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_asm.h>
  33 #include <asm/kvm_coproc.h>
  34 #include <asm/kvm_mmu.h>
  35
  36 /*
  37  * ARMv8 Reset Values
  38  */
  39 static const struct kvm_regs default_regs_reset = {
  40         .regs.pstate = (PSR_MODE_EL1h | PSR_A_BIT | PSR_I_BIT |
  41                         PSR_F_BIT | PSR_D_BIT),
  42 };
  43
  44 static const struct kvm_regs default_regs_reset32 = {
  45         .regs.pstate = (COMPAT_PSR_MODE_SVC | COMPAT_PSR_A_BIT |
  46                         COMPAT_PSR_I_BIT | COMPAT_PSR_F_BIT),
  47 };
  48
  49 static bool cpu_has_32bit_el1(void)
  50 {
  51         u64 pfr0;
  52
  53         pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
  54         return !!(pfr0 & 0x20);
  55 }
  56
  57 /**
  58  * kvm_arch_dev_ioctl_check_extension
  59  *
  60  * We currently assume that the number of HW registers is uniform
  61  * across all CPUs (see cpuinfo_sanity_check).
  62  */
  63 int kvm_arch_dev_ioctl_check_extension(struct kvm *kvm, long ext)
  64 {
  65         int r;
  66
  67         switch (ext) {
  68         case KVM_CAP_ARM_EL1_32BIT:
  69                 r = cpu_has_32bit_el1();
  70                 break;
  71         case KVM_CAP_GUEST_DEBUG_HW_BPS:
  72                 r = get_num_brps();
  73                 break;
  74         case KVM_CAP_GUEST_DEBUG_HW_WPS:
  75                 r = get_num_wrps();
  76                 break;
  77         case KVM_CAP_ARM_PMU_V3:
  78                 r = kvm_arm_support_pmu_v3();
  79                 break;
  80         case KVM_CAP_SET_GUEST_DEBUG:
  81         case KVM_CAP_VCPU_ATTRIBUTES:
  82                 r = 1;
  83                 break;
  84         default:
  85                 r = 0;
  86         }
  87
  88         return r;
  89 }
  90
  91 /**
  92  * kvm_reset_vcpu - sets core registers and sys_regs to reset value
  93  * @vcpu: The VCPU pointer
  94  *
  95  * This function finds the right table above and sets the registers on
  96  * the virtual CPU struct to their architecturally defined reset
  97  * values.
  98  */
  99 int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 100 {
 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                 break;
 114         }
 115
 116         /* Reset core registers */
 117         memcpy(vcpu_gp_regs(vcpu), cpu_reset, sizeof(*cpu_reset));
 118
 119         /* Reset system registers */
 120         kvm_reset_sys_regs(vcpu);
 121
 122         /* Reset PMU */
 123         kvm_pmu_vcpu_reset(vcpu);
 124
 125         /* Default workaround setup is enabled (if supported) */
 126         if (kvm_arm_have_ssbd() == KVM_SSBD_KERNEL)
 127                 vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
 128
 129         /* Reset timer */
 130         return kvm_timer_vcpu_reset(vcpu);
 131 }