arch/arm/kvm/reset.c

   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
  30 #include <kvm/arm_arch_timer.h>
  31
  32 /******************************************************************************
  33  * Cortex-A15 Reset Values
  34  */
  35
  36 static const int a15_max_cpu_idx = 3;
  37
  38 static struct kvm_regs a15_regs_reset = {
  39         .usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
  40 };
  41
  42 static const struct kvm_irq_level a15_vtimer_irq = {
  43         { .irq = 27 },
  44         .level = 1,
  45 };
  46
  47
  48 /*******************************************************************************
  49  * Exported reset function
  50  */
  51
  52 /**
  53  * kvm_reset_vcpu - sets core registers and cp15 registers to reset value
  54  * @vcpu: The VCPU pointer
  55  *
  56  * This function finds the right table above and sets the registers on the
  57  * virtual CPU struct to their architectually defined reset values.
  58  */
  59 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
  60 {
  61         struct kvm_regs *reset_regs;
  62         const struct kvm_irq_level *cpu_vtimer_irq;
  63
  64         switch (vcpu->arch.target) {
  65         case KVM_ARM_TARGET_CORTEX_A15:
  66                 if (vcpu->vcpu_id > a15_max_cpu_idx)
  67                         return -EINVAL;
  68                 reset_regs = &a15_regs_reset;
  69                 vcpu->arch.midr = read_cpuid_id();
  70                 cpu_vtimer_irq = &a15_vtimer_irq;
  71                 break;
  72         default:
  73                 return -ENODEV;
  74         }
  75
  76         /* Reset core registers */
  77         memcpy(&vcpu->arch.regs, reset_regs, sizeof(vcpu->arch.regs));
  78
  79         /* Reset CP15 registers */
  80         kvm_reset_coprocs(vcpu);
  81
  82         /* Reset arch_timer context */
  83         kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
  84
  85         return 0;
  86 }