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 /******************************************************************************
  31  * Cortex-A15 Reset Values
  32  */
  33
  34 static const int a15_max_cpu_idx = 3;
  35
  36 static struct kvm_regs a15_regs_reset = {
  37         .usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
  38 };
  39
  40
  41 /*******************************************************************************
  42  * Exported reset function
  43  */
  44
  45 /**
  46  * kvm_reset_vcpu - sets core registers and cp15 registers to reset value
  47  * @vcpu: The VCPU pointer
  48  *
  49  * This function finds the right table above and sets the registers on the
  50  * virtual CPU struct to their architectually defined reset values.
  51  */
  52 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
  53 {
  54         struct kvm_regs *cpu_reset;
  55
  56         switch (vcpu->arch.target) {
  57         case KVM_ARM_TARGET_CORTEX_A15:
  58                 if (vcpu->vcpu_id > a15_max_cpu_idx)
  59                         return -EINVAL;
  60                 cpu_reset = &a15_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.regs, cpu_reset, sizeof(vcpu->arch.regs));
  69
  70         /* Reset CP15 registers */
  71         kvm_reset_coprocs(vcpu);
  72
  73         return 0;
  74 }