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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/xen/enlighten.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r-- | arch/x86/xen/enlighten.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c new file mode 100644 index 000000000..3c61bb98c --- /dev/null +++ b/arch/x86/xen/enlighten.c @@ -0,0 +1,352 @@ +// SPDX-License-Identifier: GPL-2.0 + +#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG +#include <linux/memblock.h> +#endif +#include <linux/console.h> +#include <linux/cpu.h> +#include <linux/kexec.h> +#include <linux/slab.h> +#include <linux/panic_notifier.h> + +#include <xen/xen.h> +#include <xen/features.h> +#include <xen/interface/sched.h> +#include <xen/interface/version.h> +#include <xen/page.h> + +#include <asm/xen/hypercall.h> +#include <asm/xen/hypervisor.h> +#include <asm/cpu.h> +#include <asm/e820/api.h> +#include <asm/setup.h> + +#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. + * Make sure that xen_vcpu_info doesn't cross a page boundary by making it + * cache-line aligned (the struct is guaranteed to have a size of 64 bytes, + * which matches the cache line size of 64-bit x86 processors). + */ +DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); +DEFINE_PER_CPU_ALIGNED(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; + + BUILD_BUG_ON(sizeof(*vcpup) > SMP_CACHE_BYTES); + 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 |