arch/arm64/kvm/reset.c

   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
  51 static bool cpu_has_32bit_el1(void)
  52 {
  53         u64 pfr0;
  54
  55         pfr0 = read_cpuid(ID_AA64PFR0_EL1);
  56         return !!(pfr0 & 0x20);
  57 }
  58
  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  */
  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 }