arch/arm64/kvm/reset.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012,2013 - ARM Ltd
  * Author: Marc Zyngier <marc.zyngier@arm.com>
  *
  * Derived from arch/arm/kvm/reset.c
  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
  */

 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/kvm_host.h>
 #include <linux/kvm.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/types.h>

 #include <kvm/arm_arch_timer.h>

 #include <asm/cpufeature.h>
 #include <asm/cputype.h>
 #include <asm/fpsimd.h>
 #include <asm/ptrace.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_mmu.h>
 #include <asm/virt.h>

 /* Maximum phys_shift supported for any VM on this host */
 static u32 kvm_ipa_limit;

 /*
  * ARMv8 Reset Values
  */
 #define VCPU_RESET_PSTATE_EL1	(PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT | \
 				 PSR_F_BIT | PSR_D_BIT)

 #define VCPU_RESET_PSTATE_SVC	(PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \
 				 PSR_AA32_I_BIT | PSR_AA32_F_BIT)

 unsigned int kvm_sve_max_vl;

 int kvm_arm_init_sve(void)
 {
 	if (system_supports_sve()) {
 		kvm_sve_max_vl = sve_max_virtualisable_vl();

 		/*
 		 * The get_sve_reg()/set_sve_reg() ioctl interface will need
 		 * to be extended with multiple register slice support in
 		 * order to support vector lengths greater than
 		 * SVE_VL_ARCH_MAX:
 		 */
 		if (WARN_ON(kvm_sve_max_vl > SVE_VL_ARCH_MAX))
 			kvm_sve_max_vl = SVE_VL_ARCH_MAX;

 		/*
 		 * Don't even try to make use of vector lengths that
 		 * aren't available on all CPUs, for now:
 		 */
 		if (kvm_sve_max_vl < sve_max_vl())
 			pr_warn("KVM: SVE vector length for guests limited to %u bytes\n",
 				kvm_sve_max_vl);
 	}

 	return 0;
 }

 static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)
 {
 	if (!system_supports_sve())
 		return -EINVAL;

 	vcpu->arch.sve_max_vl = kvm_sve_max_vl;

 	/*
 	 * Userspace can still customize the vector lengths by writing
 	 * KVM_REG_ARM64_SVE_VLS.  Allocation is deferred until
 	 * kvm_arm_vcpu_finalize(), which freezes the configuration.
 	 */
 	vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SVE;

 	return 0;
 }

 /*
  * Finalize vcpu's maximum SVE vector length, allocating
  * vcpu->arch.sve_state as necessary.
  */
 static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
 {
 	void *buf;
 	unsigned int vl;

 	vl = vcpu->arch.sve_max_vl;

 	/*
 	 * Responsibility for these properties is shared between
 	 * kvm_arm_init_arch_resources(), kvm_vcpu_enable_sve() and
 	 * set_sve_vls().  Double-check here just to be sure:
 	 */
 	if (WARN_ON(!sve_vl_valid(vl) || vl > sve_max_virtualisable_vl() ||
 		    vl > SVE_VL_ARCH_MAX))
 		return -EIO;

 	buf = kzalloc(SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl)), GFP_KERNEL_ACCOUNT);
 	if (!buf)
 		return -ENOMEM;

 	vcpu->arch.sve_state = buf;
 	vcpu->arch.flags |= KVM_ARM64_VCPU_SVE_FINALIZED;
 	return 0;
 }

 int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature)
 {
 	switch (feature) {
 	case KVM_ARM_VCPU_SVE:
 		if (!vcpu_has_sve(vcpu))
 			return -EINVAL;

 		if (kvm_arm_vcpu_sve_finalized(vcpu))
 			return -EPERM;

 		return kvm_vcpu_finalize_sve(vcpu);
 	}

 	return -EINVAL;
 }

 bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu)
 {
 	if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu))
 		return false;

 	return true;
 }

 void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
 	kfree(vcpu->arch.sve_state);
 }

 static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)
 {
 	if (vcpu_has_sve(vcpu))
 		memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu));
 }

 static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
 {
 	/*
 	 * For now make sure that both address/generic pointer authentication
 	 * features are requested by the userspace together and the system
 	 * supports these capabilities.
 	 */
 	if (!test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) ||
 	    !test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features) ||
 	    !system_has_full_ptr_auth())
 		return -EINVAL;

 	vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_PTRAUTH;
 	return 0;
 }

 static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu)
 {
 	struct kvm_vcpu *tmp;
 	bool is32bit;
 	int i;

 	is32bit = vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT);
 	if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit)
 		return false;

 	/* MTE is incompatible with AArch32 */
 	if (kvm_has_mte(vcpu->kvm) && is32bit)
 		return false;

 	/* Check that the vcpus are either all 32bit or all 64bit */
 	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
 		if (vcpu_has_feature(tmp, KVM_ARM_VCPU_EL1_32BIT) != is32bit)
 			return false;
 	}

 	return true;
 }

 /**
  * kvm_reset_vcpu - sets core registers and sys_regs to reset value
  * @vcpu: The VCPU pointer
  *
  * This function finds the right table above and sets the registers on
  * the virtual CPU struct to their architecturally defined reset
  * values, except for registers whose reset is deferred until
  * kvm_arm_vcpu_finalize().
  *
  * Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT
  * ioctl or as part of handling a request issued by another VCPU in the PSCI
  * handling code.  In the first case, the VCPU will not be loaded, and in the
  * second case the VCPU will be loaded.  Because this function operates purely
  * on the memory-backed values of system registers, we want to do a full put if
  * we were loaded (handling a request) and load the values back at the end of
  * the function.  Otherwise we leave the state alone.  In both cases, we
  * disable preemption around the vcpu reset as we would otherwise race with
  * preempt notifiers which also call put/load.
  */
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 {
 	struct vcpu_reset_state reset_state;
 	int ret;
 	bool loaded;
 	u32 pstate;

 	mutex_lock(&vcpu->kvm->lock);
 	reset_state = vcpu->arch.reset_state;
 	WRITE_ONCE(vcpu->arch.reset_state.reset, false);
 	mutex_unlock(&vcpu->kvm->lock);

 	/* Reset PMU outside of the non-preemptible section */
 	kvm_pmu_vcpu_reset(vcpu);

 	preempt_disable();
 	loaded = (vcpu->cpu != -1);
 	if (loaded)
 		kvm_arch_vcpu_put(vcpu);

 	if (!kvm_arm_vcpu_sve_finalized(vcpu)) {
 		if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) {
 			ret = kvm_vcpu_enable_sve(vcpu);
 			if (ret)
 				goto out;
 		}
 	} else {
 		kvm_vcpu_reset_sve(vcpu);
 	}

 	if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) ||
 	    test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) {
 		if (kvm_vcpu_enable_ptrauth(vcpu)) {
 			ret = -EINVAL;
 			goto out;
 		}
 	}

 	if (!vcpu_allowed_register_width(vcpu)) {
 		ret = -EINVAL;
 		goto out;
 	}

 	switch (vcpu->arch.target) {
 	default:
 		if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
 			pstate = VCPU_RESET_PSTATE_SVC;
 		} else {
 			pstate = VCPU_RESET_PSTATE_EL1;
 		}

 		if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
 			ret = -EINVAL;
 			goto out;
 		}
 		break;
 	}

 	/* Reset core registers */
 	memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
 	memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
 	vcpu->arch.ctxt.spsr_abt = 0;
 	vcpu->arch.ctxt.spsr_und = 0;
 	vcpu->arch.ctxt.spsr_irq = 0;
 	vcpu->arch.ctxt.spsr_fiq = 0;
 	vcpu_gp_regs(vcpu)->pstate = pstate;

 	/* Reset system registers */
 	kvm_reset_sys_regs(vcpu);

 	/*
 	 * Additional reset state handling that PSCI may have imposed on us.
 	 * Must be done after all the sys_reg reset.
 	 */
 	if (reset_state.reset) {
 		unsigned long target_pc = reset_state.pc;

 		/* Gracefully handle Thumb2 entry point */
 		if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
 			target_pc &= ~1UL;
 			vcpu_set_thumb(vcpu);
 		}

 		/* Propagate caller endianness */
 		if (reset_state.be)
 			kvm_vcpu_set_be(vcpu);

 		*vcpu_pc(vcpu) = target_pc;
 		vcpu_set_reg(vcpu, 0, reset_state.r0);
 	}

 	/* Reset timer */
 	ret = kvm_timer_vcpu_reset(vcpu);
 out:
 	if (loaded)
 		kvm_arch_vcpu_load(vcpu, smp_processor_id());
 	preempt_enable();
 	return ret;
 }

 u32 get_kvm_ipa_limit(void)
 {
 	return kvm_ipa_limit;
 }

 int kvm_set_ipa_limit(void)
 {
 	unsigned int parange;
 	u64 mmfr0;

 	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
 	parange = cpuid_feature_extract_unsigned_field(mmfr0,
 				ID_AA64MMFR0_PARANGE_SHIFT);
 	/*
 	 * IPA size beyond 48 bits could not be supported
 	 * on either 4K or 16K page size. Hence let's cap
 	 * it to 48 bits, in case it's reported as larger
 	 * on the system.
 	 */
 	if (PAGE_SIZE != SZ_64K)
 		parange = min(parange, (unsigned int)ID_AA64MMFR0_PARANGE_48);

 	/*
 	 * Check with ARMv8.5-GTG that our PAGE_SIZE is supported at
 	 * Stage-2. If not, things will stop very quickly.
 	 */
 	switch (cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_TGRAN_2_SHIFT)) {
 	case ID_AA64MMFR0_TGRAN_2_SUPPORTED_NONE:
 		kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n");
 		return -EINVAL;
 	case ID_AA64MMFR0_TGRAN_2_SUPPORTED_DEFAULT:
 		kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n");
 		break;
 	case ID_AA64MMFR0_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_TGRAN_2_SUPPORTED_MAX:
 		kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n");
 		break;
 	default:
 		kvm_err("Unsupported value for TGRAN_2, giving up\n");
 		return -EINVAL;
 	}

 	kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange);
 	kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit,
 		 ((kvm_ipa_limit < KVM_PHYS_SHIFT) ?
 		  " (Reduced IPA size, limited VM/VMM compatibility)" : ""));

 	return 0;
 }

 int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
 {
 	u64 mmfr0, mmfr1;
 	u32 phys_shift;

 	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
 		return -EINVAL;

 	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
 	if (phys_shift) {
 		if (phys_shift > kvm_ipa_limit ||
 		    phys_shift < ARM64_MIN_PARANGE_BITS)
 			return -EINVAL;
 	} else {
 		phys_shift = KVM_PHYS_SHIFT;
 		if (phys_shift > kvm_ipa_limit) {
 			pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n",
 				     current->comm);
 			return -EINVAL;
 		}
 	}

 	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
 	mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
 	kvm->arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2012,2013 - ARM Ltd
	* Author: Marc Zyngier <marc.zyngier@arm.com>
	*
	* Derived from arch/arm/kvm/reset.c
	* Copyright (C) 2012 - Virtual Open Systems and Columbia University
	* Author: Christoffer Dall <c.dall@virtualopensystems.com>
	*/

	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/kvm_host.h>
	#include <linux/kvm.h>
	#include <linux/hw_breakpoint.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <linux/types.h>

	#include <kvm/arm_arch_timer.h>

	#include <asm/cpufeature.h>
	#include <asm/cputype.h>
	#include <asm/fpsimd.h>
	#include <asm/ptrace.h>
	#include <asm/kvm_arm.h>
	#include <asm/kvm_asm.h>
	#include <asm/kvm_emulate.h>
	#include <asm/kvm_mmu.h>
	#include <asm/virt.h>

	/* Maximum phys_shift supported for any VM on this host */
	static u32 kvm_ipa_limit;

	/*
	* ARMv8 Reset Values
	*/
	#define VCPU_RESET_PSTATE_EL1 (PSR_MODE_EL1h \| PSR_A_BIT \| PSR_I_BIT \| \
	PSR_F_BIT \| PSR_D_BIT)

	#define VCPU_RESET_PSTATE_SVC (PSR_AA32_MODE_SVC \| PSR_AA32_A_BIT \| \
	PSR_AA32_I_BIT \| PSR_AA32_F_BIT)

	unsigned int kvm_sve_max_vl;

	int kvm_arm_init_sve(void)
	{
	if (system_supports_sve()) {
	kvm_sve_max_vl = sve_max_virtualisable_vl();

	/*
	* The get_sve_reg()/set_sve_reg() ioctl interface will need
	* to be extended with multiple register slice support in
	* order to support vector lengths greater than
	* SVE_VL_ARCH_MAX:
	*/
	if (WARN_ON(kvm_sve_max_vl > SVE_VL_ARCH_MAX))
	kvm_sve_max_vl = SVE_VL_ARCH_MAX;

	/*
	* Don't even try to make use of vector lengths that
	* aren't available on all CPUs, for now:
	*/
	if (kvm_sve_max_vl < sve_max_vl())
	pr_warn("KVM: SVE vector length for guests limited to %u bytes\n",
	kvm_sve_max_vl);
	}

	return 0;
	}

	static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)
	{
	if (!system_supports_sve())
	return -EINVAL;

	vcpu->arch.sve_max_vl = kvm_sve_max_vl;

	/*
	* Userspace can still customize the vector lengths by writing
	* KVM_REG_ARM64_SVE_VLS. Allocation is deferred until
	* kvm_arm_vcpu_finalize(), which freezes the configuration.
	*/
	vcpu->arch.flags \|= KVM_ARM64_GUEST_HAS_SVE;

	return 0;
	}

	/*
	* Finalize vcpu's maximum SVE vector length, allocating
	* vcpu->arch.sve_state as necessary.
	*/
	static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
	{
	void *buf;
	unsigned int vl;

	vl = vcpu->arch.sve_max_vl;

	/*
	* Responsibility for these properties is shared between
	* kvm_arm_init_arch_resources(), kvm_vcpu_enable_sve() and
	* set_sve_vls(). Double-check here just to be sure:
	*/
	if (WARN_ON(!sve_vl_valid(vl) \|\| vl > sve_max_virtualisable_vl() \|\|
	vl > SVE_VL_ARCH_MAX))
	return -EIO;

	buf = kzalloc(SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl)), GFP_KERNEL_ACCOUNT);
	if (!buf)
	return -ENOMEM;

	vcpu->arch.sve_state = buf;
	vcpu->arch.flags \|= KVM_ARM64_VCPU_SVE_FINALIZED;
	return 0;
	}

	int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature)
	{
	switch (feature) {
	case KVM_ARM_VCPU_SVE:
	if (!vcpu_has_sve(vcpu))
	return -EINVAL;

	if (kvm_arm_vcpu_sve_finalized(vcpu))
	return -EPERM;

	return kvm_vcpu_finalize_sve(vcpu);
	}

	return -EINVAL;
	}

	bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu)
	{
	if (vcpu_has_sve(vcpu) && !kvm_arm_vcpu_sve_finalized(vcpu))
	return false;

	return true;
	}

	void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
	{
	kfree(vcpu->arch.sve_state);
	}

	static void kvm_vcpu_reset_sve(struct kvm_vcpu *vcpu)
	{
	if (vcpu_has_sve(vcpu))
	memset(vcpu->arch.sve_state, 0, vcpu_sve_state_size(vcpu));
	}

	static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
	{
	/*
	* For now make sure that both address/generic pointer authentication
	* features are requested by the userspace together and the system
	* supports these capabilities.
	*/
	if (!test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) \|\|
	!test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features) \|\|
	!system_has_full_ptr_auth())
	return -EINVAL;

	vcpu->arch.flags \|= KVM_ARM64_GUEST_HAS_PTRAUTH;
	return 0;
	}

	static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu)
	{
	struct kvm_vcpu *tmp;
	bool is32bit;
	int i;

	is32bit = vcpu_has_feature(vcpu, KVM_ARM_VCPU_EL1_32BIT);
	if (!cpus_have_const_cap(ARM64_HAS_32BIT_EL1) && is32bit)
	return false;

	/* MTE is incompatible with AArch32 */
	if (kvm_has_mte(vcpu->kvm) && is32bit)
	return false;

	/* Check that the vcpus are either all 32bit or all 64bit */
	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
	if (vcpu_has_feature(tmp, KVM_ARM_VCPU_EL1_32BIT) != is32bit)
	return false;
	}

	return true;
	}

	/**
	* kvm_reset_vcpu - sets core registers and sys_regs to reset value
	* @vcpu: The VCPU pointer
	*
	* This function finds the right table above and sets the registers on
	* the virtual CPU struct to their architecturally defined reset
	* values, except for registers whose reset is deferred until
	* kvm_arm_vcpu_finalize().
	*
	* Note: This function can be called from two paths: The KVM_ARM_VCPU_INIT
	* ioctl or as part of handling a request issued by another VCPU in the PSCI
	* handling code. In the first case, the VCPU will not be loaded, and in the
	* second case the VCPU will be loaded. Because this function operates purely
	* on the memory-backed values of system registers, we want to do a full put if
	* we were loaded (handling a request) and load the values back at the end of
	* the function. Otherwise we leave the state alone. In both cases, we
	* disable preemption around the vcpu reset as we would otherwise race with
	* preempt notifiers which also call put/load.
	*/
	int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
	{
	struct vcpu_reset_state reset_state;
	int ret;
	bool loaded;
	u32 pstate;

	mutex_lock(&vcpu->kvm->lock);
	reset_state = vcpu->arch.reset_state;
	WRITE_ONCE(vcpu->arch.reset_state.reset, false);
	mutex_unlock(&vcpu->kvm->lock);

	/* Reset PMU outside of the non-preemptible section */
	kvm_pmu_vcpu_reset(vcpu);

	preempt_disable();
	loaded = (vcpu->cpu != -1);
	if (loaded)
	kvm_arch_vcpu_put(vcpu);

	if (!kvm_arm_vcpu_sve_finalized(vcpu)) {
	if (test_bit(KVM_ARM_VCPU_SVE, vcpu->arch.features)) {
	ret = kvm_vcpu_enable_sve(vcpu);
	if (ret)
	goto out;
	}
	} else {
	kvm_vcpu_reset_sve(vcpu);
	}

	if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, vcpu->arch.features) \|\|
	test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, vcpu->arch.features)) {
	if (kvm_vcpu_enable_ptrauth(vcpu)) {
	ret = -EINVAL;
	goto out;
	}
	}

	if (!vcpu_allowed_register_width(vcpu)) {
	ret = -EINVAL;
	goto out;
	}

	switch (vcpu->arch.target) {
	default:
	if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
	pstate = VCPU_RESET_PSTATE_SVC;
	} else {
	pstate = VCPU_RESET_PSTATE_EL1;
	}

	if (kvm_vcpu_has_pmu(vcpu) && !kvm_arm_support_pmu_v3()) {
	ret = -EINVAL;
	goto out;
	}
	break;
	}

	/* Reset core registers */
	memset(vcpu_gp_regs(vcpu), 0, sizeof(*vcpu_gp_regs(vcpu)));
	memset(&vcpu->arch.ctxt.fp_regs, 0, sizeof(vcpu->arch.ctxt.fp_regs));
	vcpu->arch.ctxt.spsr_abt = 0;
	vcpu->arch.ctxt.spsr_und = 0;
	vcpu->arch.ctxt.spsr_irq = 0;
	vcpu->arch.ctxt.spsr_fiq = 0;
	vcpu_gp_regs(vcpu)->pstate = pstate;

	/* Reset system registers */
	kvm_reset_sys_regs(vcpu);

	/*
	* Additional reset state handling that PSCI may have imposed on us.
	* Must be done after all the sys_reg reset.
	*/
	if (reset_state.reset) {
	unsigned long target_pc = reset_state.pc;

	/* Gracefully handle Thumb2 entry point */
	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
	target_pc &= ~1UL;
	vcpu_set_thumb(vcpu);
	}

	/* Propagate caller endianness */
	if (reset_state.be)
	kvm_vcpu_set_be(vcpu);

	*vcpu_pc(vcpu) = target_pc;
	vcpu_set_reg(vcpu, 0, reset_state.r0);
	}

	/* Reset timer */
	ret = kvm_timer_vcpu_reset(vcpu);
	out:
	if (loaded)
	kvm_arch_vcpu_load(vcpu, smp_processor_id());
	preempt_enable();
	return ret;
	}

	u32 get_kvm_ipa_limit(void)
	{
	return kvm_ipa_limit;
	}

	int kvm_set_ipa_limit(void)
	{
	unsigned int parange;
	u64 mmfr0;

	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
	parange = cpuid_feature_extract_unsigned_field(mmfr0,
	ID_AA64MMFR0_PARANGE_SHIFT);
	/*
	* IPA size beyond 48 bits could not be supported
	* on either 4K or 16K page size. Hence let's cap
	* it to 48 bits, in case it's reported as larger
	* on the system.
	*/
	if (PAGE_SIZE != SZ_64K)
	parange = min(parange, (unsigned int)ID_AA64MMFR0_PARANGE_48);

	/*
	* Check with ARMv8.5-GTG that our PAGE_SIZE is supported at
	* Stage-2. If not, things will stop very quickly.
	*/
	switch (cpuid_feature_extract_unsigned_field(mmfr0, ID_AA64MMFR0_TGRAN_2_SHIFT)) {
	case ID_AA64MMFR0_TGRAN_2_SUPPORTED_NONE:
	kvm_err("PAGE_SIZE not supported at Stage-2, giving up\n");
	return -EINVAL;
	case ID_AA64MMFR0_TGRAN_2_SUPPORTED_DEFAULT:
	kvm_debug("PAGE_SIZE supported at Stage-2 (default)\n");
	break;
	case ID_AA64MMFR0_TGRAN_2_SUPPORTED_MIN ... ID_AA64MMFR0_TGRAN_2_SUPPORTED_MAX:
	kvm_debug("PAGE_SIZE supported at Stage-2 (advertised)\n");
	break;
	default:
	kvm_err("Unsupported value for TGRAN_2, giving up\n");
	return -EINVAL;
	}

	kvm_ipa_limit = id_aa64mmfr0_parange_to_phys_shift(parange);
	kvm_info("IPA Size Limit: %d bits%s\n", kvm_ipa_limit,
	((kvm_ipa_limit < KVM_PHYS_SHIFT) ?
	" (Reduced IPA size, limited VM/VMM compatibility)" : ""));

	return 0;
	}

	int kvm_arm_setup_stage2(struct kvm *kvm, unsigned long type)
	{
	u64 mmfr0, mmfr1;
	u32 phys_shift;

	if (type & ~KVM_VM_TYPE_ARM_IPA_SIZE_MASK)
	return -EINVAL;

	phys_shift = KVM_VM_TYPE_ARM_IPA_SIZE(type);
	if (phys_shift) {
	if (phys_shift > kvm_ipa_limit \|\|
	phys_shift < ARM64_MIN_PARANGE_BITS)
	return -EINVAL;
	} else {
	phys_shift = KVM_PHYS_SHIFT;
	if (phys_shift > kvm_ipa_limit) {
	pr_warn_once("%s using unsupported default IPA limit, upgrade your VMM\n",
	current->comm);
	return -EINVAL;
	}
	}

	mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
	mmfr1 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
	kvm->arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);

	return 0;
	}