Carsten Otte | 043405e | 2007-10-10 17:16:19 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Kernel-based Virtual Machine driver for Linux |
| 3 | * |
| 4 | * derived from drivers/kvm/kvm_main.c |
| 5 | * |
| 6 | * Copyright (C) 2006 Qumranet, Inc. |
| 7 | * |
| 8 | * Authors: |
| 9 | * Avi Kivity <avi@qumranet.com> |
| 10 | * Yaniv Kamay <yaniv@qumranet.com> |
| 11 | * |
| 12 | * This work is licensed under the terms of the GNU GPL, version 2. See |
| 13 | * the COPYING file in the top-level directory. |
| 14 | * |
| 15 | */ |
| 16 | |
Carsten Otte | 313a3dc | 2007-10-11 19:16:52 +0200 | [diff] [blame^] | 17 | #include "kvm.h" |
Carsten Otte | 043405e | 2007-10-10 17:16:19 +0200 | [diff] [blame] | 18 | #include "x86.h" |
Carsten Otte | 313a3dc | 2007-10-11 19:16:52 +0200 | [diff] [blame^] | 19 | #include "irq.h" |
| 20 | |
| 21 | #include <linux/kvm.h> |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/vmalloc.h> |
Carsten Otte | 043405e | 2007-10-10 17:16:19 +0200 | [diff] [blame] | 24 | |
| 25 | #include <asm/uaccess.h> |
| 26 | |
Carsten Otte | 313a3dc | 2007-10-11 19:16:52 +0200 | [diff] [blame^] | 27 | #define MAX_IO_MSRS 256 |
| 28 | |
Carsten Otte | 043405e | 2007-10-10 17:16:19 +0200 | [diff] [blame] | 29 | /* |
| 30 | * List of msr numbers which we expose to userspace through KVM_GET_MSRS |
| 31 | * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. |
| 32 | * |
| 33 | * This list is modified at module load time to reflect the |
| 34 | * capabilities of the host cpu. |
| 35 | */ |
| 36 | static u32 msrs_to_save[] = { |
| 37 | MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, |
| 38 | MSR_K6_STAR, |
| 39 | #ifdef CONFIG_X86_64 |
| 40 | MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR, |
| 41 | #endif |
| 42 | MSR_IA32_TIME_STAMP_COUNTER, |
| 43 | }; |
| 44 | |
| 45 | static unsigned num_msrs_to_save; |
| 46 | |
| 47 | static u32 emulated_msrs[] = { |
| 48 | MSR_IA32_MISC_ENABLE, |
| 49 | }; |
| 50 | |
Carsten Otte | 313a3dc | 2007-10-11 19:16:52 +0200 | [diff] [blame^] | 51 | /* |
| 52 | * Adapt set_msr() to msr_io()'s calling convention |
| 53 | */ |
| 54 | static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data) |
| 55 | { |
| 56 | return kvm_set_msr(vcpu, index, *data); |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Read or write a bunch of msrs. All parameters are kernel addresses. |
| 61 | * |
| 62 | * @return number of msrs set successfully. |
| 63 | */ |
| 64 | static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs, |
| 65 | struct kvm_msr_entry *entries, |
| 66 | int (*do_msr)(struct kvm_vcpu *vcpu, |
| 67 | unsigned index, u64 *data)) |
| 68 | { |
| 69 | int i; |
| 70 | |
| 71 | vcpu_load(vcpu); |
| 72 | |
| 73 | for (i = 0; i < msrs->nmsrs; ++i) |
| 74 | if (do_msr(vcpu, entries[i].index, &entries[i].data)) |
| 75 | break; |
| 76 | |
| 77 | vcpu_put(vcpu); |
| 78 | |
| 79 | return i; |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * Read or write a bunch of msrs. Parameters are user addresses. |
| 84 | * |
| 85 | * @return number of msrs set successfully. |
| 86 | */ |
| 87 | static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs, |
| 88 | int (*do_msr)(struct kvm_vcpu *vcpu, |
| 89 | unsigned index, u64 *data), |
| 90 | int writeback) |
| 91 | { |
| 92 | struct kvm_msrs msrs; |
| 93 | struct kvm_msr_entry *entries; |
| 94 | int r, n; |
| 95 | unsigned size; |
| 96 | |
| 97 | r = -EFAULT; |
| 98 | if (copy_from_user(&msrs, user_msrs, sizeof msrs)) |
| 99 | goto out; |
| 100 | |
| 101 | r = -E2BIG; |
| 102 | if (msrs.nmsrs >= MAX_IO_MSRS) |
| 103 | goto out; |
| 104 | |
| 105 | r = -ENOMEM; |
| 106 | size = sizeof(struct kvm_msr_entry) * msrs.nmsrs; |
| 107 | entries = vmalloc(size); |
| 108 | if (!entries) |
| 109 | goto out; |
| 110 | |
| 111 | r = -EFAULT; |
| 112 | if (copy_from_user(entries, user_msrs->entries, size)) |
| 113 | goto out_free; |
| 114 | |
| 115 | r = n = __msr_io(vcpu, &msrs, entries, do_msr); |
| 116 | if (r < 0) |
| 117 | goto out_free; |
| 118 | |
| 119 | r = -EFAULT; |
| 120 | if (writeback && copy_to_user(user_msrs->entries, entries, size)) |
| 121 | goto out_free; |
| 122 | |
| 123 | r = n; |
| 124 | |
| 125 | out_free: |
| 126 | vfree(entries); |
| 127 | out: |
| 128 | return r; |
| 129 | } |
| 130 | |
Carsten Otte | 043405e | 2007-10-10 17:16:19 +0200 | [diff] [blame] | 131 | long kvm_arch_dev_ioctl(struct file *filp, |
| 132 | unsigned int ioctl, unsigned long arg) |
| 133 | { |
| 134 | void __user *argp = (void __user *)arg; |
| 135 | long r; |
| 136 | |
| 137 | switch (ioctl) { |
| 138 | case KVM_GET_MSR_INDEX_LIST: { |
| 139 | struct kvm_msr_list __user *user_msr_list = argp; |
| 140 | struct kvm_msr_list msr_list; |
| 141 | unsigned n; |
| 142 | |
| 143 | r = -EFAULT; |
| 144 | if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list)) |
| 145 | goto out; |
| 146 | n = msr_list.nmsrs; |
| 147 | msr_list.nmsrs = num_msrs_to_save + ARRAY_SIZE(emulated_msrs); |
| 148 | if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list)) |
| 149 | goto out; |
| 150 | r = -E2BIG; |
| 151 | if (n < num_msrs_to_save) |
| 152 | goto out; |
| 153 | r = -EFAULT; |
| 154 | if (copy_to_user(user_msr_list->indices, &msrs_to_save, |
| 155 | num_msrs_to_save * sizeof(u32))) |
| 156 | goto out; |
| 157 | if (copy_to_user(user_msr_list->indices |
| 158 | + num_msrs_to_save * sizeof(u32), |
| 159 | &emulated_msrs, |
| 160 | ARRAY_SIZE(emulated_msrs) * sizeof(u32))) |
| 161 | goto out; |
| 162 | r = 0; |
| 163 | break; |
| 164 | } |
| 165 | default: |
| 166 | r = -EINVAL; |
| 167 | } |
| 168 | out: |
| 169 | return r; |
| 170 | } |
| 171 | |
Carsten Otte | 313a3dc | 2007-10-11 19:16:52 +0200 | [diff] [blame^] | 172 | void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) |
| 173 | { |
| 174 | kvm_x86_ops->vcpu_load(vcpu, cpu); |
| 175 | } |
| 176 | |
| 177 | void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) |
| 178 | { |
| 179 | kvm_x86_ops->vcpu_put(vcpu); |
| 180 | } |
| 181 | |
| 182 | static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) |
| 183 | { |
| 184 | u64 efer; |
| 185 | int i; |
| 186 | struct kvm_cpuid_entry *e, *entry; |
| 187 | |
| 188 | rdmsrl(MSR_EFER, efer); |
| 189 | entry = NULL; |
| 190 | for (i = 0; i < vcpu->cpuid_nent; ++i) { |
| 191 | e = &vcpu->cpuid_entries[i]; |
| 192 | if (e->function == 0x80000001) { |
| 193 | entry = e; |
| 194 | break; |
| 195 | } |
| 196 | } |
| 197 | if (entry && (entry->edx & (1 << 20)) && !(efer & EFER_NX)) { |
| 198 | entry->edx &= ~(1 << 20); |
| 199 | printk(KERN_INFO "kvm: guest NX capability removed\n"); |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | static int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, |
| 204 | struct kvm_cpuid *cpuid, |
| 205 | struct kvm_cpuid_entry __user *entries) |
| 206 | { |
| 207 | int r; |
| 208 | |
| 209 | r = -E2BIG; |
| 210 | if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) |
| 211 | goto out; |
| 212 | r = -EFAULT; |
| 213 | if (copy_from_user(&vcpu->cpuid_entries, entries, |
| 214 | cpuid->nent * sizeof(struct kvm_cpuid_entry))) |
| 215 | goto out; |
| 216 | vcpu->cpuid_nent = cpuid->nent; |
| 217 | cpuid_fix_nx_cap(vcpu); |
| 218 | return 0; |
| 219 | |
| 220 | out: |
| 221 | return r; |
| 222 | } |
| 223 | |
| 224 | static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu, |
| 225 | struct kvm_lapic_state *s) |
| 226 | { |
| 227 | vcpu_load(vcpu); |
| 228 | memcpy(s->regs, vcpu->apic->regs, sizeof *s); |
| 229 | vcpu_put(vcpu); |
| 230 | |
| 231 | return 0; |
| 232 | } |
| 233 | |
| 234 | static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu, |
| 235 | struct kvm_lapic_state *s) |
| 236 | { |
| 237 | vcpu_load(vcpu); |
| 238 | memcpy(vcpu->apic->regs, s->regs, sizeof *s); |
| 239 | kvm_apic_post_state_restore(vcpu); |
| 240 | vcpu_put(vcpu); |
| 241 | |
| 242 | return 0; |
| 243 | } |
| 244 | |
| 245 | long kvm_arch_vcpu_ioctl(struct file *filp, |
| 246 | unsigned int ioctl, unsigned long arg) |
| 247 | { |
| 248 | struct kvm_vcpu *vcpu = filp->private_data; |
| 249 | void __user *argp = (void __user *)arg; |
| 250 | int r; |
| 251 | |
| 252 | switch (ioctl) { |
| 253 | case KVM_GET_LAPIC: { |
| 254 | struct kvm_lapic_state lapic; |
| 255 | |
| 256 | memset(&lapic, 0, sizeof lapic); |
| 257 | r = kvm_vcpu_ioctl_get_lapic(vcpu, &lapic); |
| 258 | if (r) |
| 259 | goto out; |
| 260 | r = -EFAULT; |
| 261 | if (copy_to_user(argp, &lapic, sizeof lapic)) |
| 262 | goto out; |
| 263 | r = 0; |
| 264 | break; |
| 265 | } |
| 266 | case KVM_SET_LAPIC: { |
| 267 | struct kvm_lapic_state lapic; |
| 268 | |
| 269 | r = -EFAULT; |
| 270 | if (copy_from_user(&lapic, argp, sizeof lapic)) |
| 271 | goto out; |
| 272 | r = kvm_vcpu_ioctl_set_lapic(vcpu, &lapic);; |
| 273 | if (r) |
| 274 | goto out; |
| 275 | r = 0; |
| 276 | break; |
| 277 | } |
| 278 | case KVM_SET_CPUID: { |
| 279 | struct kvm_cpuid __user *cpuid_arg = argp; |
| 280 | struct kvm_cpuid cpuid; |
| 281 | |
| 282 | r = -EFAULT; |
| 283 | if (copy_from_user(&cpuid, cpuid_arg, sizeof cpuid)) |
| 284 | goto out; |
| 285 | r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries); |
| 286 | if (r) |
| 287 | goto out; |
| 288 | break; |
| 289 | } |
| 290 | case KVM_GET_MSRS: |
| 291 | r = msr_io(vcpu, argp, kvm_get_msr, 1); |
| 292 | break; |
| 293 | case KVM_SET_MSRS: |
| 294 | r = msr_io(vcpu, argp, do_set_msr, 0); |
| 295 | break; |
| 296 | default: |
| 297 | r = -EINVAL; |
| 298 | } |
| 299 | out: |
| 300 | return r; |
| 301 | } |
| 302 | |
Carsten Otte | 043405e | 2007-10-10 17:16:19 +0200 | [diff] [blame] | 303 | static __init void kvm_init_msr_list(void) |
| 304 | { |
| 305 | u32 dummy[2]; |
| 306 | unsigned i, j; |
| 307 | |
| 308 | for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) { |
| 309 | if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) |
| 310 | continue; |
| 311 | if (j < i) |
| 312 | msrs_to_save[j] = msrs_to_save[i]; |
| 313 | j++; |
| 314 | } |
| 315 | num_msrs_to_save = j; |
| 316 | } |
| 317 | |
| 318 | __init void kvm_arch_init(void) |
| 319 | { |
| 320 | kvm_init_msr_list(); |
| 321 | } |