From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Haozhong Zhang <haozhong.zhang@intel.com>
Cc: kvm@vger.kernel.org, "Gleb Natapov" <gleb@kernel.org>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, "Joerg Roedel" <joro@8bytes.org>,
"Wanpeng Li" <wanpeng.li@linux.intel.com>,
"Xiao Guangrong" <guangrong.xiao@linux.intel.com>,
"Mihai Donțu" <mdontu@bitdefender.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Kai Huang" <kai.huang@linux.intel.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/12] KVM: x86: Use the correct vcpu's TSC rate to compute time scale
Date: Mon, 5 Oct 2015 22:12:34 +0200 [thread overview]
Message-ID: <20151005201233.GA31314@potion.brq.redhat.com> (raw)
In-Reply-To: <1443418691-24050-9-git-send-email-haozhong.zhang@intel.com>
2015-09-28 13:38+0800, Haozhong Zhang:
> This patch makes KVM use virtual_tsc_khz rather than the host TSC rate
> as vcpu's TSC rate to compute the time scale if TSC scaling is enabled.
>
> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
> ---
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> @@ -1782,7 +1782,9 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
> return 0;
>
> if (unlikely(vcpu->hw_tsc_khz != this_tsc_khz)) {
> - kvm_get_time_scale(NSEC_PER_SEC / 1000, this_tsc_khz,
> + tgt_tsc_khz = kvm_has_tsc_control ?
> + vcpu->virtual_tsc_khz : this_tsc_khz;
> + kvm_get_time_scale(NSEC_PER_SEC / 1000, tgt_tsc_khz,
> &vcpu->hv_clock.tsc_shift,
> &vcpu->hv_clock.tsc_to_system_mul);
Good catch, it seems that SVM didn't scale kvmclock correctly ...
I think we'll want this patch in stable.
next prev parent reply other threads:[~2015-10-05 20:12 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-28 5:37 [PATCH 00/12] KVM: x86: add support for VMX TSC scaling Haozhong Zhang
2015-09-28 5:38 ` [PATCH 01/12] KVM: x86: Collect information for setting TSC scaling ratio Haozhong Zhang
2015-09-29 3:28 ` Eric Northup
2015-09-29 4:01 ` Haozhong Zhang
2015-09-28 5:38 ` [PATCH 02/12] KVM: x86: Add a common TSC scaling ratio field in kvm_vcpu_arch Haozhong Zhang
2015-10-05 19:26 ` Radim Krčmář
2015-10-06 1:54 ` Haozhong Zhang
2015-09-28 5:38 ` [PATCH 03/12] KVM: x86: Add a common TSC scaling function Haozhong Zhang
2015-09-28 20:12 ` Paolo Bonzini
2015-09-29 1:51 ` Haozhong Zhang
2015-09-28 5:38 ` [PATCH 04/12] KVM: x86: Replace call-back set_tsc_khz() with a common function Haozhong Zhang
[not found] ` <CAG7+5M3z2-OKsy0wxxks2oW9+7WmFpO4JQETTx3KsaW-hWMGqw@mail.gmail.com>
2015-09-29 3:47 ` Haozhong Zhang
2015-10-05 19:53 ` Radim Krčmář
2015-10-05 20:46 ` David Matlack
2015-10-06 4:06 ` Haozhong Zhang
2015-10-06 10:40 ` Paolo Bonzini
2015-10-06 11:32 ` Haozhong Zhang
2015-09-28 5:38 ` [PATCH 05/12] KVM: x86: Replace call-back compute_tsc_offset() " Haozhong Zhang
2015-09-28 5:38 ` [PATCH 06/12] KVM: x86: Move TSC scaling logic out of call-back adjust_tsc_offset() Haozhong Zhang
2015-09-28 20:14 ` Paolo Bonzini
2015-09-29 1:47 ` Haozhong Zhang
2015-09-28 5:38 ` [PATCH 07/12] KVM: x86: Move TSC scaling logic out of call-back read_l1_tsc() Haozhong Zhang
2015-09-28 5:38 ` [PATCH 08/12] KVM: x86: Use the correct vcpu's TSC rate to compute time scale Haozhong Zhang
2015-10-05 20:12 ` Radim Krčmář [this message]
2015-09-28 5:38 ` [PATCH 09/12] KVM: VMX: Enable and initialize VMX TSC scaling Haozhong Zhang
2015-09-28 5:38 ` [PATCH 10/12] KVM: VMX: Setup TSC scaling ratio when a vcpu is loaded Haozhong Zhang
2015-09-28 5:38 ` [PATCH 11/12] KVM: VMX: Use a scaled host TSC for guest readings of MSR_IA32_TSC Haozhong Zhang
2015-09-28 5:38 ` [PATCH 12/12] KVM: VMX: Dump TSC multiplier in dump_vmcs() Haozhong Zhang
2015-09-29 4:00 ` [PATCH 00/12] KVM: x86: add support for VMX TSC scaling Eric Northup
2015-09-29 4:03 ` Haozhong Zhang
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