1/*
2 * Copyright (C) 2012,2013 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * Derived from arch/arm/kvm/reset.c
6 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License, version 2, as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/errno.h>
23#include <linux/kvm_host.h>
24#include <linux/kvm.h>
25#include <linux/hw_breakpoint.h>
26
27#include <kvm/arm_arch_timer.h>
28
29#include <asm/cputype.h>
30#include <asm/ptrace.h>
31#include <asm/kvm_arm.h>
32#include <asm/kvm_coproc.h>
33
34/*
35 * ARMv8 Reset Values
36 */
37static const struct kvm_regs default_regs_reset = {
38	.regs.pstate = (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT |
39			PSR_F_BIT | PSR_D_BIT),
40};
41
42static const struct kvm_regs default_regs_reset32 = {
43	.regs.pstate = (COMPAT_PSR_MODE_SVC | COMPAT_PSR_A_BIT |
44			COMPAT_PSR_I_BIT | COMPAT_PSR_F_BIT),
45};
46
47static const struct kvm_irq_level default_vtimer_irq = {
48	.irq	= 27,
49	.level	= 1,
50};
51
52static bool cpu_has_32bit_el1(void)
53{
54	u64 pfr0;
55
56	pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1);
57	return !!(pfr0 & 0x20);
58}
59
60/**
61 * kvm_arch_dev_ioctl_check_extension
62 *
63 * We currently assume that the number of HW registers is uniform
64 * across all CPUs (see cpuinfo_sanity_check).
65 */
66int kvm_arch_dev_ioctl_check_extension(long ext)
67{
68	int r;
69
70	switch (ext) {
71	case KVM_CAP_ARM_EL1_32BIT:
72		r = cpu_has_32bit_el1();
73		break;
74	case KVM_CAP_GUEST_DEBUG_HW_BPS:
75		r = get_num_brps();
76		break;
77	case KVM_CAP_GUEST_DEBUG_HW_WPS:
78		r = get_num_wrps();
79		break;
80	case KVM_CAP_SET_GUEST_DEBUG:
81		r = 1;
82		break;
83	default:
84		r = 0;
85	}
86
87	return r;
88}
89
90/**
91 * kvm_reset_vcpu - sets core registers and sys_regs to reset value
92 * @vcpu: The VCPU pointer
93 *
94 * This function finds the right table above and sets the registers on
95 * the virtual CPU struct to their architectually defined reset
96 * values.
97 */
98int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
99{
100	const struct kvm_irq_level *cpu_vtimer_irq;
101	const struct kvm_regs *cpu_reset;
102
103	switch (vcpu->arch.target) {
104	default:
105		if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
106			if (!cpu_has_32bit_el1())
107				return -EINVAL;
108			cpu_reset = &default_regs_reset32;
109		} else {
110			cpu_reset = &default_regs_reset;
111		}
112
113		cpu_vtimer_irq = &default_vtimer_irq;
114		break;
115	}
116
117	/* Reset core registers */
118	memcpy(vcpu_gp_regs(vcpu), cpu_reset, sizeof(*cpu_reset));
119
120	/* Reset system registers */
121	kvm_reset_sys_regs(vcpu);
122
123	/* Reset timer */
124	return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
125}
126