1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 4 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 5 */
 6#include <linux/compiler.h>
 7#include <linux/errno.h>
 8#include <linux/sched.h>
 9#include <linux/kvm_host.h>
10#include <linux/kvm.h>
11
12#include <asm/unified.h>
13#include <asm/ptrace.h>
14#include <asm/cputype.h>
15#include <asm/kvm_arm.h>
16#include <asm/kvm_coproc.h>
17#include <asm/kvm_emulate.h>
18
19#include <kvm/arm_arch_timer.h>
20
21/******************************************************************************
22 * Cortex-A15 and Cortex-A7 Reset Values
23 */
24
25static struct kvm_regs cortexa_regs_reset = {
26	.usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
27};
28
29
30/*******************************************************************************
31 * Exported reset function
32 */
33
34/**
35 * kvm_reset_vcpu - sets core registers and cp15 registers to reset value
36 * @vcpu: The VCPU pointer
37 *
38 * This function finds the right table above and sets the registers on the
39 * virtual CPU struct to their architecturally defined reset values.
40 */
41int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
42{
43	struct kvm_regs *reset_regs;
44
45	switch (vcpu->arch.target) {
46	case KVM_ARM_TARGET_CORTEX_A7:
47	case KVM_ARM_TARGET_CORTEX_A15:
48		reset_regs = &cortexa_regs_reset;
49		vcpu->arch.midr = read_cpuid_id();
50		break;
51	default:
52		return -ENODEV;
53	}
54
55	/* Reset core registers */
56	memcpy(&vcpu->arch.ctxt.gp_regs, reset_regs, sizeof(vcpu->arch.ctxt.gp_regs));
57
58	/* Reset CP15 registers */
59	kvm_reset_coprocs(vcpu);
60
61	/*
62	 * Additional reset state handling that PSCI may have imposed on us.
63	 * Must be done after all the sys_reg reset.
64	 */
65	if (READ_ONCE(vcpu->arch.reset_state.reset)) {
66		unsigned long target_pc = vcpu->arch.reset_state.pc;
67
68		/* Gracefully handle Thumb2 entry point */
69		if (target_pc & 1) {
70			target_pc &= ~1UL;
71			vcpu_set_thumb(vcpu);
72		}
73
74		/* Propagate caller endianness */
75		if (vcpu->arch.reset_state.be)
76			kvm_vcpu_set_be(vcpu);
77
78		*vcpu_pc(vcpu) = target_pc;
79		vcpu_set_reg(vcpu, 0, vcpu->arch.reset_state.r0);
80
81		vcpu->arch.reset_state.reset = false;
82	}
83
84	/* Reset arch_timer context */
85	return kvm_timer_vcpu_reset(vcpu);
86}