kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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

  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1454944711-33022-4-git-send-email-pbonzini@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mtosatti@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).