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 #include <linux/hw_breakpoint.h>
  26
  27 #include <kvm/arm_arch_timer.h>
  28
  29 #include <asm/cputype.h>
  30 #include <asm/ptrace.h>
  31 #include <asm/kvm_arm.h>
  32 #include <asm/kvm_coproc.h>
  33
  34 /*
  35  * ARMv8 Reset Values
  36  */
  37 static const struct kvm_regs default_regs_reset = {
  38         .regs.pstate = (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT |
  39                         PSR_F_BIT | PSR_D_BIT),
  40 };
  41
  42 static const struct kvm_regs default_regs_reset32 = {
  43         .regs.pstate = (COMPAT_PSR_MODE_SVC | COMPAT_PSR_A_BIT |
  44                         COMPAT_PSR_I_BIT | COMPAT_PSR_F_BIT),
  45 };
  46
  47 static const struct kvm_irq_level default_vtimer_irq = {
  48         .irq    = 27,
  49         .level  = 1,
  50 };
  51
  52 static bool cpu_has_32bit_el1(void)
  53 {
  54         u64 pfr0;
  55
  56         pfr0 = read_cpuid(ID_AA64PFR0_EL1);
  57         return !!(pfr0 & 0x20);
  58 }
  59
  60 /**
  61  * kvm_arch_dev_ioctl_check_extension
  62  *
  63  * We currently assume that the number of HW registers is uniform
  64  * across all CPUs (see cpuinfo_sanity_check).
  65  */
  66 int kvm_arch_dev_ioctl_check_extension(long ext)
  67 {
  68         int r;
  69
  70         switch (ext) {
  71         case KVM_CAP_ARM_EL1_32BIT:
  72                 r = cpu_has_32bit_el1();
  73                 break;
  74         case KVM_CAP_GUEST_DEBUG_HW_BPS:
  75                 r = get_num_brps();
  76                 break;
  77         case KVM_CAP_GUEST_DEBUG_HW_WPS:
  78                 r = get_num_wrps();
  79                 break;
  80         case KVM_CAP_SET_GUEST_DEBUG:
  81                 r = 1;
  82                 break;
  83         default:
  84                 r = 0;
  85         }
  86
  87         return r;
  88 }
  89
  90 /**
  91  * kvm_reset_vcpu - sets core registers and sys_regs to reset value
  92  * @vcpu: The VCPU pointer
  93  *
  94  * This function finds the right table above and sets the registers on
  95  * the virtual CPU struct to their architectually defined reset
  96  * values.
  97  */
  98 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
  99 {
 100         const struct kvm_irq_level *cpu_vtimer_irq;
 101         const struct kvm_regs *cpu_reset;
 102
 103         switch (vcpu->arch.target) {
 104         default:
 105                 if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
 106                         if (!cpu_has_32bit_el1())
 107                                 return -EINVAL;
 108                         cpu_reset = &default_regs_reset32;
 109                 } else {
 110                         cpu_reset = &default_regs_reset;
 111                 }
 112
 113                 cpu_vtimer_irq = &default_vtimer_irq;
 114                 break;
 115         }
 116
 117         /* Reset core registers */
 118         memcpy(vcpu_gp_regs(vcpu), cpu_reset, sizeof(*cpu_reset));
 119
 120         /* Reset system registers */
 121         kvm_reset_sys_regs(vcpu);
 122
 123         /* Reset timer */
 124         return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
 125 }