diff options
| -rw-r--r-- | drivers/kvm/kvm_main.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 4621b4ee674..bc2e6c19f85 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -1417,6 +1417,9 @@ static int kvm_dev_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs) /* * List of msr numbers which we expose to userspace through KVM_GET_MSRS * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST. + * + * This list is modified at module load time to reflect the + * capabilities of the host cpu. */ static u32 msrs_to_save[] = { MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP, @@ -1427,6 +1430,22 @@ static u32 msrs_to_save[] = { MSR_IA32_TIME_STAMP_COUNTER, }; +static unsigned num_msrs_to_save; + +static __init void kvm_init_msr_list(void) +{ + u32 dummy[2]; + unsigned i, j; + + for (i = j = 0; i < ARRAY_SIZE(msrs_to_save); i++) { + if (rdmsr_safe(msrs_to_save[i], &dummy[0], &dummy[1]) < 0) + continue; + if (j < i) + msrs_to_save[j] = msrs_to_save[i]; + j++; + } + num_msrs_to_save = j; +} /* * Adapt set_msr() to msr_io()'s calling convention @@ -1735,15 +1754,15 @@ static long kvm_dev_ioctl(struct file *filp, if (copy_from_user(&msr_list, user_msr_list, sizeof msr_list)) goto out; n = msr_list.nmsrs; - msr_list.nmsrs = ARRAY_SIZE(msrs_to_save); + msr_list.nmsrs = num_msrs_to_save; if (copy_to_user(user_msr_list, &msr_list, sizeof msr_list)) goto out; r = -E2BIG; - if (n < ARRAY_SIZE(msrs_to_save)) + if (n < num_msrs_to_save) goto out; r = -EFAULT; if (copy_to_user(user_msr_list->indices, &msrs_to_save, - sizeof msrs_to_save)) + num_msrs_to_save * sizeof(u32))) goto out; r = 0; } @@ -1894,6 +1913,8 @@ static __init int kvm_init(void) kvm_init_debug(); + kvm_init_msr_list(); + if ((bad_page = alloc_page(GFP_KERNEL)) == NULL) { r = -ENOMEM; goto out; |