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 0000000000..3c61bb98c1
--- /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