diff --git a/MAINTAINERS b/MAINTAINERS
index 546aa66..0a22f3a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8235,6 +8235,9 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git
 F:	Documentation/ABI/stable/sysfs-bus-vmbus
 F:	Documentation/ABI/testing/debugfs-hyperv
 F:	Documentation/networking/device_drivers/ethernet/microsoft/netvsc.rst
+F:	arch/arm64/hyperv
+F:	arch/arm64/include/asm/hyperv-tlfs.h
+F:	arch/arm64/include/asm/mshyperv.h
 F:	arch/x86/hyperv
 F:	arch/x86/include/asm/hyperv-tlfs.h
 F:	arch/x86/include/asm/mshyperv.h
diff --git a/arch/arm64/Kbuild b/arch/arm64/Kbuild
index d646582..7a37608 100644
--- a/arch/arm64/Kbuild
+++ b/arch/arm64/Kbuild
@@ -3,4 +3,5 @@ obj-y			+= kernel/ mm/
 obj-$(CONFIG_NET)	+= net/
 obj-$(CONFIG_KVM)	+= kvm/
 obj-$(CONFIG_XEN)	+= xen/
+obj-$(subst m,y,$(CONFIG_HYPERV))	+= hyperv/
 obj-$(CONFIG_CRYPTO)	+= crypto/
diff --git a/arch/arm64/hyperv/Makefile b/arch/arm64/hyperv/Makefile
new file mode 100644
index 0000000..1697d30
--- /dev/null
+++ b/arch/arm64/hyperv/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-y		:= hv_core.o
diff --git a/arch/arm64/hyperv/hv_core.c b/arch/arm64/hyperv/hv_core.c
new file mode 100644
index 0000000..9a37124
--- /dev/null
+++ b/arch/arm64/hyperv/hv_core.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Low level utility routines for interacting with Hyper-V.
+ *
+ * Copyright (C) 2021, Microsoft, Inc.
+ *
+ * Author : Michael Kelley <mikelley@microsoft.com>
+ */
+
+
+#include <linux/types.h>
+#include <linux/log2.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/hyperv.h>
+#include <linux/arm-smccc.h>
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <asm-generic/bug.h>
+#include <asm/hyperv-tlfs.h>
+#include <asm/mshyperv.h>
+
+/*
+ * hv_do_hypercall- Invoke the specified hypercall
+ */
+u64 hv_do_hypercall(u64 control, void *input, void *output)
+{
+	u64 input_address;
+	u64 output_address;
+	struct arm_smccc_res res;
+
+	input_address = input ? virt_to_phys(input) : 0;
+	output_address = output ? virt_to_phys(output) : 0;
+
+	arm_smccc_1_1_hvc(HV_FUNC_ID, control,
+			  input_address, output_address, &res);
+	return res.a0;
+}
+EXPORT_SYMBOL_GPL(hv_do_hypercall);
+
+/*
+ * hv_do_fast_hypercall8 -- Invoke the specified hypercall
+ * with arguments in registers instead of physical memory.
+ * Avoids the overhead of virt_to_phys for simple hypercalls.
+ */
+
+u64 hv_do_fast_hypercall8(u16 code, u64 input)
+{
+	u64 control;
+	struct arm_smccc_res res;
+
+	control = (u64)code | HV_HYPERCALL_FAST_BIT;
+
+	arm_smccc_1_1_hvc(HV_FUNC_ID, control, input, &res);
+	return res.a0;
+}
+EXPORT_SYMBOL_GPL(hv_do_fast_hypercall8);
+
+
+/*
+ * Set a single VP register to a 64-bit value.
+ */
+void hv_set_vpreg(u32 msr, u64 value)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_hvc(
+		HV_FUNC_ID,
+		HVCALL_SET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT |
+			HV_HYPERCALL_REP_COMP_1,
+		HV_PARTITION_ID_SELF,
+		HV_VP_INDEX_SELF,
+		msr,
+		0,
+		value,
+		0,
+		&res);
+
+	/*
+	 * Something is fundamentally broken in the hypervisor if
+	 * setting a VP register fails. There's really no way to
+	 * continue as a guest VM, so panic.
+	 */
+	BUG_ON((res.a0 & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS);
+}
+EXPORT_SYMBOL_GPL(hv_set_vpreg);
+
+/*
+ * Get the value of a single VP register.  One version
+ * returns just 64 bits and another returns the full 128 bits.
+ * The two versions are separate to avoid complicating the
+ * calling sequence for the more frequently used 64 bit version.
+ */
+
+void __hv_get_vpreg_128(u32 msr,
+			struct hv_get_vp_registers_input  *input,
+			struct hv_get_vp_registers_output *res)
+{
+	u64	status;
+
+	input->header.partitionid = HV_PARTITION_ID_SELF;
+	input->header.vpindex = HV_VP_INDEX_SELF;
+	input->header.inputvtl = 0;
+	input->element[0].name0 = msr;
+	input->element[0].name1 = 0;
+
+
+	status = hv_do_hypercall(
+		HVCALL_GET_VP_REGISTERS | HV_HYPERCALL_REP_COMP_1,
+		input, res);
+
+	/*
+	 * Something is fundamentally broken in the hypervisor if
+	 * getting a VP register fails. There's really no way to
+	 * continue as a guest VM, so panic.
+	 */
+	BUG_ON((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS);
+}
+
+u64 hv_get_vpreg(u32 msr)
+{
+	struct hv_get_vp_registers_input	*input;
+	struct hv_get_vp_registers_output	*output;
+	u64					result;
+
+	/*
+	 * Allocate a power of 2 size so alignment to that size is
+	 * guaranteed, since the hypercall input and output areas
+	 * must not cross a page boundary.
+	 */
+	input = kzalloc(roundup_pow_of_two(sizeof(input->header) +
+				sizeof(input->element[0])), GFP_ATOMIC);
+	output = kmalloc(roundup_pow_of_two(sizeof(*output)), GFP_ATOMIC);
+
+	__hv_get_vpreg_128(msr, input, output);
+
+	result = output->as64.low;
+	kfree(input);
+	kfree(output);
+	return result;
+}
+EXPORT_SYMBOL_GPL(hv_get_vpreg);
+
+void hv_get_vpreg_128(u32 msr, struct hv_get_vp_registers_output *res)
+{
+	struct hv_get_vp_registers_input	*input;
+	struct hv_get_vp_registers_output	*output;
+
+	/*
+	 * Allocate a power of 2 size so alignment to that size is
+	 * guaranteed, since the hypercall input and output areas
+	 * must not cross a page boundary.
+	 */
+	input = kzalloc(roundup_pow_of_two(sizeof(input->header) +
+				sizeof(input->element[0])), GFP_ATOMIC);
+	output = kmalloc(roundup_pow_of_two(sizeof(*output)), GFP_ATOMIC);
+
+	__hv_get_vpreg_128(msr, input, output);
+
+	res->as64.low = output->as64.low;
+	res->as64.high = output->as64.high;
+	kfree(input);
+	kfree(output);
+}
+EXPORT_SYMBOL_GPL(hv_get_vpreg_128);
diff --git a/arch/arm64/include/asm/hyperv-tlfs.h b/arch/arm64/include/asm/hyperv-tlfs.h
new file mode 100644
index 0000000..4d964a7
--- /dev/null
+++ b/arch/arm64/include/asm/hyperv-tlfs.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * This file contains definitions from the Hyper-V Hypervisor Top-Level
+ * Functional Specification (TLFS):
+ * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs
+ *
+ * Copyright (C) 2021, Microsoft, Inc.
+ *
+ * Author : Michael Kelley <mikelley@microsoft.com>
+ */
+
+#ifndef _ASM_HYPERV_TLFS_H
+#define _ASM_HYPERV_TLFS_H
+
+#include <linux/types.h>
+
+/*
+ * All data structures defined in the TLFS that are shared between Hyper-V
+ * and a guest VM use Little Endian byte ordering.  This matches the default
+ * byte ordering of Linux running on ARM64, so no special handling is required.
+ */
+
+/*
+ * These Hyper-V registers provide information equivalent to the CPUID
+ * instruction on x86/x64.
+ */
+#define HV_REGISTER_HYPERVISOR_VERSION		0x00000100 /*CPUID 0x40000002 */
+#define HV_REGISTER_FEATURES			0x00000200 /*CPUID 0x40000003 */
+#define HV_REGISTER_ENLIGHTENMENTS		0x00000201 /*CPUID 0x40000004 */
+
+/*
+ * Group C Features. See the asm-generic version of hyperv-tlfs.h
+ * for a description of Feature Groups.
+ */
+
+/* Crash MSRs available */
+#define HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE	BIT(8)
+
+/* STIMER direct mode is available */
+#define HV_STIMER_DIRECT_MODE_AVAILABLE		BIT(13)
+
+/*
+ * Synthetic register definitions equivalent to MSRs on x86/x64
+ */
+#define HV_REGISTER_CRASH_P0		0x00000210
+#define HV_REGISTER_CRASH_P1		0x00000211
+#define HV_REGISTER_CRASH_P2		0x00000212
+#define HV_REGISTER_CRASH_P3		0x00000213
+#define HV_REGISTER_CRASH_P4		0x00000214
+#define HV_REGISTER_CRASH_CTL		0x00000215
+
+#define HV_REGISTER_GUEST_OSID		0x00090002
+#define HV_REGISTER_VP_INDEX		0x00090003
+#define HV_REGISTER_TIME_REF_COUNT	0x00090004
+#define HV_REGISTER_REFERENCE_TSC	0x00090017
+
+#define HV_REGISTER_SINT0		0x000A0000
+#define HV_REGISTER_SCONTROL		0x000A0010
+#define HV_REGISTER_SIEFP		0x000A0012
+#define HV_REGISTER_SIMP		0x000A0013
+#define HV_REGISTER_EOM			0x000A0014
+
+#define HV_REGISTER_STIMER0_CONFIG	0x000B0000
+#define HV_REGISTER_STIMER0_COUNT	0x000B0001
+
+#include <asm-generic/hyperv-tlfs.h>
+
+#endif
diff --git a/arch/arm64/include/asm/mshyperv.h b/arch/arm64/include/asm/mshyperv.h
new file mode 100644
index 0000000..44ee012
--- /dev/null
+++ b/arch/arm64/include/asm/mshyperv.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Linux-specific definitions for managing interactions with Microsoft's
+ * Hyper-V hypervisor. The definitions in this file are specific to
+ * the ARM64 architecture.  See include/asm-generic/mshyperv.h for
+ * definitions are that architecture independent.
+ *
+ * Definitions that are specified in the Hyper-V Top Level Functional
+ * Spec (TLFS) should not go in this file, but should instead go in
+ * hyperv-tlfs.h.
+ *
+ * Copyright (C) 2021, Microsoft, Inc.
+ *
+ * Author : Michael Kelley <mikelley@microsoft.com>
+ */
+
+#ifndef _ASM_MSHYPERV_H
+#define _ASM_MSHYPERV_H
+
+#include <linux/types.h>
+#include <linux/arm-smccc.h>
+#include <asm/hyperv-tlfs.h>
+
+/*
+ * Declare calls to get and set Hyper-V VP register values on ARM64, which
+ * requires a hypercall.
+ */
+
+extern void hv_set_vpreg(u32 reg, u64 value);
+extern u64 hv_get_vpreg(u32 reg);
+extern void __hv_get_vpreg_128(u32 reg, struct hv_get_vp_registers_input *input,
+					struct hv_get_vp_registers_output *result);
+
+static inline void hv_set_register(unsigned int reg, u64 value)
+{
+	hv_set_vpreg(reg, value);
+}
+
+static inline u64 hv_get_register(unsigned int reg)
+{
+	return hv_get_vpreg(reg);
+}
+
+/* SMCCC hypercall parameters */
+#define HV_SMCCC_FUNC_NUMBER	1
+#define HV_FUNC_ID	ARM_SMCCC_CALL_VAL(			\
+				ARM_SMCCC_STD_CALL,		\
+				ARM_SMCCC_SMC_64,		\
+				ARM_SMCCC_OWNER_VENDOR_HYP,	\
+				HV_SMCCC_FUNC_NUMBER)
+
+#include <asm-generic/mshyperv.h>
+
+#endif
