path: root/arch/arm64/kvm/guest.c

// 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/guest.c:
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#include <linux/bits.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/nospec.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <kvm/arm_hypercalls.h>
#include <asm/cputype.h>
#include <linux/uaccess.h>
#include <asm/fpsimd.h>
#include <asm/kvm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_nested.h>
#include <asm/sigcontext.h>

#include "trace.h"

const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
	KVM_GENERIC_VM_STATS()
};

const struct kvm_stats_header kvm_vm_stats_header = {
	.name_size = KVM_STATS_NAME_SIZE,
	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
	.id_offset =  sizeof(struct kvm_stats_header),
	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
		       sizeof(kvm_vm_stats_desc),
};

const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
	KVM_GENERIC_VCPU_STATS(),
	STATS_DESC_COUNTER(VCPU, hvc_exit_stat),
	STATS_DESC_COUNTER(VCPU, wfe_exit_stat),
	STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
	STATS_DESC_COUNTER(VCPU, mmio_exit_user),
	STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
	STATS_DESC_COUNTER(VCPU, signal_exits),
	STATS_DESC_COUNTER(VCPU, exits)
};

const struct kvm_stats_header kvm_vcpu_stats_header = {
	.name_size = KVM_STATS_NAME_SIZE,
	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
	.id_offset = sizeof(struct kvm_stats_header),
	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
		       sizeof(kvm_vcpu_stats_desc),
};

static bool core_reg_offset_is_vreg(u64 off)
{
	return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) &&
		off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr);
}

static u64 core_reg_offset_from_id(u64 id)
{
	return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
}

static int core_reg_size_from_offset(const struct kvm_vcpu *vcpu, u64 off)
{
	int size;

	switch (off) {
	case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
	     KVM_REG_ARM_CORE_REG(regs.regs[30]):
	case KVM_REG_ARM_CORE_REG(regs.sp):
	case KVM_REG_ARM_CORE_REG(regs.pc):
	case KVM_REG_ARM_CORE_REG(regs.pstate):
	case KVM_REG_ARM_CORE_REG(sp_el1):
	case KVM_REG_ARM_CORE_REG(elr_el1):
	case KVM_REG_ARM_CORE_REG(spsr[0]) ...
	     KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]):
		size = sizeof(__u64);
		break;

	case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
	     KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
		size = sizeof(__uint128_t);
		break;

	case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
	case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
		size = sizeof(__u32);
		break;

	default:
		return -EINVAL;
	}

	if (!IS_ALIGNED(off, size / sizeof(__u32)))
		return -EINVAL;

	/*
	 * The KVM_REG_ARM64_SVE regs must be used instead of
	 * KVM_REG_ARM_CORE for accessing the FPSIMD V-registers on
	 * SVE-enabled vcpus:
	 */
	if (vcpu_has_sve(vcpu) && core_reg_offset_is_vreg(off))
		return -EINVAL;

	return size;
}

static void *core_reg_addr(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
	u64 off = core_reg_offset_from_id(reg->id);
	int size = core_reg_size_from_offset(vcpu, off);

	if (size < 0)
		return NULL;

	if (KVM_REG_SIZE(reg->id) != size)
		return NULL;

	switch (off) {
	case KVM_REG_ARM_CORE_REG(regs.regs[0]) ...
	     KVM_REG_ARM_CORE_REG(regs.regs[30]):
		off -= KVM_REG_ARM_CORE_REG(regs.regs[0]);
		off /= 2;
		return &vcpu->arch.ctxt.regs.regs[off];

	case KVM_REG_ARM_CORE_REG(regs.sp):
		return &vcpu->arch.ctxt.regs.sp;

	case KVM_REG_ARM_CORE_REG(regs.pc):
		return &vcpu->arch.ctxt.regs.pc;

	case KVM_REG_ARM_CORE_REG