// SPDX-License-Identifier: GPL-2.0 #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "xen-ops.h" #include "smp.h" #include "pmu.h" EXPORT_SYMBOL_GPL(hypercall_page); /* * Pointer to the xen_vcpu_info structure or * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info * but during boot it is switched to point to xen_vcpu_info. * The pointer is used in __xen_evtchn_do_upcall to acknowledge pending events. */ DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); /* Linux <-> Xen vCPU id mapping */ DEFINE_PER_CPU(uint32_t, xen_vcpu_id); EXPORT_PER_CPU_SYMBOL(xen_vcpu_id); unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; EXPORT_SYMBOL(machine_to_phys_mapping); unsigned long machine_to_phys_nr; EXPORT_SYMBOL(machine_to_phys_nr); struct start_info *xen_start_info; EXPORT_SYMBOL_GPL(xen_start_info); struct shared_info xen_dummy_shared_info; __read_mostly bool xen_have_vector_callback = true; EXPORT_SYMBOL_GPL(xen_have_vector_callback); /* * NB: These need to live in .data or alike because they're used by * xen_prepare_pvh() which runs before clearing the bss. */ enum xen_domain_type __ro_after_init xen_domain_type = XEN_NATIVE; EXPORT_SYMBOL_GPL(xen_domain_type); uint32_t __ro_after_init xen_start_flags; EXPORT_SYMBOL(xen_start_flags); /* * Point at some empty memory to start with. We map the real shared_info * page as soon as fixmap is up and running. */ struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info; static int xen_cpu_up_online(unsigned int cpu) { xen_init_lock_cpu(cpu); return 0; } int xen_cpuhp_setup(int (*cpu_up_prepare_cb)(unsigned int), int (*cpu_dead_cb)(unsigned int)) { int rc; rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE, "x86/xen/guest:prepare", cpu_up_prepare_cb, cpu_dead_cb); if (rc >= 0) { rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/xen/guest:online", xen_cpu_up_online, NULL); if (rc < 0) cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE); } return rc >= 0 ? 0 : rc; } static void xen_vcpu_setup_restore(int cpu) { /* Any per_cpu(xen_vcpu) is stale, so reset it */ xen_vcpu_info_reset(cpu); /* * For PVH and PVHVM, setup online VCPUs only. The rest will * be handled by hotplug. */ if (xen_pv_domain() || (xen_hvm_domain() && cpu_online(cpu))) xen_vcpu_setup(cpu); } /* * On restore, set the vcpu placement up again. * If it fails, then we're in a bad state, since * we can't back out from using it... */ void xen_vcpu_restore(void) { int cpu; for_each_possible_cpu(cpu) { bool other_cpu = (cpu != smp_processor_id()); bool is_up; if (xen_vcpu_nr(cpu) == XEN_VCPU_ID_INVALID) continue; /* Only Xen 4.5 and higher support this. */ is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu), NULL) > 0; if (other_cpu && is_up && HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL)) BUG(); if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock)) xen_setup_runstate_info(cpu); xen_vcpu_setup_restore(cpu); if (other_cpu && is_up && HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL)) BUG(); } } void xen_vcpu_info_reset(int cpu) { if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS) { per_cpu(xen_vcpu, cpu) = &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)]; } else { /* Set to NULL so that if somebody accesses it we get an OOPS */ per_cpu(xen_vcpu, cpu) = NULL; } } void xen_vcpu_setup(int cpu) { struct vcpu_register_vcpu_info info; int err; struct vcpu_info *vcpup; BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); /* * This path is called on PVHVM at bootup (xen_hvm_smp_prepare_boot_cpu) * and at restore (xen_vcpu_restore). Also called for hotplugged * VCPUs (cpu_init -> xen_hvm_cpu_prepare_hvm). * However, the hypercall can only be done once (see below) so if a VCPU * is offlined and comes back online then let's not redo the hypercall. * * For PV it is called during restore (xen_vcpu_restore) and bootup * (xen_setup_vcpu_info_placement). The hotplug mechanism does not * use this function. */ if (xen_hvm_domain()) { if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu)) return; } vcpup = &per_cpu(xen_vcpu_info, cpu); info.mfn = arbitrary_virt_to_mfn(vcpup); info.offset = offset_in_page(vcpup); /* * N.B. This hypercall can _only_ be called once per CPU. * Subsequent calls will error out with -EINVAL. This is due to * the fact that hypervisor has no unregister variant and this * hypercall does not allow to over-write info.mfn and * info.offset. */ err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu), &info); if (err) panic("register_vcpu_info failed: cpu=%d err=%d\n", cpu, err); per_cpu(xen_vcpu, cpu) = vcpup; } void __init xen_banner(void) { unsigned version = HYPERVISOR_xen_version(XENVER_version, NULL); struct xen_extraversion extra; HYPERVISOR_xen_version(XENVER_extraversion, &extra); pr_info("Booting kernel on %s\n", pv_info.name); pr_info("Xen version: %u.%u%s%s\n", version >> 16, version & 0xffff, extra.extraversion, xen_feature(XENFEAT_mmu_pt_update_preserve_ad) ? " (preserve-AD)" : ""); } /* Check if running on Xen version (major, minor) or later */ bool xen_running_on_version_or_later(unsigned int major, unsigned int minor) { unsigned int version; if (!xen_domain()) return false; version = HYPERVISOR_xen_version(XENVER_version, NULL); if ((((version >> 16) == major) && ((version & 0xffff) >= minor)) || ((version >> 16) > major)) return true; return false; } void __init xen_add_preferred_consoles(void) { add_preferred_console("xenboot", 0, NULL); if (!boot_params.screen_info.orig_video_isVGA) add_preferred_console("tty", 0, NULL); add_preferred_console("hvc", 0, NULL); if (boot_params.screen_info.orig_video_isVGA) add_preferred_console("tty", 0, NULL); } void xen_reboot(int reason) { struct sched_shutdown r = { .reason = reason }; int cpu; for_each_online_cpu(cpu) xen_pmu_finish(cpu); if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) BUG(); } static int reboot_reason = SHUTDOWN_reboot; static bool xen_legacy_crash; void xen_emergency_restart(void) { xen_reboot(reboot_reason); } static int xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr) { if (!kexec_crash_loaded()) { if (xen_legacy_crash) xen_reboot(SHUTDOWN_crash); reboot_reason = SHUTDOWN_crash; /* * If panic_timeout==0 then we are supposed to wait forever. * However, to preserve original dom0 behavior we have to drop * into hypervisor. (domU behavior is controlled by its * config file) */ if (panic_timeout == 0) panic_timeout = -1; } return NOTIFY_DONE; } static int __init parse_xen_legacy_crash(char *arg) { xen_legacy_crash = true; return 0; } early_param("xen_legacy_crash", parse_xen_legacy_crash); static struct notifier_block xen_panic_block = { .notifier_call = xen_panic_event, .priority = INT_MIN }; int xen_panic_handler_init(void) { atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block); return 0; } void xen_pin_vcpu(int cpu) { static bool disable_pinning; struct sched_pin_override pin_override; int ret; if (disable_pinning) return; pin_override.pcpu = cpu; ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override); /* Ignore errors when removing override. */ if (cpu < 0) return; switch (ret) { case -ENOSYS: pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n", cpu); disable_pinning = true; break; case -EPERM: WARN(1, "Trying to pin vcpu without having privilege to do so\n"); disable_pinning = true; break; case -EINVAL: case -EBUSY: pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n", cpu); break; case 0: break; default: WARN(1, "rc %d while trying to pin vcpu\n", ret); disable_pinning = true; } } #ifdef CONFIG_HOTPLUG_CPU void xen_arch_register_cpu(int num) { arch_register_cpu(num); } EXPORT_SYMBOL(xen_arch_register_cpu); void xen_arch_unregister_cpu(int num) { arch_unregister_cpu(num); } EXPORT_SYMBOL(xen_arch_unregister_cpu); #endif