From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: mtosatti@redhat.com
Subject: [PATCH 3/4] KVM: x86: pass kvm_get_time_scale arguments in hertz
Date: Mon, 8 Feb 2016 16:18:30 +0100 [thread overview]
Message-ID: <1454944711-33022-4-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1454944711-33022-1-git-send-email-pbonzini@redhat.com>
Prepare for improving the precision in the next patch.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/x86.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6db3c219795b..e0bf8f10dc22 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1203,7 +1203,7 @@ static uint32_t div_frac(uint32_t dividend, uint32_t divisor)
return dividend;
}
-static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
+static void kvm_get_time_scale(uint64_t scaled_hz, uint64_t base_hz,
s8 *pshift, u32 *pmultiplier)
{
uint64_t scaled64;
@@ -1211,8 +1211,8 @@ static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
uint64_t tps64;
uint32_t tps32;
- tps64 = base_khz * 1000LL;
- scaled64 = scaled_khz * 1000LL;
+ tps64 = base_hz;
+ scaled64 = scaled_hz;
while (tps64 > scaled64*2 || tps64 & 0xffffffff00000000ULL) {
tps64 >>= 1;
shift--;
@@ -1230,8 +1230,8 @@ static void kvm_get_time_scale(uint32_t scaled_khz, uint32_t base_khz,
*pshift = shift;
*pmultiplier = div_frac(scaled64, tps32);
- pr_debug("%s: base_khz %u => %u, shift %d, mul %u\n",
- __func__, base_khz, scaled_khz, shift, *pmultiplier);
+ pr_debug("%s: base_hz %llu => %llu, shift %d, mul %u\n",
+ __func__, base_hz, scaled_hz, shift, *pmultiplier);
}
#ifdef CONFIG_X86_64
@@ -1303,7 +1303,7 @@ static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz)
}
/* Compute a scale to convert nanoseconds in TSC cycles */
- kvm_get_time_scale(user_tsc_khz, NSEC_PER_SEC / 1000,
+ kvm_get_time_scale(user_tsc_khz * 1000LL, NSEC_PER_SEC,
&vcpu->arch.virtual_tsc_shift,
&vcpu->arch.virtual_tsc_mult);
vcpu->arch.virtual_tsc_khz = user_tsc_khz;
@@ -1779,7 +1779,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
tgt_tsc_khz = kvm_scale_tsc(v, tgt_tsc_khz);
if (unlikely(vcpu->hw_tsc_khz != tgt_tsc_khz)) {
- kvm_get_time_scale(NSEC_PER_SEC / 1000, tgt_tsc_khz,
+ kvm_get_time_scale(NSEC_PER_SEC, tgt_tsc_khz * 1000LL,
&vcpu->hv_clock.tsc_shift,
&vcpu->hv_clock.tsc_to_system_mul);
vcpu->hw_tsc_khz = tgt_tsc_khz;
--
1.8.3.1
next prev parent reply other threads:[~2016-02-08 15:18 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-08 15:18 [PATCH 0/4] kvmclock: improve accuracy Paolo Bonzini
2016-02-08 15:18 ` [PATCH 1/4] KVM: x86: rename argument to kvm_set_tsc_khz Paolo Bonzini
2016-02-11 15:01 ` Marcelo Tosatti
2016-02-08 15:18 ` [PATCH 2/4] KVM: x86: rewrite handling of scaled TSC for kvmclock Paolo Bonzini
2016-02-11 15:23 ` Marcelo Tosatti
2016-02-08 15:18 ` Paolo Bonzini [this message]
2016-02-08 15:18 ` [PATCH 4/4] KVM: x86: track actual TSC frequency from the timekeeper struct Paolo Bonzini
2016-02-09 18:41 ` Owen Hofmann
2016-02-10 13:57 ` Paolo Bonzini
2016-02-16 13:48 ` Marcelo Tosatti
2016-02-16 14:25 ` Marcelo Tosatti
2016-02-16 16:59 ` Paolo Bonzini
2016-02-19 14:12 ` Marcelo Tosatti
2016-02-19 15:53 ` Paolo Bonzini
2016-02-16 14:00 ` [PATCH 0/4] kvmclock: improve accuracy Marcelo Tosatti
-- strict thread matches above, loose matches on Subject: below --
2016-01-28 14:04 [PATCH kvm-unit-tests] KVM: x86: add hyperv clock test case Paolo Bonzini
2016-01-28 14:04 ` Paolo Bonzini
2016-01-28 14:25 ` Andrey Smetanin
2016-01-28 14:50 ` Paolo Bonzini
2016-01-28 15:53 ` Paolo Bonzini
2016-01-28 18:45 ` Roman Kagan
2016-01-28 18:53 ` Roman Kagan
2016-01-28 21:28 ` Paolo Bonzini
2016-01-28 16:22 ` Roman Kagan
2016-02-03 16:37 ` Paolo Bonzini
2016-02-04 9:33 ` Roman Kagan
2016-02-04 10:13 ` Paolo Bonzini
2016-02-04 11:12 ` Roman Kagan
2016-04-21 17:01 ` Roman Kagan
2016-04-22 13:32 ` Roman Kagan
2016-04-22 18:08 ` Paolo Bonzini
2016-04-25 8:47 ` Roman Kagan
2016-04-26 10:34 ` Roman Kagan
2016-05-25 18:33 ` Roman Kagan
2016-05-26 14:47 ` Roman Kagan
2016-05-29 22:34 ` Marcelo Tosatti
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