diff options
Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
| -rw-r--r-- | arch/x86/kvm/svm/sev.c | 121 |
1 files changed, 71 insertions, 50 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 17b53457d866..75fa6dd268f0 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -258,6 +258,7 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp) goto e_free; INIT_LIST_HEAD(&sev->regions_list); + INIT_LIST_HEAD(&sev->mirror_vms); return 0; @@ -1623,9 +1624,12 @@ static void sev_unlock_vcpus_for_migration(struct kvm *kvm) } } -static void sev_migrate_from(struct kvm_sev_info *dst, - struct kvm_sev_info *src) +static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm) { + struct kvm_sev_info *dst = &to_kvm_svm(dst_kvm)->sev_info; + struct kvm_sev_info *src = &to_kvm_svm(src_kvm)->sev_info; + struct kvm_sev_info *mirror; + dst->active = true; dst->asid = src->asid; dst->handle = src->handle; @@ -1639,6 +1643,30 @@ static void sev_migrate_from(struct kvm_sev_info *dst, src->enc_context_owner = NULL; list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list); + + /* + * If this VM has mirrors, "transfer" each mirror's refcount of the + * source to the destination (this KVM). The caller holds a reference + * to the source, so there's no danger of use-after-free. + */ + list_cut_before(&dst->mirror_vms, &src->mirror_vms, &src->mirror_vms); + list_for_each_entry(mirror, &dst->mirror_vms, mirror_entry) { + kvm_get_kvm(dst_kvm); + kvm_put_kvm(src_kvm); + mirror->enc_context_owner = dst_kvm; + } + + /* + * If this VM is a mirror, remove the old mirror from the owners list + * and add the new mirror to the list. + */ + if (is_mirroring_enc_context(dst_kvm)) { + struct kvm_sev_info *owner_sev_info = + &to_kvm_svm(dst->enc_context_owner)->sev_info; + + list_del(&src->mirror_entry); + list_add_tail(&dst->mirror_entry, &owner_sev_info->mirror_vms); + } } static int sev_es_migrate_from(struct kvm *dst, struct kvm *src) @@ -1681,7 +1709,7 @@ static int sev_es_migrate_from(struct kvm *dst, struct kvm *src) return 0; } -int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) +int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd) { struct kvm_sev_info *dst_sev = &to_kvm_svm(kvm)->sev_info; struct kvm_sev_info *src_sev, *cg_cleanup_sev; @@ -1708,15 +1736,6 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) src_sev = &to_kvm_svm(source_kvm)->sev_info; - /* - * VMs mirroring src's encryption context rely on it to keep the - * ASID allocated, but below we are clearing src_sev->asid. - */ - if (src_sev->num_mirrored_vms) { - ret = -EBUSY; - goto out_unlock; - } - dst_sev->misc_cg = get_current_misc_cg(); cg_cleanup_sev = dst_sev; if (dst_sev->misc_cg != src_sev->misc_cg) { @@ -1738,7 +1757,8 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd) if (ret) goto out_source_vcpu; } - sev_migrate_from(dst_sev, src_sev); + + sev_migrate_from(kvm, source_kvm); kvm_vm_dead(source_kvm); cg_cleanup_sev = src_sev; ret = 0; @@ -1761,7 +1781,7 @@ out_fput: return ret; } -int svm_mem_enc_op(struct kvm *kvm, void __user *argp) +int sev_mem_enc_ioctl(struct kvm *kvm, void __user *argp) { struct kvm_sev_cmd sev_cmd; int r; @@ -1858,8 +1878,8 @@ out: return r; } -int svm_register_enc_region(struct kvm *kvm, - struct kvm_enc_region *range) +int sev_mem_enc_register_region(struct kvm *kvm, + struct kvm_enc_region *range) { struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info; struct enc_region *region; @@ -1932,8 +1952,8 @@ static void __unregister_enc_region_locked(struct kvm *kvm, kfree(region); } -int svm_unregister_enc_region(struct kvm *kvm, - struct kvm_enc_region *range) +int sev_mem_enc_unregister_region(struct kvm *kvm, + struct kvm_enc_region *range) { struct enc_region *region; int ret; @@ -1972,7 +1992,7 @@ failed: return ret; } -int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd) +int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd) { struct file *source_kvm_file; struct kvm *source_kvm; @@ -2008,10 +2028,10 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd) */ source_sev = &to_kvm_svm(source_kvm)->sev_info; kvm_get_kvm(source_kvm); - source_sev->num_mirrored_vms++; + mirror_sev = &to_kvm_svm(kvm)->sev_info; + list_add_tail(&mirror_sev->mirror_entry, &source_sev->mirror_vms); /* Set enc_context_owner and copy its encryption context over */ - mirror_sev = &to_kvm_svm(kvm)->sev_info; mirror_sev->enc_context_owner = source_kvm; mirror_sev->active = true; mirror_sev->asid = source_sev->asid; @@ -2019,6 +2039,7 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd) mirror_sev->es_active = source_sev->es_active; mirror_sev->handle = source_sev->handle; INIT_LIST_HEAD(&mirror_sev->regions_list); + INIT_LIST_HEAD(&mirror_sev->mirror_vms); ret = 0; /* @@ -2041,19 +2062,17 @@ void sev_vm_destroy(struct kvm *kvm) struct list_head *head = &sev->regions_list; struct list_head *pos, *q; - WARN_ON(sev->num_mirrored_vms); - if (!sev_guest(kvm)) return; + WARN_ON(!list_empty(&sev->mirror_vms)); + /* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */ if (is_mirroring_enc_context(kvm)) { struct kvm *owner_kvm = sev->enc_context_owner; - struct kvm_sev_info *owner_sev = &to_kvm_svm(owner_kvm)->sev_info; mutex_lock(&owner_kvm->lock); - if (!WARN_ON(!owner_sev->num_mirrored_vms)) - owner_sev->num_mirrored_vms--; + list_del(&sev->mirror_entry); mutex_unlock(&owner_kvm->lock); kvm_put_kvm(owner_kvm); return; @@ -2173,7 +2192,7 @@ out: #endif } -void sev_hardware_teardown(void) +void sev_hardware_unsetup(void) { if (!sev_enabled) return; @@ -2358,7 +2377,7 @@ static void sev_es_sync_from_ghcb(struct vcpu_svm *svm) memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap)); } -static bool sev_es_validate_vmgexit(struct vcpu_svm *svm) +static int sev_es_validate_vmgexit(struct vcpu_svm *svm) { struct kvm_vcpu *vcpu; struct ghcb *ghcb; @@ -2463,7 +2482,7 @@ static bool sev_es_validate_vmgexit(struct vcpu_svm *svm) goto vmgexit_err; } - return true; + return 0; vmgexit_err: vcpu = &svm->vcpu; @@ -2486,7 +2505,8 @@ vmgexit_err: ghcb_set_sw_exit_info_1(ghcb, 2); ghcb_set_sw_exit_info_2(ghcb, reason); - return false; + /* Resume the guest to "return" the error code. */ + return 1; } void sev_es_unmap_ghcb(struct vcpu_svm *svm) @@ -2545,7 +2565,7 @@ void pre_sev_run(struct vcpu_svm *svm, int cpu) } #define GHCB_SCRATCH_AREA_LIMIT (16ULL * PAGE_SIZE) -static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) +static int setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) { struct vmcb_control_area *control = &svm->vmcb->control; struct ghcb *ghcb = svm->sev_es.ghcb; @@ -2598,14 +2618,14 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) } scratch_va = kvzalloc(len, GFP_KERNEL_ACCOUNT); if (!scratch_va) - goto e_scratch; + return -ENOMEM; if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) { /* Unable to copy scratch area from guest */ pr_err("vmgexit: kvm_read_guest for scratch area failed\n"); kvfree(scratch_va); - goto e_scratch; + return -EFAULT; } /* @@ -2621,13 +2641,13 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len) svm->sev_es.ghcb_sa = scratch_va; svm->sev_es.ghcb_sa_len = len; - return true; + return 0; e_scratch: ghcb_set_sw_exit_info_1(ghcb, 2); ghcb_set_sw_exit_info_2(ghcb, GHCB_ERR_INVALID_SCRATCH_AREA); - return false; + return 1; } static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask, @@ -2765,17 +2785,18 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) exit_code = ghcb_get_sw_exit_code(ghcb); - if (!sev_es_validate_vmgexit(svm)) - return 1; + ret = sev_es_validate_vmgexit(svm); + if (ret) + return ret; sev_es_sync_from_ghcb(svm); ghcb_set_sw_exit_info_1(ghcb, 0); ghcb_set_sw_exit_info_2(ghcb, 0); - ret = 1; switch (exit_code) { case SVM_VMGEXIT_MMIO_READ: - if (!setup_vmgexit_scratch(svm, true, control->exit_info_2)) + ret = setup_vmgexit_scratch(svm, true, control->exit_info_2); + if (ret) break; ret = kvm_sev_es_mmio_read(vcpu, @@ -2784,7 +2805,8 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) svm->sev_es.ghcb_sa); break; case SVM_VMGEXIT_MMIO_WRITE: - if (!setup_vmgexit_scratch(svm, false, control->exit_info_2)) + ret = setup_vmgexit_scratch(svm, false, control->exit_info_2); + if (ret) break; ret = kvm_sev_es_mmio_write(vcpu, @@ -2817,6 +2839,7 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu) ghcb_set_sw_exit_info_2(ghcb, GHCB_ERR_INVALID_INPUT); } + ret = 1; break; } case SVM_VMGEXIT_UNSUPPORTED_EVENT: @@ -2836,6 +2859,7 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in) { int count; int bytes; + int r; if (svm->vmcb->control.exit_info_2 > INT_MAX) return -EINVAL; @@ -2844,8 +2868,9 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in) if (unlikely(check_mul_overflow(count, size, &bytes))) return -EINVAL; - if (!setup_vmgexit_scratch(svm, in, bytes)) - return 1; + r = setup_vmgexit_scratch(svm, in, bytes); + if (r) + return r; return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->sev_es.ghcb_sa, count, in); @@ -2907,20 +2932,16 @@ void sev_es_vcpu_reset(struct vcpu_svm *svm) sev_enc_bit)); } -void sev_es_prepare_guest_switch(struct vcpu_svm *svm, unsigned int cpu) +void sev_es_prepare_switch_to_guest(struct vmcb_save_area *hostsa) { - struct svm_cpu_data *sd = per_cpu(svm_data, cpu); - struct vmcb_save_area *hostsa; - /* * As an SEV-ES guest, hardware will restore the host state on VMEXIT, - * of which one step is to perform a VMLOAD. Since hardware does not - * perform a VMSAVE on VMRUN, the host savearea must be updated. + * of which one step is to perform a VMLOAD. KVM performs the + * corresponding VMSAVE in svm_prepare_guest_switch for both + * traditional and SEV-ES guests. */ - vmsave(__sme_page_pa(sd->save_area)); /* XCR0 is restored on VMEXIT, save the current host value */ - hostsa = (struct vmcb_save_area *)(page_address(sd->save_area) + 0x400); hostsa->xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); /* PKRU is restored on VMEXIT, save the current host value */ |