Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 561 insertions, 0 deletions

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
new file mode 100644
index 000000000..70fd21ebb
--- /dev/null
+++ b/arch/x86/hyperv/hv_init.c
@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * X86 specific Hyper-V initialization code.
+ *
+ * Copyright (C) 2016, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/efi.h>
+#include <linux/types.h>
+#include <asm/apic.h>
+#include <asm/desc.h>
+#include <asm/hypervisor.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
+#include <asm/idtentry.h>
+#include <linux/kexec.h>
+#include <linux/version.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/hyperv.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/cpuhotplug.h>
+#include <linux/syscore_ops.h>
+#include <clocksource/hyperv_timer.h>
+
+int hyperv_init_cpuhp;
+
+void *hv_hypercall_pg;
+EXPORT_SYMBOL_GPL(hv_hypercall_pg);
+
+/* Storage to save the hypercall page temporarily for hibernation */
+static void *hv_hypercall_pg_saved;
+
+u32 *hv_vp_index;
+EXPORT_SYMBOL_GPL(hv_vp_index);
+
+struct hv_vp_assist_page **hv_vp_assist_page;
+EXPORT_SYMBOL_GPL(hv_vp_assist_page);
+
+void  __percpu **hyperv_pcpu_input_arg;
+EXPORT_SYMBOL_GPL(hyperv_pcpu_input_arg);
+
+u32 hv_max_vp_index;
+EXPORT_SYMBOL_GPL(hv_max_vp_index);
+
+void *hv_alloc_hyperv_page(void)
+{
+	BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE);
+
+	return (void *)__get_free_page(GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page);
+
+void *hv_alloc_hyperv_zeroed_page(void)
+{
+        BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE);
+
+        return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+}
+EXPORT_SYMBOL_GPL(hv_alloc_hyperv_zeroed_page);
+
+void hv_free_hyperv_page(unsigned long addr)
+{
+	free_page(addr);
+}
+EXPORT_SYMBOL_GPL(hv_free_hyperv_page);
+
+static int hv_cpu_init(unsigned int cpu)
+{
+	u64 msr_vp_index;
+	struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()];
+	void **input_arg;
+	struct page *pg;
+
+	input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+	/* hv_cpu_init() can be called with IRQs disabled from hv_resume() */
+	pg = alloc_page(irqs_disabled() ? GFP_ATOMIC : GFP_KERNEL);
+	if (unlikely(!pg))
+		return -ENOMEM;
+	*input_arg = page_address(pg);
+
+	hv_get_vp_index(msr_vp_index);
+
+	hv_vp_index[smp_processor_id()] = msr_vp_index;
+
+	if (msr_vp_index > hv_max_vp_index)
+		hv_max_vp_index = msr_vp_index;
+
+	if (!hv_vp_assist_page)
+		return 0;
+
+	/*
+	 * The VP ASSIST PAGE is an "overlay" page (see Hyper-V TLFS's Section
+	 * 5.2.1 "GPA Overlay Pages"). Here it must be zeroed out to make sure
+	 * we always write the EOI MSR in hv_apic_eoi_write() *after* the
+	 * EOI optimization is disabled in hv_cpu_die(), otherwise a CPU may
+	 * not be stopped in the case of CPU offlining and the VM will hang.
+	 */
+	if (!*hvp) {
+		*hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO);
+	}
+
+	if (*hvp) {
+		u64 val;
+
+		val = vmalloc_to_pfn(*hvp);
+		val = (val << HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT) |
+			HV_X64_MSR_VP_ASSIST_PAGE_ENABLE;
+
+		wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, val);
+	}
+
+	return 0;
+}
+
+static void (*hv_reenlightenment_cb)(void);
+
+static void hv_reenlightenment_notify(struct work_struct *dummy)
+{
+	struct hv_tsc_emulation_status emu_status;
+
+	rdmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status);
+
+	/* Don't issue the callback if TSC accesses are not emulated */
+	if (hv_reenlightenment_cb && emu_status.inprogress)
+		hv_reenlightenment_cb();
+}
+static DECLARE_DELAYED_WORK(hv_reenlightenment_work, hv_reenlightenment_notify);
+
+void hyperv_stop_tsc_emulation(void)
+{
+	u64 freq;
+	struct hv_tsc_emulation_status emu_status;
+
+	rdmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status);
+	emu_status.inprogress = 0;
+	wrmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status);
+
+	rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
+	tsc_khz = div64_u64(freq, 1000);
+}
+EXPORT_SYMBOL_GPL(hyperv_stop_tsc_emulation);
+
+static inline bool hv_reenlightenment_available(void)
+{
+	/*
+	 * Check for required features and priviliges to make TSC frequency
+	 * change notifications work.
+	 */
+	return ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
+		ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE &&
+		ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT;
+}
+
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_reenlightenment)
+{
+	ack_APIC_irq();
+	inc_irq_stat(irq_hv_reenlightenment_count);
+	schedule_delayed_work(&hv_reenlightenment_work, HZ/10);
+}
+
+void set_hv_tscchange_cb(void (*cb)(void))
+{
+	struct hv_reenlightenment_control re_ctrl = {
+		.vector = HYPERV_REENLIGHTENMENT_VECTOR,
+		.enabled = 1,
+	};
+	struct hv_tsc_emulation_control emu_ctrl = {.enabled = 1};
+
+	if (!hv_reenlightenment_available()) {
+		pr_warn("Hyper-V: reenlightenment support is unavailable\n");
+		return;
+	}
+
+	if (!hv_vp_index)
+		return;
+
+	hv_reenlightenment_cb = cb;
+
+	/* Make sure callback is registered before we write to MSRs */
+	wmb();
+
+	re_ctrl.target_vp = hv_vp_index[get_cpu()];
+
+	wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
+	wrmsrl(HV_X64_MSR_TSC_EMULATION_CONTROL, *((u64 *)&emu_ctrl));
+
+	put_cpu();
+}
+EXPORT_SYMBOL_GPL(set_hv_tscchange_cb);
+
+void clear_hv_tscchange_cb(void)
+{
+	struct hv_reenlightenment_control re_ctrl;
+
+	if (!hv_reenlightenment_available())
+		return;
+
+	rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *(u64 *)&re_ctrl);
+	re_ctrl.enabled = 0;
+	wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *(u64 *)&re_ctrl);
+
+	hv_reenlightenment_cb = NULL;
+}
+EXPORT_SYMBOL_GPL(clear_hv_tscchange_cb);
+
+static int hv_cpu_die(unsigned int cpu)
+{
+	struct hv_reenlightenment_control re_ctrl;
+	unsigned int new_cpu;
+	unsigned long flags;
+	void **input_arg;
+	void *input_pg = NULL;
+
+	local_irq_save(flags);
+	input_arg = (void **)this_cpu_ptr(hyperv_pcpu_input_arg);
+	input_pg = *input_arg;
+	*input_arg = NULL;
+	local_irq_restore(flags);
+	free_page((unsigned long)input_pg);
+
+	if (hv_vp_assist_page && hv_vp_assist_page[cpu])
+		wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, 0);
+
+	if (hv_reenlightenment_cb == NULL)
+		return 0;
+
+	rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
+	if (re_ctrl.target_vp == hv_vp_index[cpu]) {
+		/*
+		 * Reassign reenlightenment notifications to some other online
+		 * CPU or just disable the feature if there are no online CPUs
+		 * left (happens on hibernation).
+		 */
+		new_cpu = cpumask_any_but(cpu_online_mask, cpu);
+
+		if (new_cpu < nr_cpu_ids)
+			re_ctrl.target_vp = hv_vp_index[new_cpu];
+		else
+			re_ctrl.enabled = 0;
+
+		wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl));
+	}
+
+	return 0;
+}
+
+static int __init hv_pci_init(void)
+{
+	int gen2vm = efi_enabled(EFI_BOOT);
+
+	/*
+	 * For Generation-2 VM, we exit from pci_arch_init() by returning 0.
+	 * The purpose is to suppress the harmless warning:
+	 * "PCI: Fatal: No config space access function found"
+	 */
+	if (gen2vm)
+		return 0;
+
+	/* For Generation-1 VM, we'll proceed in pci_arch_init().  */
+	return 1;
+}
+
+static int hv_suspend(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+	int ret;
+
+	/*
+	 * Reset the hypercall page as it is going to be invalidated
+	 * accross hibernation. Setting hv_hypercall_pg to NULL ensures
+	 * that any subsequent hypercall operation fails safely instead of
+	 * crashing due to an access of an invalid page. The hypercall page
+	 * pointer is restored on resume.
+	 */
+	hv_hypercall_pg_saved = hv_hypercall_pg;
+	hv_hypercall_pg = NULL;
+
+	/* Disable the hypercall page in the hypervisor */
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 0;
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	ret = hv_cpu_die(0);
+	return ret;
+}
+
+static void hv_resume(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+	int ret;
+
+	ret = hv_cpu_init(0);
+	WARN_ON(ret);
+
+	/* Re-enable the hypercall page */
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 1;
+	hypercall_msr.guest_physical_address =
+		vmalloc_to_pfn(hv_hypercall_pg_saved);
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	hv_hypercall_pg = hv_hypercall_pg_saved;
+	hv_hypercall_pg_saved = NULL;
+
+	/*
+	 * Reenlightenment notifications are disabled by hv_cpu_die(0),
+	 * reenable them here if hv_reenlightenment_cb was previously set.
+	 */
+	if (hv_reenlightenment_cb)
+		set_hv_tscchange_cb(hv_reenlightenment_cb);
+}
+
+/* Note: when the ops are called, only CPU0 is online and IRQs are disabled. */
+static struct syscore_ops hv_syscore_ops = {
+	.suspend	= hv_suspend,
+	.resume		= hv_resume,
+};
+
+static void (* __initdata old_setup_percpu_clockev)(void);
+
+static void __init hv_stimer_setup_percpu_clockev(void)
+{
+	/*
+	 * Ignore any errors in setting up stimer clockevents
+	 * as we can run with the LAPIC timer as a fallback.
+	 */
+	(void)hv_stimer_alloc();
+
+	/*
+	 * Still register the LAPIC timer, because the direct-mode STIMER is
+	 * not supported by old versions of Hyper-V. This also allows users
+	 * to switch to LAPIC timer via /sys, if they want to.
+	 */
+	if (old_setup_percpu_clockev)
+		old_setup_percpu_clockev();
+}
+
+/*
+ * This function is to be invoked early in the boot sequence after the
+ * hypervisor has been detected.
+ *
+ * 1. Setup the hypercall page.
+ * 2. Register Hyper-V specific clocksource.
+ * 3. Setup Hyper-V specific APIC entry points.
+ */
+void __init hyperv_init(void)
+{
+	u64 guest_id, required_msrs;
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+	int cpuhp, i;
+
+	if (x86_hyper_type != X86_HYPER_MS_HYPERV)
+		return;
+
+	/* Absolutely required MSRs */
+	required_msrs = HV_MSR_HYPERCALL_AVAILABLE |
+		HV_MSR_VP_INDEX_AVAILABLE;
+
+	if ((ms_hyperv.features & required_msrs) != required_msrs)
+		return;
+
+	/*
+	 * Allocate the per-CPU state for the hypercall input arg.
+	 * If this allocation fails, we will not be able to setup
+	 * (per-CPU) hypercall input page and thus this failure is
+	 * fatal on Hyper-V.
+	 */
+	hyperv_pcpu_input_arg = alloc_percpu(void  *);
+
+	BUG_ON(hyperv_pcpu_input_arg == NULL);
+
+	/* Allocate percpu VP index */
+	hv_vp_index = kmalloc_array(num_possible_cpus(), sizeof(*hv_vp_index),
+				    GFP_KERNEL);
+	if (!hv_vp_index)
+		return;
+
+	for (i = 0; i < num_possible_cpus(); i++)
+		hv_vp_index[i] = VP_INVAL;
+
+	hv_vp_assist_page = kcalloc(num_possible_cpus(),
+				    sizeof(*hv_vp_assist_page), GFP_KERNEL);
+	if (!hv_vp_assist_page) {
+		ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED;
+		goto free_vp_index;
+	}
+
+	cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
+				  hv_cpu_init, hv_cpu_die);
+	if (cpuhp < 0)
+		goto free_vp_assist_page;
+
+	/*
+	 * Setup the hypercall page and enable hypercalls.
+	 * 1. Register the guest ID
+	 * 2. Enable the hypercall and register the hypercall page
+	 */
+	guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
+	wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+	hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START,
+			VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX,
+			VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
+			__builtin_return_address(0));
+	if (hv_hypercall_pg == NULL) {
+		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+		goto remove_cpuhp_state;
+	}
+
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 1;
+	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	/*
+	 * hyperv_init() is called before LAPIC is initialized: see
+	 * apic_intr_mode_init() -> x86_platform.apic_post_init() and
+	 * apic_bsp_setup() -> setup_local_APIC(). The direct-mode STIMER
+	 * depends on LAPIC, so hv_stimer_alloc() should be called from
+	 * x86_init.timers.setup_percpu_clockev.
+	 */
+	old_setup_percpu_clockev = x86_init.timers.setup_percpu_clockev;
+	x86_init.timers.setup_percpu_clockev = hv_stimer_setup_percpu_clockev;
+
+	hv_apic_init();
+
+	x86_init.pci.arch_init = hv_pci_init;
+
+	register_syscore_ops(&hv_syscore_ops);
+
+	hyperv_init_cpuhp = cpuhp;
+	return;
+
+remove_cpuhp_state:
+	cpuhp_remove_state(cpuhp);
+free_vp_assist_page:
+	kfree(hv_vp_assist_page);
+	hv_vp_assist_page = NULL;
+free_vp_index:
+	kfree(hv_vp_index);
+	hv_vp_index = NULL;
+}
+
+/*
+ * This routine is called before kexec/kdump, it does the required cleanup.
+ */
+void hyperv_cleanup(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+
+	/* Reset our OS id */
+	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+
+	/*
+	 * Reset hypercall page reference before reset the page,
+	 * let hypercall operations fail safely rather than
+	 * panic the kernel for using invalid hypercall page
+	 */
+	hv_hypercall_pg = NULL;
+
+	/* Reset the hypercall page */
+	hypercall_msr.as_uint64 = 0;
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	/* Reset the TSC page */
+	hypercall_msr.as_uint64 = 0;
+	wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
+}
+EXPORT_SYMBOL_GPL(hyperv_cleanup);
+
+void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
+{
+	static bool panic_reported;
+	u64 guest_id;
+
+	if (in_die && !panic_on_oops)
+		return;
+
+	/*
+	 * We prefer to report panic on 'die' chain as we have proper
+	 * registers to report, but if we miss it (e.g. on BUG()) we need
+	 * to report it on 'panic'.
+	 */
+	if (panic_reported)
+		return;
+	panic_reported = true;
+
+	rdmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+	wrmsrl(HV_X64_MSR_CRASH_P0, err);
+	wrmsrl(HV_X64_MSR_CRASH_P1, guest_id);
+	wrmsrl(HV_X64_MSR_CRASH_P2, regs->ip);
+	wrmsrl(HV_X64_MSR_CRASH_P3, regs->ax);
+	wrmsrl(HV_X64_MSR_CRASH_P4, regs->sp);
+
+	/*
+	 * Let Hyper-V know there is crash data available
+	 */
+	wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
+}
+EXPORT_SYMBOL_GPL(hyperv_report_panic);
+
+/**
+ * hyperv_report_panic_msg - report panic message to Hyper-V
+ * @pa: physical address of the panic page containing the message
+ * @size: size of the message in the page
+ */
+void hyperv_report_panic_msg(phys_addr_t pa, size_t size)
+{
+	/*
+	 * P3 to contain the physical address of the panic page & P4 to
+	 * contain the size of the panic data in that page. Rest of the
+	 * registers are no-op when the NOTIFY_MSG flag is set.
+	 */
+	wrmsrl(HV_X64_MSR_CRASH_P0, 0);
+	wrmsrl(HV_X64_MSR_CRASH_P1, 0);
+	wrmsrl(HV_X64_MSR_CRASH_P2, 0);
+	wrmsrl(HV_X64_MSR_CRASH_P3, pa);
+	wrmsrl(HV_X64_MSR_CRASH_P4, size);
+
+	/*
+	 * Let Hyper-V know there is crash data available along with
+	 * the panic message.
+	 */
+	wrmsrl(HV_X64_MSR_CRASH_CTL,
+	       (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG));
+}
+EXPORT_SYMBOL_GPL(hyperv_report_panic_msg);
+
+bool hv_is_hyperv_initialized(void)
+{
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+
+	/*
+	 * Ensure that we're really on Hyper-V, and not a KVM or Xen
+	 * emulation of Hyper-V
+	 */
+	if (x86_hyper_type != X86_HYPER_MS_HYPERV)
+		return false;
+
+	/*
+	 * Verify that earlier initialization succeeded by checking
+	 * that the hypercall page is setup
+	 */
+	hypercall_msr.as_uint64 = 0;
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+	return hypercall_msr.enable;
+}
+EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
+
+bool hv_is_hibernation_supported(void)
+{
+	return acpi_sleep_state_supported(ACPI_STATE_S4);
+}
+EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);