_vcpu_get_cpuid(vcpu, &cmd); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +int tdx_gmem_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn) +{ + return PG_LEVEL_4K; +} + +static int tdx_online_cpu(unsigned int cpu) +{ + unsigned long flags; + int r; + + /* Sanity check CPU is already in post-VMXON */ + WARN_ON_ONCE(!(cr4_read_shadow() & X86_CR4_VMXE)); + + local_irq_save(flags); + r = tdx_cpu_enable(); + local_irq_restore(flags); + + return r; +} + +static int tdx_offline_cpu(unsigned int cpu) +{ + int i; + + /* No TD is running. Allow any cpu to be offline. */ + if (!atomic_read(&nr_configured_hkid)) + return 0; + + /* + * In order to reclaim TDX HKID, (i.e. when deleting guest TD), need to + * call TDH.PHYMEM.PAGE.WBINVD on all packages to program all memory + * controller with pconfig. If we have active TDX HKID, refuse to + * offline the last online cpu. + */ + for_each_online_cpu(i) { + /* + * Found another online cpu on the same package. + * Allow to offline. + */ + if (i != cpu && topology_physical_package_id(i) == + topology_physical_package_id(cpu)) + return 0; + } + + /* + * This is the last cpu of this package. Don't offline it. + * + * Because it's hard for human operator to understand the + * reason, warn it. + */ +#define MSG_ALLPKG_ONLINE \ + "TDX requires all packages to have an online CPU. Delete all TDs in order to offline all CPUs of a package.\n" + pr_warn_ratelimited(MSG_ALLPKG_ONLINE); + return -EBUSY; +} + +static void __do_tdx_cleanup(void) +{ + /* + * Once TDX module is initialized, it cannot be disabled and + * re-initialized again w/o runtime update (which isn't + * supported by kernel). Only need to remove the cpuhp here. + * The TDX host core code tracks TDX status and can handle + * 'multiple enabling' scenario. + */ + WARN_ON_ONCE(!tdx_cpuhp_state); + cpuhp_remove_state_nocalls_cpuslocked(tdx_cpuhp_state); + tdx_cpuhp_state = 0; +} + +static void __tdx_cleanup(void) +{ + cpus_read_lock(); + __do_tdx_cleanup(); + cpus_read_unlock(); +} + +static int __init __do_tdx_bringup(void) +{ + int r; + + /* + * TDX-specific cpuhp callback to call tdx_cpu_enable() on all + * online CPUs before calling tdx_enable(), and on any new + * going-online CPU to make sure it is ready for TDX guest. + */ + r = cpuhp_setup_state_cpuslocked(CPUHP_AP_ONLINE_DYN, + "kvm/cpu/tdx:online", + tdx_online_cpu, tdx_offline_cpu); + if (r < 0) + return r; + + tdx_cpuhp_state = r; + + r = tdx_enable(); + if (r) + __do_tdx_cleanup(); + + return r; +} + +static int __init __tdx_bringup(void) +{ + const struct tdx_sys_info_td_conf *td_conf; + int r, i; + + for (i = 0; i < ARRAY_SIZE(tdx_uret_msrs); i++) { + /* + * Check if MSRs (tdx_uret_msrs) can be saved/restored + * before returning to user space. + * + * this_cpu_ptr(user_return_msrs)->registered isn't checked + * because the registration is done at vcpu runtime by + * tdx_user_return_msr_update_cache(). + */ + tdx_uret_msrs[i].slot = kvm_find_user_return_msr(tdx_uret_msrs[i].msr); + if (tdx_uret_msrs[i].slot == -1) { + /* If any MSR isn't supported, it is a KVM bug */ + pr_err("MSR %x isn't included by kvm_find_user_return_msr\n", + tdx_uret_msrs[i].msr); + return -EIO; + } + } + + /* + * Enabling TDX requires enabling hardware virtualization first, + * as making SEAMCALLs requires CPU being in post-VMXON state. + */ + r = kvm_enable_virtualization(); + if (r) + return r; + + cpus_read_lock(); + r = __do_tdx_bringup(); + cpus_read_unlock(); + + if (r) + goto tdx_bringup_err; + + /* Get TDX global information for later use */ + tdx_sysinfo = tdx_get_sysinfo(); + if (WARN_ON_ONCE(!tdx_sysinfo)) { + r = -EINVAL; + 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; + + /* + * TDX has its own limit of maximum vCPUs it can support for all + * TDX guests in addition to KVM_MAX_VCPUS. Userspace needs to + * query TDX guest's maximum vCPUs by checking KVM_CAP_MAX_VCPU + * extension on per-VM basis. + * + * TDX module reports such limit via the MAX_VCPU_PER_TD global + * metadata. Different modules may report different values. + * Some old module may also not support this metadata (in which + * case this limit is U16_MAX). + * + * In practice, the reported value reflects the maximum logical + * CPUs that ALL the platforms that the module supports can + * possibly have. + * + * Simply forwarding the MAX_VCPU_PER_TD to userspace could + * result in an unpredictable ABI. KVM instead always advertise + * the number of logical CPUs the platform has as the maximum + * vCPUs for TDX guests. + * + * Make sure MAX_VCPU_PER_TD reported by TDX module is not + * smaller than the number of logical CPUs, otherwise KVM will + * report an unsupported value to userspace. + * + * Note, a platform with TDX enabled in the BIOS cannot support + * physical CPU hotplug, and TDX requires the BIOS has marked + * all logical CPUs in MADT table as enabled. Just use + * num_present_cpus() for the number of logical CPUs. + */ + td_conf = &tdx_sysinfo->td_conf; + if (td_conf->max_vcpus_per_td < num_present_cpus()) { + pr_err("Disable TDX: MAX_VCPU_PER_TD (%u) smaller than number of logical CPUs (%u).\n", + td_conf->max_vcpus_per_td, num_present_cpus()); + r = -EINVAL; + goto get_sysinfo_err; + } + + if (misc_cg_set_capacity(MISC_CG_RES_TDX, tdx_get_nr_guest_keyids())) { + r = -EINVAL; + goto get_sysinfo_err; + } + + /* + * Leave hardware virtualization enabled after TDX is enabled + * successfully. TDX CPU hotplug depends on this. + */ + return 0; + +get_sysinfo_err: + __tdx_cleanup(); +tdx_bringup_err: + kvm_disable_virtualization(); + return r; +} + +void tdx_cleanup(void) +{ + if (enable_tdx) { + misc_cg_set_capacity(MISC_CG_RES_TDX, 0); + __tdx_cleanup(); + kvm_disable_virtualization(); + } +} + +int __init tdx_bringup(void) +{ + int r, i; + + /* tdx_disable_virtualization_cpu() uses associated_tdvcpus. */ + for_each_possible_cpu(i) + INIT_LIST_HEAD(&per_cpu(associated_tdvcpus, i)); + + if (!enable_tdx) + return 0; + + if (!enable_ept) { + pr_err("EPT is required for TDX\n"); + goto success_disable_tdx; + } + + if (!tdp_mmu_enabled || !enable_mmio_caching || !enable_ept_ad_bits) { + pr_err("TDP MMU and MMIO caching and EPT A/D bit is required for TDX\n"); + goto success_disable_tdx; + } + + if (!enable_apicv) { + pr_err("APICv is required for TDX\n"); + goto success_disable_tdx; + } + + if (!cpu_feature_enabled(X86_FEATURE_OSXSAVE)) { + pr_err("tdx: OSXSAVE is required for TDX\n"); + goto success_disable_tdx; + } + + if (!cpu_feature_enabled(X86_FEATURE_MOVDIR64B)) { + pr_err("tdx: MOVDIR64B is required for TDX\n"); + goto success_disable_tdx; + } + + if (!cpu_feature_enabled(X86_FEATURE_SELFSNOOP)) { + pr_err("Self-snoop is required for TDX\n"); + goto success_disable_tdx; + } + + if (!cpu_feature_enabled(X86_FEATURE_TDX_HOST_PLATFORM)) { + pr_err("tdx: no TDX private KeyIDs available\n"); + goto success_disable_tdx; + } + + if (!enable_virt_at_load) { + pr_err("tdx: tdx requires kvm.enable_virt_at_load=1\n"); + goto success_disable_tdx; + } + + /* + * Ideally KVM should probe whether TDX module has been loaded + * first and then try to bring it up. But TDX needs to use SEAMCALL + * to probe whether the module is loaded (there is no CPUID or MSR + * for that), and making SEAMCALL requires enabling virtualization + * first, just like the rest steps of bringing up TDX module. + * + * So, for simplicity do everything in __tdx_bringup(); the first + * SEAMCALL will return -ENODEV when the module is not loaded. The + * only complication is having to make sure that initialization + * SEAMCALLs don't return TDX_SEAMCALL_VMFAILINVALID in other + * cases. + */ + r = __tdx_bringup(); + if (r) { + /* + * Disable TDX only but don't fail to load module if + * the TDX module could not be loaded. No need to print + * message saying "module is not loaded" because it was + * printed when the first SEAMCALL failed. + */ + if (r == -ENODEV) + goto success_disable_tdx; + + enable_tdx = 0; + } + + return r; + +success_disable_tdx: + enable_tdx = 0; + return 0; +} |