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
26 #include <kvm/arm_arch_timer.h>
27
28 #include <asm/cputype.h>
29 #include <asm/ptrace.h>
30 #include <asm/kvm_arm.h>
31 #include <asm/kvm_coproc.h>
32
33 /*
34 * ARMv8 Reset Values
35 */
36 static const struct kvm_regs default_regs_reset = {
37 .regs.pstate = (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT |
38 PSR_F_BIT | PSR_D_BIT),
39 };
40
41 static const struct kvm_regs default_regs_reset32 = {
42 .regs.pstate = (COMPAT_PSR_MODE_SVC | COMPAT_PSR_A_BIT |
43 COMPAT_PSR_I_BIT | COMPAT_PSR_F_BIT),
44 };
45
46 static const struct kvm_irq_level default_vtimer_irq = {
47 .irq = 27,
48 .level = 1,
49 };
50
cpu_has_32bit_el1(void)51 static bool cpu_has_32bit_el1(void)
52 {
53 u64 pfr0;
54
55 pfr0 = read_system_reg(SYS_ID_AA64PFR0_EL1);
56 return !!(pfr0 & 0x20);
57 }
58
kvm_arch_dev_ioctl_check_extension(long ext)59 int kvm_arch_dev_ioctl_check_extension(long ext)
60 {
61 int r;
62
63 switch (ext) {
64 case KVM_CAP_ARM_EL1_32BIT:
65 r = cpu_has_32bit_el1();
66 break;
67 default:
68 r = 0;
69 }
70
71 return r;
72 }
73
74 /**
75 * kvm_reset_vcpu - sets core registers and sys_regs to reset value
76 * @vcpu: The VCPU pointer
77 *
78 * This function finds the right table above and sets the registers on
79 * the virtual CPU struct to their architectually defined reset
80 * values.
81 */
kvm_reset_vcpu(struct kvm_vcpu * vcpu)82 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
83 {
84 const struct kvm_irq_level *cpu_vtimer_irq;
85 const struct kvm_regs *cpu_reset;
86
87 switch (vcpu->arch.target) {
88 default:
89 if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
90 if (!cpu_has_32bit_el1())
91 return -EINVAL;
92 cpu_reset = &default_regs_reset32;
93 } else {
94 cpu_reset = &default_regs_reset;
95 }
96
97 cpu_vtimer_irq = &default_vtimer_irq;
98 break;
99 }
100
101 /* Reset core registers */
102 memcpy(vcpu_gp_regs(vcpu), cpu_reset, sizeof(*cpu_reset));
103
104 /* Reset system registers */
105 kvm_reset_sys_regs(vcpu);
106
107 /* Reset timer */
108 kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
109
110 return 0;
111 }
112