This patch implements two new vm-ioctls to get and set the virtual_tsc_khz if the machine supports tsc-scaling. Setting the tsc-frequency is only possible before userspace creates any vcpu.
Signed-off-by: Joerg Roedel <[email protected]> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/svm.c | 3 +++ arch/x86/kvm/x86.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/kvm.h | 4 ++++ 4 files changed, 46 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8c40425..dfdd0aa 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -633,6 +633,7 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn); extern bool tdp_enabled; +extern int kvm_has_tsc_control; enum emulation_result { EMULATE_DONE, /* no further processing */ diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index f938585..0b8f4f7 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -797,6 +797,9 @@ 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)) + kvm_has_tsc_control = 1; + 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 6caaf4b..1ac94cc 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -99,6 +99,9 @@ EXPORT_SYMBOL_GPL(kvm_x86_ops); int ignore_msrs = 0; module_param_named(ignore_msrs, ignore_msrs, bool, S_IRUGO | S_IWUSR); +int kvm_has_tsc_control; +EXPORT_SYMBOL_GPL(kvm_has_tsc_control); + #define KVM_NR_SHARED_MSRS 16 struct kvm_shared_msrs_global { @@ -2024,6 +2027,9 @@ 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; @@ -3575,6 +3581,38 @@ long kvm_arch_vm_ioctl(struct file *filp, r = 0; break; } + case KVM_SET_TSC_KHZ: { + u32 user_tsc_khz; + + if (!kvm_has_tsc_control) + break; + + /* + * We force the tsc frequency to be set before any + * vcpu is created + */ + if (atomic_read(&kvm->online_vcpus) > 0) + goto out; + + user_tsc_khz = arg; + + kvm_arch_set_tsc_khz(kvm, user_tsc_khz); + + r = 0; + goto out; + } + case KVM_GET_TSC_KHZ: { + + if (!kvm_has_tsc_control) + break; + + r = -EFAULT; + if (copy_to_user(argp, &kvm->arch.virtual_tsc_khz, sizeof(__u32))) + goto out; + + r = 0; + goto out; + } default: ; diff --git a/include/linux/kvm.h b/include/linux/kvm.h index ea2dc1a..a96ff92 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -541,6 +541,7 @@ struct kvm_ppc_pvinfo { #define KVM_CAP_PPC_GET_PVINFO 57 #define KVM_CAP_PPC_IRQ_LEVEL 58 #define KVM_CAP_ASYNC_PF 59 +#define KVM_CAP_TSC_CONTROL 60 #ifdef KVM_CAP_IRQ_ROUTING @@ -677,6 +678,9 @@ struct kvm_clock_data { #define KVM_SET_PIT2 _IOW(KVMIO, 0xa0, struct kvm_pit_state2) /* Available with KVM_CAP_PPC_GET_PVINFO */ #define KVM_PPC_GET_PVINFO _IOW(KVMIO, 0xa1, struct kvm_ppc_pvinfo) +/* Available with KVM_CAP_TSC_CONTROL */ +#define KVM_SET_TSC_KHZ _IOW(KVMIO, 0xa2, __u32) +#define KVM_GET_TSC_KHZ _IOR(KVMIO, 0xa3, __u32) /* * ioctls for vcpu fds -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
