target-arm/kvm64.c

   1 /*
   2  * ARM implementation of KVM hooks, 64 bit specific code
   3  *
   4  * Copyright Mian-M. Hamayun 2013, Virtual Open Systems
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include <stdio.h>
  12 #include <sys/types.h>
  13 #include <sys/ioctl.h>
  14 #include <sys/mman.h>
  15
  16 #include <linux/kvm.h>
  17
  18 #include "qemu-common.h"
  19 #include "qemu/timer.h"
  20 #include "sysemu/sysemu.h"
  21 #include "sysemu/kvm.h"
  22 #include "kvm_arm.h"
  23 #include "cpu.h"
  24 #include "internals.h"
  25 #include "hw/arm/arm.h"
  26
  27 static inline void set_feature(uint64_t *features, int feature)
  28 {
  29     *features |= 1ULL << feature;
  30 }
  31
  32 bool kvm_arm_get_host_cpu_features(ARMHostCPUClass *ahcc)
  33 {
  34     /* Identify the feature bits corresponding to the host CPU, and
  35      * fill out the ARMHostCPUClass fields accordingly. To do this
  36      * we have to create a scratch VM, create a single CPU inside it,
  37      * and then query that CPU for the relevant ID registers.
  38      * For AArch64 we currently don't care about ID registers at
  39      * all; we just want to know the CPU type.
  40      */
  41     int fdarray[3];
  42     uint64_t features = 0;
  43     /* Old kernels may not know about the PREFERRED_TARGET ioctl: however
  44      * we know these will only support creating one kind of guest CPU,
  45      * which is its preferred CPU type. Fortunately these old kernels
  46      * support only a very limited number of CPUs.
  47      */
  48     static const uint32_t cpus_to_try[] = {
  49         KVM_ARM_TARGET_AEM_V8,
  50         KVM_ARM_TARGET_FOUNDATION_V8,
  51         KVM_ARM_TARGET_CORTEX_A57,
  52         QEMU_KVM_ARM_TARGET_NONE
  53     };
  54     struct kvm_vcpu_init init;
  55
  56     if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
  57         return false;
  58     }
  59
  60     ahcc->target = init.target;
  61     ahcc->dtb_compatible = "arm,arm-v8";
  62
  63     kvm_arm_destroy_scratch_host_vcpu(fdarray);
  64
  65    /* We can assume any KVM supporting CPU is at least a v8
  66      * with VFPv4+Neon; this in turn implies most of the other
  67      * feature bits.
  68      */
  69     set_feature(&features, ARM_FEATURE_V8);
  70     set_feature(&features, ARM_FEATURE_VFP4);
  71     set_feature(&features, ARM_FEATURE_NEON);
  72     set_feature(&features, ARM_FEATURE_AARCH64);
  73
  74     ahcc->features = features;
  75
  76     return true;
  77 }
  78
  79 int kvm_arch_init_vcpu(CPUState *cs)
  80 {
  81     int ret;
  82     ARMCPU *cpu = ARM_CPU(cs);
  83
  84     if (cpu->kvm_target == QEMU_KVM_ARM_TARGET_NONE ||
  85         !arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
  86         fprintf(stderr, "KVM is not supported for this guest CPU type\n");
  87         return -EINVAL;
  88     }
  89
  90     /* Determine init features for this CPU */
  91     memset(cpu->kvm_init_features, 0, sizeof(cpu->kvm_init_features));
  92     if (cpu->start_powered_off) {
  93         cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_POWER_OFF;
  94     }
  95     if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PSCI_0_2)) {
  96         cpu->psci_version = 2;
  97         cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_PSCI_0_2;
  98     }
  99
 100     /* Do KVM_ARM_VCPU_INIT ioctl */
 101     ret = kvm_arm_vcpu_init(cs);
 102     if (ret) {
 103         return ret;
 104     }
 105
 106     /* TODO : support for save/restore/reset of system regs via tuple list */
 107
 108     return 0;
 109 }
 110
 111 #define AARCH64_CORE_REG(x)   (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \
 112                  KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x))
 113
 114 int kvm_arch_put_registers(CPUState *cs, int level)
 115 {
 116     struct kvm_one_reg reg;
 117     uint64_t val;
 118     int i;
 119     int ret;
 120
 121     ARMCPU *cpu = ARM_CPU(cs);
 122     CPUARMState *env = &cpu->env;
 123
 124     for (i = 0; i < 31; i++) {
 125         reg.id = AARCH64_CORE_REG(regs.regs[i]);
 126         reg.addr = (uintptr_t) &env->xregs[i];
 127         ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 128         if (ret) {
 129             return ret;
 130         }
 131     }
 132
 133     /* KVM puts SP_EL0 in regs.sp and SP_EL1 in regs.sp_el1. On the
 134      * QEMU side we keep the current SP in xregs[31] as well.
 135      */
 136     aarch64_save_sp(env, 1);
 137
 138     reg.id = AARCH64_CORE_REG(regs.sp);
 139     reg.addr = (uintptr_t) &env->sp_el[0];
 140     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 141     if (ret) {
 142         return ret;
 143     }
 144
 145     reg.id = AARCH64_CORE_REG(sp_el1);
 146     reg.addr = (uintptr_t) &env->sp_el[1];
 147     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 148     if (ret) {
 149         return ret;
 150     }
 151
 152     /* Note that KVM thinks pstate is 64 bit but we use a uint32_t */
 153     val = pstate_read(env);
 154     reg.id = AARCH64_CORE_REG(regs.pstate);
 155     reg.addr = (uintptr_t) &val;
 156     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 157     if (ret) {
 158         return ret;
 159     }
 160
 161     reg.id = AARCH64_CORE_REG(regs.pc);
 162     reg.addr = (uintptr_t) &env->pc;
 163     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 164     if (ret) {
 165         return ret;
 166     }
 167
 168     reg.id = AARCH64_CORE_REG(elr_el1);
 169     reg.addr = (uintptr_t) &env->elr_el[1];
 170     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 171     if (ret) {
 172         return ret;
 173     }
 174
 175     for (i = 0; i < KVM_NR_SPSR; i++) {
 176         reg.id = AARCH64_CORE_REG(spsr[i]);
 177         reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
 178         ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 179         if (ret) {
 180             return ret;
 181         }
 182     }
 183
 184     /* TODO:
 185      * FP state
 186      * system registers
 187      */
 188     return ret;
 189 }
 190
 191 int kvm_arch_get_registers(CPUState *cs)
 192 {
 193     struct kvm_one_reg reg;
 194     uint64_t val;
 195     int i;
 196     int ret;
 197
 198     ARMCPU *cpu = ARM_CPU(cs);
 199     CPUARMState *env = &cpu->env;
 200
 201     for (i = 0; i < 31; i++) {
 202         reg.id = AARCH64_CORE_REG(regs.regs[i]);
 203         reg.addr = (uintptr_t) &env->xregs[i];
 204         ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 205         if (ret) {
 206             return ret;
 207         }
 208     }
 209
 210     reg.id = AARCH64_CORE_REG(regs.sp);
 211     reg.addr = (uintptr_t) &env->sp_el[0];
 212     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 213     if (ret) {
 214         return ret;
 215     }
 216
 217     reg.id = AARCH64_CORE_REG(sp_el1);
 218     reg.addr = (uintptr_t) &env->sp_el[1];
 219     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 220     if (ret) {
 221         return ret;
 222     }
 223
 224     reg.id = AARCH64_CORE_REG(regs.pstate);
 225     reg.addr = (uintptr_t) &val;
 226     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 227     if (ret) {
 228         return ret;
 229     }
 230     pstate_write(env, val);
 231
 232     /* KVM puts SP_EL0 in regs.sp and SP_EL1 in regs.sp_el1. On the
 233      * QEMU side we keep the current SP in xregs[31] as well.
 234      */
 235     aarch64_restore_sp(env, 1);
 236
 237     reg.id = AARCH64_CORE_REG(regs.pc);
 238     reg.addr = (uintptr_t) &env->pc;
 239     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 240     if (ret) {
 241         return ret;
 242     }
 243
 244     reg.id = AARCH64_CORE_REG(elr_el1);
 245     reg.addr = (uintptr_t) &env->elr_el[1];
 246     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 247     if (ret) {
 248         return ret;
 249     }
 250
 251     for (i = 0; i < KVM_NR_SPSR; i++) {
 252         reg.id = AARCH64_CORE_REG(spsr[i]);
 253         reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
 254         ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 255         if (ret) {
 256             return ret;
 257         }
 258     }
 259
 260     /* TODO: other registers */
 261     return ret;
 262 }
 263
 264 void kvm_arm_reset_vcpu(ARMCPU *cpu)
 265 {
 266     /* Re-init VCPU so that all registers are set to
 267      * their respective reset values.
 268      */
 269     kvm_arm_vcpu_init(CPU(cpu));
 270 }