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
25 static 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 */
41 int 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 }