diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm.c | 36 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx.c | 17 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 46 | ||||
| -rw-r--r-- | include/linux/math64.h | 29 |
5 files changed, 70 insertions, 59 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 52d1419968eb..c5a3f3d66e90 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -853,7 +853,6 @@ struct kvm_x86_ops { bool (*has_wbinvd_exit)(void); - void (*set_tsc_khz)(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale); u64 (*read_tsc_offset)(struct kvm_vcpu *vcpu); void (*write_tsc_offset)(struct kvm_vcpu *vcpu, u64 offset); diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 65f4f1947a62..f6e49a6c9ab0 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -957,41 +957,6 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type) seg->base = 0; } -static void svm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale) -{ - u64 ratio; - u64 khz; - - /* Guest TSC same frequency as host TSC? */ - if (!scale) { - vcpu->arch.tsc_scaling_ratio = TSC_RATIO_DEFAULT; - return; - } - - /* TSC scaling supported? */ - if (!boot_cpu_has(X86_FEATURE_TSCRATEMSR)) { - if (user_tsc_khz > tsc_khz) { - vcpu->arch.tsc_catchup = 1; - vcpu->arch.tsc_always_catchup = 1; - } else - WARN(1, "user requested TSC rate below hardware speed\n"); - return; - } - - khz = user_tsc_khz; - - /* TSC scaling required - calculate ratio */ - ratio = khz << 32; - do_div(ratio, tsc_khz); - - if (ratio == 0 || ratio & TSC_RATIO_RSVD) { - WARN_ONCE(1, "Invalid TSC ratio - virtual-tsc-khz=%u\n", - user_tsc_khz); - return; - } - vcpu->arch.tsc_scaling_ratio = ratio; -} - static u64 svm_read_tsc_offset(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); @@ -4402,7 +4367,6 @@ static struct kvm_x86_ops svm_x86_ops = { .has_wbinvd_exit = svm_has_wbinvd_exit, - .set_tsc_khz = svm_set_tsc_khz, .read_tsc_offset = svm_read_tsc_offset, .write_tsc_offset = svm_write_tsc_offset, .adjust_tsc_offset = svm_adjust_tsc_offset, diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index a26ed285931b..baee46893899 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2382,22 +2382,6 @@ static u64 vmx_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc) return host_tsc + tsc_offset; } -/* - * Engage any workarounds for mis-matched TSC rates. Currently limited to - * software catchup for faster rates on slower CPUs. - */ -static void vmx_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale) -{ - if (!scale) - return; - - if (user_tsc_khz > tsc_khz) { - vcpu->arch.tsc_catchup = 1; - vcpu->arch.tsc_always_catchup = 1; - } else - WARN(1, "user requested TSC rate below hardware speed\n"); -} - static u64 vmx_read_tsc_offset(struct kvm_vcpu *vcpu) { return vmcs_read64(TSC_OFFSET); @@ -10826,7 +10810,6 @@ static struct kvm_x86_ops vmx_x86_ops = { .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit, - .set_tsc_khz = vmx_set_tsc_khz, .read_tsc_offset = vmx_read_tsc_offset, .write_tsc_offset = vmx_write_tsc_offset, .adjust_tsc_offset = vmx_adjust_tsc_offset, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 1473e64cb744..c314e8d22a67 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1253,7 +1253,43 @@ static u32 adjust_tsc_khz(u32 khz, s32 ppm) return v; } -static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) +static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale) +{ + u64 ratio; + + /* Guest TSC same frequency as host TSC? */ + if (!scale) { + vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; + return 0; + } + + /* TSC scaling supported? */ + if (!kvm_has_tsc_control) { + if (user_tsc_khz > tsc_khz) { + vcpu->arch.tsc_catchup = 1; + vcpu->arch.tsc_always_catchup = 1; + return 0; + } else { + WARN(1, "user requested TSC rate below hardware speed\n"); + return -1; + } + } + + /* TSC scaling required - calculate ratio */ + ratio = mul_u64_u32_div(1ULL << kvm_tsc_scaling_ratio_frac_bits, + user_tsc_khz, tsc_khz); + + if (ratio == 0 || ratio >= kvm_max_tsc_scaling_ratio) { + WARN_ONCE(1, "Invalid TSC scaling ratio - virtual-tsc-khz=%u\n", + user_tsc_khz); + return -1; + } + + vcpu->arch.tsc_scaling_ratio = ratio; + return 0; +} + +static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) { u32 thresh_lo, thresh_hi; int use_scaling = 0; @@ -1262,7 +1298,7 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) if (this_tsc_khz == 0) { /* set tsc_scaling_ratio to a safe value */ vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio; - return; + return -1; } /* Compute a scale to convert nanoseconds in TSC cycles */ @@ -1283,7 +1319,7 @@ static void kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 this_tsc_khz) pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", this_tsc_khz, thresh_lo, thresh_hi); use_scaling = 1; } - kvm_x86_ops->set_tsc_khz(vcpu, this_tsc_khz, use_scaling); + return set_tsc_khz(vcpu, this_tsc_khz, use_scaling); } static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns) @@ -3353,9 +3389,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp, if (user_tsc_khz == 0) user_tsc_khz = tsc_khz; - kvm_set_tsc_khz(vcpu, user_tsc_khz); + if (!kvm_set_tsc_khz(vcpu, user_tsc_khz)) + r = 0; - r = 0; goto out; } case KVM_GET_TSC_KHZ: { diff --git a/include/linux/math64.h b/include/linux/math64.h index 44282ec7b682..6e8b5b270ffe 100644 --- a/include/linux/math64.h +++ b/include/linux/math64.h @@ -214,4 +214,33 @@ static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift) #endif +#ifndef mul_u64_u32_div +static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) +{ + union { + u64 ll; + struct { +#ifdef __BIG_ENDIAN + u32 high, low; +#else + u32 low, high; +#endif + } l; + } u, rl, rh; + + u.ll = a; + rl.ll = (u64)u.l.low * mul; + rh.ll = (u64)u.l.high * mul + rl.l.high; + + /* Bits 32-63 of the result will be in rh.l.low. */ + rl.l.high = do_div(rh.ll, divisor); + + /* Bits 0-31 of the result will be in rl.l.low. */ + do_div(rl.ll, divisor); + + rl.l.high = rh.l.low; + return rl.ll; +} +#endif /* mul_u64_u32_div */ + #endif /* _LINUX_MATH64_H */ |