| 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 | |
| 17 | #include "x86.h" |
| 18 | |
| 19 | #include <asm/uaccess.h> |
| 20 | |
| 21 | /* |
| 22 | * List of msr numbers which we expose to userspace through KVM_GET_MSRS |
| 23 | * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. |
| 24 | * |
| 25 | * This list is modified at module load time to reflect the |
| 26 | * capabilities of the host cpu. |
| 27 | */ |
| 28 | static u32 msrs_to_save[] = { |
| 29 | MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, |
| 30 | MSR_K6_STAR, |
| 31 | #ifdef CONFIG_X86_64 |
| 32 | MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR, |
| 33 | #endif |
| 34 | MSR_IA32_TIME_STAMP_COUNTER, |
| 35 | }; |
| 36 | |
| 37 | static unsigned num_msrs_to_save; |
| 38 | |
| 39 | static u32 emulated_msrs[] = { |
| 40 | MSR_IA32_MISC_ENABLE, |
| 41 | }; |
| 42 | |
| 43 | long kvm_arch_dev_ioctl(struct file *filp, |
| 44 | unsigned int ioctl, unsigned long arg) |
| 45 | { |
| 46 | void __user *argp = (void __user *)arg; |
| 47 | long r; |
| 48 | |
| 49 | switch (ioctl) { |
| 50 | case KVM_GET_MSR_INDEX_LIST: { |
| 51 | struct kvm_msr_list __user *user_msr_list = argp; |
| 52 | struct kvm_msr_list msr_list; |
| 53 | unsigned n; |
| 54 | |
| 55 | r = -EFAULT; |
| 56 | if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list)) |
| 57 | goto out; |
| 58 | n = msr_list.nmsrs; |
| 59 | msr_list.nmsrs = num_msrs_to_save + ARRAY_SIZE(emulated_msrs); |
| 60 | if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list)) |
| 61 | goto out; |
| 62 | r = -E2BIG; |
| 63 | if (n < num_msrs_to_save) |
| 64 | goto out; |
| 65 | r = -EFAULT; |
| 66 | if (copy_to_user(user_msr_list->indices, &msrs_to_save, |
| 67 | num_msrs_to_save * sizeof(u32))) |
| 68 | goto out; |
| 69 | if (copy_to_user(user_msr_list->indices |
| 70 | + num_msrs_to_save * sizeof(u32), |
| 71 | &emulated_msrs, |
| 72 | ARRAY_SIZE(emulated_msrs) * sizeof(u32))) |
| 73 | goto out; |
| 74 | r = 0; |
| 75 | break; |
| 76 | } |
| 77 | default: |
| 78 | r = -EINVAL; |
| 79 | } |
| 80 | out: |
| 81 | return r; |
| 82 | } |
| 83 | |
| 84 | static __init void kvm_init_msr_list(void) |
| 85 | { |
| 86 | u32 dummy[2]; |
| 87 | unsigned i, j; |
| 88 | |
| 89 | for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) { |
| 90 | if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) |
| 91 | continue; |
| 92 | if (j < i) |
| 93 | msrs_to_save[j] = msrs_to_save[i]; |
| 94 | j++; |
| 95 | } |
| 96 | num_msrs_to_save = j; |
| 97 | } |
| 98 | |
| 99 | __init void kvm_arch_init(void) |
| 100 | { |
| 101 | kvm_init_msr_list(); |
| 102 | } |