1 /*
2 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 */
18 #include <linux/compiler.h>
19 #include <linux/errno.h>
20 #include <linux/sched.h>
21 #include <linux/kvm_host.h>
22 #include <linux/kvm.h>
23
24 #include <asm/unified.h>
25 #include <asm/ptrace.h>
26 #include <asm/cputype.h>
27 #include <asm/kvm_arm.h>
28 #include <asm/kvm_coproc.h>
29 #include <asm/kvm_emulate.h>
30
31 #include <kvm/arm_arch_timer.h>
32
33 /******************************************************************************
34 * Cortex-A15 and Cortex-A7 Reset Values
35 */
36
37 static struct kvm_regs cortexa_regs_reset = {
38 .usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
39 };
40
41
42 /*******************************************************************************
43 * Exported reset function
44 */
45
46 /**
47 * kvm_reset_vcpu - sets core registers and cp15 registers to reset value
48 * @vcpu: The VCPU pointer
49 *
50 * This function finds the right table above and sets the registers on the
51 * virtual CPU struct to their architecturally defined reset values.
52 */
kvm_reset_vcpu(struct kvm_vcpu * vcpu)53 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
54 {
55 struct kvm_regs *reset_regs;
56
57 switch (vcpu->arch.target) {
58 case KVM_ARM_TARGET_CORTEX_A7:
59 case KVM_ARM_TARGET_CORTEX_A15:
60 reset_regs = &cortexa_regs_reset;
61 vcpu->arch.midr = read_cpuid_id();
62 break;
63 default:
64 return -ENODEV;
65 }
66
67 /* Reset core registers */
68 memcpy(&vcpu->arch.ctxt.gp_regs, reset_regs, sizeof(vcpu->arch.ctxt.gp_regs));
69
70 /* Reset CP15 registers */
71 kvm_reset_coprocs(vcpu);
72
73 /*
74 * Additional reset state handling that PSCI may have imposed on us.
75 * Must be done after all the sys_reg reset.
76 */
77 if (READ_ONCE(vcpu->arch.reset_state.reset)) {
78 unsigned long target_pc = vcpu->arch.reset_state.pc;
79
80 /* Gracefully handle Thumb2 entry point */
81 if (target_pc & 1) {
82 target_pc &= ~1UL;
83 vcpu_set_thumb(vcpu);
84 }
85
86 /* Propagate caller endianness */
87 if (vcpu->arch.reset_state.be)
88 kvm_vcpu_set_be(vcpu);
89
90 *vcpu_pc(vcpu) = target_pc;
91 vcpu_set_reg(vcpu, 0, vcpu->arch.reset_state.r0);
92
93 vcpu->arch.reset_state.reset = false;
94 }
95
96 /* Reset arch_timer context */
97 return kvm_timer_vcpu_reset(vcpu);
98 }
99