This patch implements a common function hvm_scale_tsc() to scale TSC by using TSC scaling information collected by architecture code.
Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com> --- xen/arch/x86/hvm/hvm.c | 18 +++++++++-- xen/arch/x86/hvm/svm/svm.c | 12 -------- xen/arch/x86/time.c | 2 +- xen/include/asm-x86/hvm/hvm.h | 3 +- xen/include/asm-x86/math64.h | 70 +++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 88 insertions(+), 17 deletions(-) diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c index 52a0ef8..1e3d89f 100644 --- a/xen/arch/x86/hvm/hvm.c +++ b/xen/arch/x86/hvm/hvm.c @@ -302,6 +302,20 @@ int hvm_set_guest_pat(struct vcpu *v, u64 guest_pat) return 1; } +u64 hvm_scale_tsc(const struct vcpu *v, u64 tsc) +{ + u64 ratio = v->arch.hvm_vcpu.tsc_scaling_ratio; + + if ( !hvm_funcs.tsc_scaling_supported || + ratio == hvm_funcs.default_tsc_scaling_ratio ) + return tsc; + + BUG_ON(hvm_funcs.tsc_scaling_ratio_frac_bits >= 64 || + hvm_funcs.tsc_scaling_ratio_frac_bits == 0); + + return mul_u64_u64_shr(tsc, ratio, hvm_funcs.tsc_scaling_ratio_frac_bits); +} + void hvm_setup_tsc_scaling(struct vcpu *v) { u64 ratio; @@ -339,7 +353,7 @@ void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc) { tsc = at_tsc ?: rdtsc(); if ( cpu_has_tsc_ratio ) - tsc = hvm_funcs.scale_tsc(v, tsc); + tsc = hvm_scale_tsc(v, tsc); } delta_tsc = guest_tsc - tsc; @@ -371,7 +385,7 @@ u64 hvm_get_guest_tsc_fixed(struct vcpu *v, uint64_t at_tsc) { tsc = at_tsc ?: rdtsc(); if ( cpu_has_tsc_ratio ) - tsc = hvm_funcs.scale_tsc(v, tsc); + tsc = hvm_scale_tsc(v, tsc); } return tsc + v->arch.hvm_vcpu.cache_tsc_offset; diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c index d291327..9e28245 100644 --- a/xen/arch/x86/hvm/svm/svm.c +++ b/xen/arch/x86/hvm/svm/svm.c @@ -804,16 +804,6 @@ static uint64_t scale_tsc(uint64_t host_tsc, uint64_t ratio) return scaled_host_tsc; } -static uint64_t svm_scale_tsc(struct vcpu *v, uint64_t tsc) -{ - struct domain *d = v->domain; - - if ( !cpu_has_tsc_ratio || d->arch.vtsc ) - return tsc; - - return scale_tsc(tsc, v->arch.hvm_vcpu.tsc_scaling_ratio); -} - static uint64_t svm_get_tsc_offset(uint64_t host_tsc, uint64_t guest_tsc, uint64_t ratio) { @@ -2275,8 +2265,6 @@ static struct hvm_function_table __initdata svm_function_table = { .nhvm_intr_blocked = nsvm_intr_blocked, .nhvm_hap_walk_L1_p2m = nsvm_hap_walk_L1_p2m, - .scale_tsc = svm_scale_tsc, - .default_tsc_scaling_ratio = DEFAULT_TSC_RATIO, .max_tsc_scaling_ratio = ~TSC_RATIO_RSVD_BITS, .tsc_scaling_ratio_frac_bits = 32, diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c index d4a94eb..2277158 100644 --- a/xen/arch/x86/time.c +++ b/xen/arch/x86/time.c @@ -817,7 +817,7 @@ static void __update_vcpu_system_time(struct vcpu *v, int force) { if ( is_hvm_domain(d) && cpu_has_tsc_ratio ) { - tsc_stamp = hvm_funcs.scale_tsc(v, t->local_tsc_stamp); + tsc_stamp = hvm_scale_tsc(v, t->local_tsc_stamp); _u.tsc_to_system_mul = d->arch.vtsc_to_ns.mul_frac; _u.tsc_shift = d->arch.vtsc_to_ns.shift; } diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h index e74524e..8fc59d5 100644 --- a/xen/include/asm-x86/hvm/hvm.h +++ b/xen/include/asm-x86/hvm/hvm.h @@ -225,8 +225,6 @@ struct hvm_function_table { bool_t (*altp2m_vcpu_emulate_ve)(struct vcpu *v); int (*altp2m_vcpu_emulate_vmfunc)(struct cpu_user_regs *regs); - uint64_t (*scale_tsc)(struct vcpu *v, uint64_t tsc); - /* Architecture function to setup TSC scaling ratio */ void (*setup_tsc_scaling)(struct vcpu *v); }; @@ -264,6 +262,7 @@ void hvm_set_guest_tsc_fixed(struct vcpu *v, u64 guest_tsc, u64 at_tsc); u64 hvm_get_guest_tsc_fixed(struct vcpu *v, u64 at_tsc); #define hvm_get_guest_tsc(v) hvm_get_guest_tsc_fixed(v, 0) +u64 hvm_scale_tsc(const struct vcpu *v, u64 tsc); void hvm_setup_tsc_scaling(struct vcpu *v); int hvm_set_mode(struct vcpu *v, int mode); diff --git a/xen/include/asm-x86/math64.h b/xen/include/asm-x86/math64.h index 9af6aee..c6a472b 100644 --- a/xen/include/asm-x86/math64.h +++ b/xen/include/asm-x86/math64.h @@ -27,4 +27,74 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) return rl.ll; } +/* + * Multiply two 64-bit unsigned integers a and b. The most and least + * significant 64 bits of the 128-bit result are returned through hi + * and lo respectively. + */ +static inline void mul64(u64 *lo, u64 *hi, u64 a, u64 b) +{ + typedef union { + u64 ll; + struct { + u32 low, high; + } l; + } LL; + LL rl, rm, rn, rh, a0, b0; + u64 c; + + a0.ll = a; + b0.ll = b; + + rl.ll = (u64)a0.l.low * b0.l.low; + rm.ll = (u64)a0.l.low * b0.l.high; + rn.ll = (u64)a0.l.high * b0.l.low; + rh.ll = (u64)a0.l.high * b0.l.high; + + c = (u64)rl.l.high + rm.l.low + rn.l.low; + rl.l.high = c; + c >>= 32; + c = c + rm.l.high + rn.l.high + rh.l.low; + rh.l.low = c; + rh.l.high += (u32)(c >> 32); + + *lo = rl.ll; + *hi = rh.ll; +} + +/* + * Right shift a 128-bit unsigned integer by n bits. The most and + * least significant 64 bits of the 128-bit integer are passed through + * hi and lo respectively. The most and least significant 64 bits of + * the result are also returned through hi and lo respectively. + */ +static inline void rshift128(u64 *lo, u64 *hi, unsigned int n) +{ + u64 h; + if ( !n ) + return; + h = *hi >> (n & 63); + if ( n >= 64 ) + { + *hi = 0; + *lo = h; + } + else + { + *lo = (*lo >> n) | (*hi << (64 - n)); + *hi = h; + } +} + +/* + * (a * mul) >> n + */ +static inline u64 mul_u64_u64_shr(u64 a, u64 mul, unsigned int n) +{ + u64 lo, hi; + mul64(&lo, &hi, a, mul); + rshift128(&lo, &hi, n); + return lo; +} + #endif -- 2.6.3 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel