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 "hw/arm/arm.h"
  25
  26 static inline void set_feature(uint64_t *features, int feature)
  27 {
  28     *features |= 1ULL << feature;
  29 }
  30
  31 bool kvm_arm_get_host_cpu_features(ARMHostCPUClass *ahcc)
  32 {
  33     /* Identify the feature bits corresponding to the host CPU, and
  34      * fill out the ARMHostCPUClass fields accordingly. To do this
  35      * we have to create a scratch VM, create a single CPU inside it,
  36      * and then query that CPU for the relevant ID registers.
  37      * For AArch64 we currently don't care about ID registers at
  38      * all; we just want to know the CPU type.
  39      */
  40     int fdarray[3];
  41     uint64_t features = 0;
  42     /* Old kernels may not know about the PREFERRED_TARGET ioctl: however
  43      * we know these will only support creating one kind of guest CPU,
  44      * which is its preferred CPU type. Fortunately these old kernels
  45      * support only a very limited number of CPUs.
  46      */
  47     static const uint32_t cpus_to_try[] = {
  48         KVM_ARM_TARGET_AEM_V8,
  49         KVM_ARM_TARGET_FOUNDATION_V8,
  50         KVM_ARM_TARGET_CORTEX_A57,
  51         QEMU_KVM_ARM_TARGET_NONE
  52     };
  53     struct kvm_vcpu_init init;
  54
  55     if (!kvm_arm_create_scratch_host_vcpu(cpus_to_try, fdarray, &init)) {
  56         return false;
  57     }
  58
  59     ahcc->target = init.target;
  60     ahcc->dtb_compatible = "arm,arm-v8";
  61
  62     kvm_arm_destroy_scratch_host_vcpu(fdarray);
  63
  64    /* We can assume any KVM supporting CPU is at least a v8
  65      * with VFPv4+Neon; this in turn implies most of the other
  66      * feature bits.
  67      */
  68     set_feature(&features, ARM_FEATURE_V8);
  69     set_feature(&features, ARM_FEATURE_VFP4);
  70     set_feature(&features, ARM_FEATURE_NEON);
  71     set_feature(&features, ARM_FEATURE_AARCH64);
  72
  73     ahcc->features = features;
  74
  75     return true;
  76 }
  77
  78 int kvm_arch_init_vcpu(CPUState *cs)
  79 {
  80     int ret;
  81     ARMCPU *cpu = ARM_CPU(cs);
  82
  83     if (cpu->kvm_target == QEMU_KVM_ARM_TARGET_NONE ||
  84         !arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {
  85         fprintf(stderr, "KVM is not supported for this guest CPU type\n");
  86         return -EINVAL;
  87     }
  88
  89     /* Determine init features for this CPU */
  90     memset(cpu->kvm_init_features, 0, sizeof(cpu->kvm_init_features));
  91     if (cpu->start_powered_off) {
  92         cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_POWER_OFF;
  93     }
  94     if (kvm_check_extension(cs->kvm_state, KVM_CAP_ARM_PSCI_0_2)) {
  95         cpu->kvm_init_features[0] |= 1 << KVM_ARM_VCPU_PSCI_0_2;
  96     }
  97
  98     /* Do KVM_ARM_VCPU_INIT ioctl */
  99     ret = kvm_arm_vcpu_init(cs);
 100     if (ret) {
 101         return ret;
 102     }
 103
 104     /* TODO : support for save/restore/reset of system regs via tuple list */
 105
 106     return 0;
 107 }
 108
 109 #define AARCH64_CORE_REG(x)   (KVM_REG_ARM64 | KVM_REG_SIZE_U64 | \
 110                  KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(x))
 111
 112 int kvm_arch_put_registers(CPUState *cs, int level)
 113 {
 114     struct kvm_one_reg reg;
 115     uint64_t val;
 116     int i;
 117     int ret;
 118
 119     ARMCPU *cpu = ARM_CPU(cs);
 120     CPUARMState *env = &cpu->env;
 121
 122     for (i = 0; i < 31; i++) {
 123         reg.id = AARCH64_CORE_REG(regs.regs[i]);
 124         reg.addr = (uintptr_t) &env->xregs[i];
 125         ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 126         if (ret) {
 127             return ret;
 128         }
 129     }
 130
 131     /* KVM puts SP_EL0 in regs.sp and SP_EL1 in regs.sp_el1. On the
 132      * QEMU side we keep the current SP in xregs[31] as well.
 133      */
 134     if (env->pstate & PSTATE_SP) {
 135         env->sp_el[1] = env->xregs[31];
 136     } else {
 137         env->sp_el[0] = env->xregs[31];
 138     }
 139
 140     reg.id = AARCH64_CORE_REG(regs.sp);
 141     reg.addr = (uintptr_t) &env->sp_el[0];
 142     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 143     if (ret) {
 144         return ret;
 145     }
 146
 147     reg.id = AARCH64_CORE_REG(sp_el1);
 148     reg.addr = (uintptr_t) &env->sp_el[1];
 149     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 150     if (ret) {
 151         return ret;
 152     }
 153
 154     /* Note that KVM thinks pstate is 64 bit but we use a uint32_t */
 155     val = pstate_read(env);
 156     reg.id = AARCH64_CORE_REG(regs.pstate);
 157     reg.addr = (uintptr_t) &val;
 158     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 159     if (ret) {
 160         return ret;
 161     }
 162
 163     reg.id = AARCH64_CORE_REG(regs.pc);
 164     reg.addr = (uintptr_t) &env->pc;
 165     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 166     if (ret) {
 167         return ret;
 168     }
 169
 170     reg.id = AARCH64_CORE_REG(elr_el1);
 171     reg.addr = (uintptr_t) &env->elr_el[1];
 172     ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 173     if (ret) {
 174         return ret;
 175     }
 176
 177     for (i = 0; i < KVM_NR_SPSR; i++) {
 178         reg.id = AARCH64_CORE_REG(spsr[i]);
 179         reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
 180         ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, &reg);
 181         if (ret) {
 182             return ret;
 183         }
 184     }
 185
 186     /* TODO:
 187      * FP state
 188      * system registers
 189      */
 190     return ret;
 191 }
 192
 193 int kvm_arch_get_registers(CPUState *cs)
 194 {
 195     struct kvm_one_reg reg;
 196     uint64_t val;
 197     int i;
 198     int ret;
 199
 200     ARMCPU *cpu = ARM_CPU(cs);
 201     CPUARMState *env = &cpu->env;
 202
 203     for (i = 0; i < 31; i++) {
 204         reg.id = AARCH64_CORE_REG(regs.regs[i]);
 205         reg.addr = (uintptr_t) &env->xregs[i];
 206         ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 207         if (ret) {
 208             return ret;
 209         }
 210     }
 211
 212     reg.id = AARCH64_CORE_REG(regs.sp);
 213     reg.addr = (uintptr_t) &env->sp_el[0];
 214     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 215     if (ret) {
 216         return ret;
 217     }
 218
 219     reg.id = AARCH64_CORE_REG(sp_el1);
 220     reg.addr = (uintptr_t) &env->sp_el[1];
 221     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 222     if (ret) {
 223         return ret;
 224     }
 225
 226     reg.id = AARCH64_CORE_REG(regs.pstate);
 227     reg.addr = (uintptr_t) &val;
 228     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 229     if (ret) {
 230         return ret;
 231     }
 232     pstate_write(env, val);
 233
 234     /* KVM puts SP_EL0 in regs.sp and SP_EL1 in regs.sp_el1. On the
 235      * QEMU side we keep the current SP in xregs[31] as well.
 236      */
 237     if (env->pstate & PSTATE_SP) {
 238         env->xregs[31] = env->sp_el[1];
 239     } else {
 240         env->xregs[31] = env->sp_el[0];
 241     }
 242
 243     reg.id = AARCH64_CORE_REG(regs.pc);
 244     reg.addr = (uintptr_t) &env->pc;
 245     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 246     if (ret) {
 247         return ret;
 248     }
 249
 250     reg.id = AARCH64_CORE_REG(elr_el1);
 251     reg.addr = (uintptr_t) &env->elr_el[1];
 252     ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 253     if (ret) {
 254         return ret;
 255     }
 256
 257     for (i = 0; i < KVM_NR_SPSR; i++) {
 258         reg.id = AARCH64_CORE_REG(spsr[i]);
 259         reg.addr = (uintptr_t) &env->banked_spsr[i - 1];
 260         ret = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, &reg);
 261         if (ret) {
 262             return ret;
 263         }
 264     }
 265
 266     /* TODO: other registers */
 267     return ret;
 268 }
 269
 270 void kvm_arm_reset_vcpu(ARMCPU *cpu)
 271 {
 272     /* Re-init VCPU so that all registers are set to
 273      * their respective reset values.
 274      */
 275     kvm_arm_vcpu_init(CPU(cpu));
 276 }