Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 502 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
new file mode 100644
index 000000000..34d9e899e
--- /dev/null
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -0,0 +1,502 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * HyperV  Detection code.
+ *
+ * Copyright (C) 2010, Novell, Inc.
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
+ */
+
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/hardirq.h>
+#include <linux/efi.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kexec.h>
+#include <linux/i8253.h>
+#include <linux/random.h>
+#include <linux/swiotlb.h>
+#include <asm/processor.h>
+#include <asm/hypervisor.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
+#include <asm/desc.h>
+#include <asm/idtentry.h>
+#include <asm/irq_regs.h>
+#include <asm/i8259.h>
+#include <asm/apic.h>
+#include <asm/timer.h>
+#include <asm/reboot.h>
+#include <asm/nmi.h>
+#include <clocksource/hyperv_timer.h>
+#include <asm/numa.h>
+#include <asm/coco.h>
+
+/* Is Linux running as the root partition? */
+bool hv_root_partition;
+struct ms_hyperv_info ms_hyperv;
+
+#if IS_ENABLED(CONFIG_HYPERV)
+static void (*vmbus_handler)(void);
+static void (*hv_stimer0_handler)(void);
+static void (*hv_kexec_handler)(void);
+static void (*hv_crash_handler)(struct pt_regs *regs);
+
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_callback)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	inc_irq_stat(irq_hv_callback_count);
+	if (vmbus_handler)
+		vmbus_handler();
+
+	if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED)
+		ack_APIC_irq();
+
+	set_irq_regs(old_regs);
+}
+
+void hv_setup_vmbus_handler(void (*handler)(void))
+{
+	vmbus_handler = handler;
+}
+
+void hv_remove_vmbus_handler(void)
+{
+	/* We have no way to deallocate the interrupt gate */
+	vmbus_handler = NULL;
+}
+
+/*
+ * Routines to do per-architecture handling of stimer0
+ * interrupts when in Direct Mode
+ */
+DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_stimer0)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	inc_irq_stat(hyperv_stimer0_count);
+	if (hv_stimer0_handler)
+		hv_stimer0_handler();
+	add_interrupt_randomness(HYPERV_STIMER0_VECTOR);
+	ack_APIC_irq();
+
+	set_irq_regs(old_regs);
+}
+
+/* For x86/x64, override weak placeholders in hyperv_timer.c */
+void hv_setup_stimer0_handler(void (*handler)(void))
+{
+	hv_stimer0_handler = handler;
+}
+
+void hv_remove_stimer0_handler(void)
+{
+	/* We have no way to deallocate the interrupt gate */
+	hv_stimer0_handler = NULL;
+}
+
+void hv_setup_kexec_handler(void (*handler)(void))
+{
+	hv_kexec_handler = handler;
+}
+
+void hv_remove_kexec_handler(void)
+{
+	hv_kexec_handler = NULL;
+}
+
+void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
+{
+	hv_crash_handler = handler;
+}
+
+void hv_remove_crash_handler(void)
+{
+	hv_crash_handler = NULL;
+}
+
+#ifdef CONFIG_KEXEC_CORE
+static void hv_machine_shutdown(void)
+{
+	if (kexec_in_progress && hv_kexec_handler)
+		hv_kexec_handler();
+
+	/*
+	 * Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor
+	 * corrupts the old VP Assist Pages and can crash the kexec kernel.
+	 */
+	if (kexec_in_progress && hyperv_init_cpuhp > 0)
+		cpuhp_remove_state(hyperv_init_cpuhp);
+
+	/* The function calls stop_other_cpus(). */
+	native_machine_shutdown();
+
+	/* Disable the hypercall page when there is only 1 active CPU. */
+	if (kexec_in_progress)
+		hyperv_cleanup();
+}
+
+static void hv_machine_crash_shutdown(struct pt_regs *regs)
+{
+	if (hv_crash_handler)
+		hv_crash_handler(regs);
+
+	/* The function calls crash_smp_send_stop(). */
+	native_machine_crash_shutdown(regs);
+
+	/* Disable the hypercall page when there is only 1 active CPU. */
+	hyperv_cleanup();
+}
+#endif /* CONFIG_KEXEC_CORE */
+#endif /* CONFIG_HYPERV */
+
+static uint32_t  __init ms_hyperv_platform(void)
+{
+	u32 eax;
+	u32 hyp_signature[3];
+
+	if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
+		return 0;
+
+	cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS,
+	      &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]);
+
+	if (eax < HYPERV_CPUID_MIN || eax > HYPERV_CPUID_MAX ||
+	    memcmp("Microsoft Hv", hyp_signature, 12))
+		return 0;
+
+	/* HYPERCALL and VP_INDEX MSRs are mandatory for all features. */
+	eax = cpuid_eax(HYPERV_CPUID_FEATURES);
+	if (!(eax & HV_MSR_HYPERCALL_AVAILABLE)) {
+		pr_warn("x86/hyperv: HYPERCALL MSR not available.\n");
+		return 0;
+	}
+	if (!(eax & HV_MSR_VP_INDEX_AVAILABLE)) {
+		pr_warn("x86/hyperv: VP_INDEX MSR not available.\n");
+		return 0;
+	}
+
+	return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS;
+}
+
+static unsigned char hv_get_nmi_reason(void)
+{
+	return 0;
+}
+
+#ifdef CONFIG_X86_LOCAL_APIC
+/*
+ * Prior to WS2016 Debug-VM sends NMIs to all CPUs which makes
+ * it difficult to process CHANNELMSG_UNLOAD in case of crash. Handle
+ * unknown NMI on the first CPU which gets it.
+ */
+static int hv_nmi_unknown(unsigned int val, struct pt_regs *regs)
+{
+	static atomic_t nmi_cpu = ATOMIC_INIT(-1);
+
+	if (!unknown_nmi_panic)
+		return NMI_DONE;
+
+	if (atomic_cmpxchg(&nmi_cpu, -1, raw_smp_processor_id()) != -1)
+		return NMI_HANDLED;
+
+	return NMI_DONE;
+}
+#endif
+
+static unsigned long hv_get_tsc_khz(void)
+{
+	unsigned long freq;
+
+	rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq);
+
+	return freq / 1000;
+}
+
+#if defined(CONFIG_SMP) && IS_ENABLED(CONFIG_HYPERV)
+static void __init hv_smp_prepare_boot_cpu(void)
+{
+	native_smp_prepare_boot_cpu();
+#if defined(CONFIG_X86_64) && defined(CONFIG_PARAVIRT_SPINLOCKS)
+	hv_init_spinlocks();
+#endif
+}
+
+static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
+{
+#ifdef CONFIG_X86_64
+	int i;
+	int ret;
+#endif
+
+	native_smp_prepare_cpus(max_cpus);
+
+#ifdef CONFIG_X86_64
+	for_each_present_cpu(i) {
+		if (i == 0)
+			continue;
+		ret = hv_call_add_logical_proc(numa_cpu_node(i), i, cpu_physical_id(i));
+		BUG_ON(ret);
+	}
+
+	for_each_present_cpu(i) {
+		if (i == 0)
+			continue;
+		ret = hv_call_create_vp(numa_cpu_node(i), hv_current_partition_id, i, i);
+		BUG_ON(ret);
+	}
+#endif
+}
+#endif
+
+static void __init ms_hyperv_init_platform(void)
+{
+	int hv_max_functions_eax;
+	int hv_host_info_eax;
+	int hv_host_info_ebx;
+	int hv_host_info_ecx;
+	int hv_host_info_edx;
+
+#ifdef CONFIG_PARAVIRT
+	pv_info.name = "Hyper-V";
+#endif
+
+	/*
+	 * Extract the features and hints
+	 */
+	ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES);
+	ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES);
+	ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
+	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
+
+	hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
+
+	pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n",
+		ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints,
+		ms_hyperv.misc_features);
+
+	ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS);
+	ms_hyperv.max_lp_index = cpuid_ebx(HYPERV_CPUID_IMPLEMENT_LIMITS);
+
+	pr_debug("Hyper-V: max %u virtual processors, %u logical processors\n",
+		 ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
+
+	/*
+	 * Check CPU management privilege.
+	 *
+	 * To mirror what Windows does we should extract CPU management
+	 * features and use the ReservedIdentityBit to detect if Linux is the
+	 * root partition. But that requires negotiating CPU management
+	 * interface (a process to be finalized). For now, use the privilege
+	 * flag as the indicator for running as root.
+	 *
+	 * Hyper-V should never specify running as root and as a Confidential
+	 * VM. But to protect against a compromised/malicious Hyper-V trying
+	 * to exploit root behavior to expose Confidential VM memory, ignore
+	 * the root partition setting if also a Confidential VM.
+	 */
+	if ((ms_hyperv.priv_high & HV_CPU_MANAGEMENT) &&
+	    !(ms_hyperv.priv_high & HV_ISOLATION)) {
+		hv_root_partition = true;
+		pr_info("Hyper-V: running as root partition\n");
+	}
+
+	/*
+	 * Extract host information.
+	 */
+	if (hv_max_functions_eax >= HYPERV_CPUID_VERSION) {
+		hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
+		hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
+		hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
+		hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION);
+
+		pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
+			hv_host_info_ebx >> 16, hv_host_info_ebx & 0xFFFF,
+			hv_host_info_eax, hv_host_info_edx & 0xFFFFFF,
+			hv_host_info_ecx, hv_host_info_edx >> 24);
+	}
+
+	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
+	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
+		x86_platform.calibrate_tsc = hv_get_tsc_khz;
+		x86_platform.calibrate_cpu = hv_get_tsc_khz;
+	}
+
+	if (ms_hyperv.priv_high & HV_ISOLATION) {
+		ms_hyperv.isolation_config_a = cpuid_eax(HYPERV_CPUID_ISOLATION_CONFIG);
+		ms_hyperv.isolation_config_b = cpuid_ebx(HYPERV_CPUID_ISOLATION_CONFIG);
+		ms_hyperv.shared_gpa_boundary =
+			BIT_ULL(ms_hyperv.shared_gpa_boundary_bits);
+
+		pr_info("Hyper-V: Isolation Config: Group A 0x%x, Group B 0x%x\n",
+			ms_hyperv.isolation_config_a, ms_hyperv.isolation_config_b);
+
+		if (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP) {
+			static_branch_enable(&isolation_type_snp);
+#ifdef CONFIG_SWIOTLB
+			swiotlb_unencrypted_base = ms_hyperv.shared_gpa_boundary;
+#endif
+		}
+		/* Isolation VMs are unenlightened SEV-based VMs, thus this check: */
+		if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
+			if (hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE)
+				cc_set_vendor(CC_VENDOR_HYPERV);
+		}
+	}
+
+	if (hv_max_functions_eax >= HYPERV_CPUID_NESTED_FEATURES) {
+		ms_hyperv.nested_features =
+			cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
+		pr_info("Hyper-V: Nested features: 0x%x\n",
+			ms_hyperv.nested_features);
+	}
+
+#ifdef CONFIG_X86_LOCAL_APIC
+	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
+	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
+		/*
+		 * Get the APIC frequency.
+		 */
+		u64	hv_lapic_frequency;
+
+		rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
+		hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
+		lapic_timer_period = hv_lapic_frequency;
+		pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
+			lapic_timer_period);
+	}
+
+	register_nmi_handler(NMI_UNKNOWN, hv_nmi_unknown, NMI_FLAG_FIRST,
+			     "hv_nmi_unknown");
+#endif
+
+#ifdef CONFIG_X86_IO_APIC
+	no_timer_check = 1;
+#endif
+
+#if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
+	machine_ops.shutdown = hv_machine_shutdown;
+	machine_ops.crash_shutdown = hv_machine_crash_shutdown;
+#endif
+	if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) {
+		/*
+		 * Writing to synthetic MSR 0x40000118 updates/changes the
+		 * guest visible CPUIDs. Setting bit 0 of this MSR  enables
+		 * guests to report invariant TSC feature through CPUID
+		 * instruction, CPUID 0x800000007/EDX, bit 8. See code in
+		 * early_init_intel() where this bit is examined. The
+		 * setting of this MSR bit should happen before init_intel()
+		 * is called.
+		 */
+		wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1);
+		setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
+	}
+
+	/*
+	 * Generation 2 instances don't support reading the NMI status from
+	 * 0x61 port.
+	 */
+	if (efi_enabled(EFI_BOOT))
+		x86_platform.get_nmi_reason = hv_get_nmi_reason;
+
+	/*
+	 * Hyper-V VMs have a PIT emulation quirk such that zeroing the
+	 * counter register during PIT shutdown restarts the PIT. So it
+	 * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
+	 * to false tells pit_shutdown() not to zero the counter so that
+	 * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
+	 * and setting this value has no effect.
+	 */
+	i8253_clear_counter_on_shutdown = false;
+
+#if IS_ENABLED(CONFIG_HYPERV)
+	/*
+	 * Setup the hook to get control post apic initialization.
+	 */
+	x86_platform.apic_post_init = hyperv_init;
+	hyperv_setup_mmu_ops();
+	/* Setup the IDT for hypervisor callback */
+	alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_hyperv_callback);
+
+	/* Setup the IDT for reenlightenment notifications */
+	if (ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT) {
+		alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
+				asm_sysvec_hyperv_reenlightenment);
+	}
+
+	/* Setup the IDT for stimer0 */
+	if (ms_hyperv.misc_features & HV_STIMER_DIRECT_MODE_AVAILABLE) {
+		alloc_intr_gate(HYPERV_STIMER0_VECTOR,
+				asm_sysvec_hyperv_stimer0);
+	}
+
+# ifdef CONFIG_SMP
+	smp_ops.smp_prepare_boot_cpu = hv_smp_prepare_boot_cpu;
+	if (hv_root_partition)
+		smp_ops.smp_prepare_cpus = hv_smp_prepare_cpus;
+# endif
+
+	/*
+	 * Hyper-V doesn't provide irq remapping for IO-APIC. To enable x2apic,
+	 * set x2apic destination mode to physical mode when x2apic is available
+	 * and Hyper-V IOMMU driver makes sure cpus assigned with IO-APIC irqs
+	 * have 8-bit APIC id.
+	 */
+# ifdef CONFIG_X86_X2APIC
+	if (x2apic_supported())
+		x2apic_phys = 1;
+# endif
+
+	/* Register Hyper-V specific clocksource */
+	hv_init_clocksource();
+#endif
+	/*
+	 * TSC should be marked as unstable only after Hyper-V
+	 * clocksource has been initialized. This ensures that the
+	 * stability of the sched_clock is not altered.
+	 */
+	if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
+		mark_tsc_unstable("running on Hyper-V");
+
+	hardlockup_detector_disable();
+}
+
+static bool __init ms_hyperv_x2apic_available(void)
+{
+	return x2apic_supported();
+}
+
+/*
+ * If ms_hyperv_msi_ext_dest_id() returns true, hyperv_prepare_irq_remapping()
+ * returns -ENODEV and the Hyper-V IOMMU driver is not used; instead, the
+ * generic support of the 15-bit APIC ID is used: see __irq_msi_compose_msg().
+ *
+ * Note: for a VM on Hyper-V, the I/O-APIC is the only device which
+ * (logically) generates MSIs directly to the system APIC irq domain.
+ * There is no HPET, and PCI MSI/MSI-X interrupts are remapped by the
+ * pci-hyperv host bridge.
+ */
+static bool __init ms_hyperv_msi_ext_dest_id(void)
+{
+	u32 eax;
+
+	eax = cpuid_eax(HYPERV_CPUID_VIRT_STACK_INTERFACE);
+	if (eax != HYPERV_VS_INTERFACE_EAX_SIGNATURE)
+		return false;
+
+	eax = cpuid_eax(HYPERV_CPUID_VIRT_STACK_PROPERTIES);
+	return eax & HYPERV_VS_PROPERTIES_EAX_EXTENDED_IOAPIC_RTE;
+}
+
+const __initconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
+	.name			= "Microsoft Hyper-V",
+	.detect			= ms_hyperv_platform,
+	.type			= X86_HYPER_MS_HYPERV,
+	.init.x2apic_available	= ms_hyperv_x2apic_available,
+	.init.msi_ext_dest_id	= ms_hyperv_msi_ext_dest_id,
+	.init.init_platform	= ms_hyperv_init_platform,
+};