diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 7 | ||||
| -rw-r--r-- | arch/x86/kvm/svm.c | 20 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 35 |
3 files changed, 62 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index da0a8ce3a13..bd57639fd5d 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -655,6 +655,13 @@ u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn); extern bool tdp_enabled; +/* control of guest tsc rate supported? */ +extern bool kvm_has_tsc_control; +/* minimum supported tsc_khz for guests */ +extern u32 kvm_min_guest_tsc_khz; +/* maximum supported tsc_khz for guests */ +extern u32 kvm_max_guest_tsc_khz; + enum emulation_result { EMULATE_DONE, /* no further processing */ EMULATE_DO_MMIO, /* kvm_run filled with mmio request */ diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 8c4549bef4e..a9887376243 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -64,6 +64,8 @@ MODULE_LICENSE("GPL"); #define DEBUGCTL_RESERVED_BITS (~(0x3fULL)) #define TSC_RATIO_RSVD 0xffffff0000000000ULL +#define TSC_RATIO_MIN 0x0000000000000001ULL +#define TSC_RATIO_MAX 0x000000ffffffffffULL static bool erratum_383_found __read_mostly; @@ -189,6 +191,7 @@ static int nested_svm_intercept(struct vcpu_svm *svm); static int nested_svm_vmexit(struct vcpu_svm *svm); static int nested_svm_check_exception(struct vcpu_svm *svm, unsigned nr, bool has_error_code, u32 error_code); +static u64 __scale_tsc(u64 ratio, u64 tsc); enum { VMCB_INTERCEPTS, /* Intercept vectors, TSC offset, @@ -798,6 +801,23 @@ static __init int svm_hardware_setup(void) if (boot_cpu_has(X86_FEATURE_FXSR_OPT)) kvm_enable_efer_bits(EFER_FFXSR); + if (boot_cpu_has(X86_FEATURE_TSCRATEMSR)) { + u64 max; + + kvm_has_tsc_control = true; + + /* + * Make sure the user can only configure tsc_khz values that + * fit into a signed integer. + * A min value is not calculated needed because it will always + * be 1 on all machines and a value of 0 is used to disable + * tsc-scaling for the vcpu. + */ + max = min(0x7fffffffULL, __scale_tsc(tsc_khz, TSC_RATIO_MAX)); + + kvm_max_guest_tsc_khz = max; + } + if (nested) { printk(KERN_INFO "kvm: Nested Virtualization enabled\n"); kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 579ce34e790..1d5a7f41879 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -87,6 +87,11 @@ EXPORT_SYMBOL_GPL(kvm_x86_ops); int ignore_msrs = 0; module_param_named(ignore_msrs, ignore_msrs, bool, S_IRUGO | S_IWUSR); +bool kvm_has_tsc_control; +EXPORT_SYMBOL_GPL(kvm_has_tsc_control); +u32 kvm_max_guest_tsc_khz; +EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz); + #define KVM_NR_SHARED_MSRS 16 struct kvm_shared_msrs_global { @@ -1986,6 +1991,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_X86_ROBUST_SINGLESTEP: case KVM_CAP_XSAVE: case KVM_CAP_ASYNC_PF: + case KVM_CAP_GET_TSC_KHZ: r = 1; break; case KVM_CAP_COALESCED_MMIO: @@ -2012,6 +2018,9 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_XCRS: r = cpu_has_xsave; break; + case KVM_CAP_TSC_CONTROL: + r = kvm_has_tsc_control; + break; default: r = 0; break; @@ -3045,6 +3054,32 @@ long kvm_arch_vcpu_ioctl(struct file *filp, r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, u.xcrs); break; } + case KVM_SET_TSC_KHZ: { + u32 user_tsc_khz; + + r = -EINVAL; + if (!kvm_has_tsc_control) + break; + + user_tsc_khz = (u32)arg; + + if (user_tsc_khz >= kvm_max_guest_tsc_khz) + goto out; + + kvm_x86_ops->set_tsc_khz(vcpu, user_tsc_khz); + + r = 0; + goto out; + } + case KVM_GET_TSC_KHZ: { + r = -EIO; + if (check_tsc_unstable()) + goto out; + + r = vcpu_tsc_khz(vcpu); + + goto out; + } default: r = -EINVAL; } |