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From: Marcelo Tosatti <mtosatti@redhat.com>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: libvir-list@redhat.com, Paolo Bonzini <pbonzini@redhat.com>,
	qemu-devel@nongnu.org, kvm@vger.kernel.org,
	Haozhong Zhang <haozhong.zhang@intel.com>
Subject: Re: TSC frequency configuration & invtsc migration (was Re: [PATCH 4/4] kvm: Allow migration with invtsc)
Date: Thu, 5 Jan 2017 08:50:48 -0200	[thread overview]
Message-ID: <20170105105046.GC6299@amt.cnet> (raw)
In-Reply-To: <20170105104830.GB6299@amt.cnet>

On Thu, Jan 05, 2017 at 08:48:32AM -0200, Marcelo Tosatti wrote:
> > Note that even if we follow your suggestion and implement an
> > alternative version of patch 4/4 to cover your use case, I will
> > strongly recommend libvirt developers to support configuring TSC
> > frequency if they want to support invtsc + migration without
> > surprising/unpredictable restrictions on migratability.
> 
> Well, alright. If you make the TSC frequency of the host
> available to mgmt software as you describe, and write the steps mgmt
> software should take, i'm good.
> 
> Thanks for the help Eduardo.
> 

I'll be happy to not have to add a weird script to 

1. Query the host TSC frequency.
2. Pass that to -cpu xxx,tsc-frequency=ZZZ

To my migration scripts. 

Probably easy to make that the default behaviour...

WARNING: multiple messages have this Message-ID (diff)
From: Marcelo Tosatti <mtosatti@redhat.com>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: qemu-devel@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>,
	kvm@vger.kernel.org, Haozhong Zhang <haozhong.zhang@intel.com>,
	libvir-list@redhat.com
Subject: Re: [Qemu-devel] TSC frequency configuration & invtsc migration (was Re: [PATCH 4/4] kvm: Allow migration with invtsc)
Date: Thu, 5 Jan 2017 08:50:48 -0200	[thread overview]
Message-ID: <20170105105046.GC6299@amt.cnet> (raw)
In-Reply-To: <20170105104830.GB6299@amt.cnet>

On Thu, Jan 05, 2017 at 08:48:32AM -0200, Marcelo Tosatti wrote:
> > Note that even if we follow your suggestion and implement an
> > alternative version of patch 4/4 to cover your use case, I will
> > strongly recommend libvirt developers to support configuring TSC
> > frequency if they want to support invtsc + migration without
> > surprising/unpredictable restrictions on migratability.
> 
> Well, alright. If you make the TSC frequency of the host
> available to mgmt software as you describe, and write the steps mgmt
> software should take, i'm good.
> 
> Thanks for the help Eduardo.
> 

I'll be happy to not have to add a weird script to 

1. Query the host TSC frequency.
2. Pass that to -cpu xxx,tsc-frequency=ZZZ

To my migration scripts. 

Probably easy to make that the default behaviour...

  reply	other threads:[~2017-01-05 10:50 UTC|newest]

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-27 19:21 [PATCH 0/4] Allow migration with invtsc if there's no frequency mismatch Eduardo Habkost
2016-12-27 19:21 ` [Qemu-devel] " Eduardo Habkost
2016-12-27 19:21 ` [PATCH 1/4] kvm: Simplify invtsc check Eduardo Habkost
2016-12-27 19:21   ` [Qemu-devel] " Eduardo Habkost
2016-12-29 18:57   ` Marcelo Tosatti
2016-12-29 18:57     ` [Qemu-devel] " Marcelo Tosatti
2016-12-27 19:21 ` [PATCH 2/4] kvm: Allow invtsc migration if tsc-khz is set explicitly Eduardo Habkost
2016-12-27 19:21   ` [Qemu-devel] " Eduardo Habkost
2017-01-04 11:44   ` Marcelo Tosatti
2017-01-04 11:44     ` [Qemu-devel] " Marcelo Tosatti
2017-01-04 11:57     ` Marcelo Tosatti
2017-01-04 11:57       ` [Qemu-devel] " Marcelo Tosatti
2017-01-04 13:40     ` Eduardo Habkost
2017-01-04 13:40       ` [Qemu-devel] " Eduardo Habkost
2017-01-04 13:45       ` Marcelo Tosatti
2017-01-04 13:45         ` [Qemu-devel] " Marcelo Tosatti
2017-01-04 13:51         ` Eduardo Habkost
2017-01-04 13:51           ` [Qemu-devel] " Eduardo Habkost
2016-12-27 19:21 ` [PATCH 3/4] pc: Add 2.9 machine-types Eduardo Habkost
2016-12-27 19:21   ` [Qemu-devel] " Eduardo Habkost
2016-12-30 13:38   ` Igor Mammedov
2016-12-30 13:38     ` [Qemu-devel] " Igor Mammedov
2017-01-04 14:01   ` Laszlo Ersek
2017-01-04 14:20     ` Eduardo Habkost
2017-01-04 14:20       ` [Qemu-devel] " Eduardo Habkost
2017-01-04 16:40       ` Laszlo Ersek
2017-01-04 16:40         ` [Qemu-devel] " Laszlo Ersek
2017-01-04 17:46         ` Eduardo Habkost
2016-12-27 19:21 ` [PATCH 4/4] kvm: Allow migration with invtsc Eduardo Habkost
2016-12-27 19:21   ` [Qemu-devel] " Eduardo Habkost
2017-01-04 11:56   ` Marcelo Tosatti
2017-01-04 11:56     ` [Qemu-devel] " Marcelo Tosatti
2017-01-04 13:39     ` Eduardo Habkost
2017-01-04 13:39       ` [Qemu-devel] " Eduardo Habkost
2017-01-04 19:59       ` [libvirt] TSC frequency configuration & invtsc migration (was Re: [PATCH 4/4] kvm: Allow migration with invtsc) Eduardo Habkost
2017-01-04 19:59         ` [Qemu-devel] " Eduardo Habkost
2017-01-04 22:26         ` Marcelo Tosatti
2017-01-04 22:26           ` [Qemu-devel] " Marcelo Tosatti
2017-01-05  1:36           ` Eduardo Habkost
2017-01-05  1:36             ` [Qemu-devel] " Eduardo Habkost
2017-01-05 10:48             ` Marcelo Tosatti
2017-01-05 10:48               ` [Qemu-devel] " Marcelo Tosatti
2017-01-05 10:50               ` Marcelo Tosatti [this message]
2017-01-05 10:50                 ` Marcelo Tosatti
2017-01-05 12:19               ` Eduardo Habkost
2017-01-05 12:19                 ` [Qemu-devel] " Eduardo Habkost
2017-01-05 12:33                 ` [libvirt] " Daniel P. Berrange
2017-01-05 12:33                   ` [Qemu-devel] " Daniel P. Berrange
2017-01-05 12:48                   ` Eduardo Habkost
2017-01-05 12:48                     ` [Qemu-devel] " Eduardo Habkost
2017-01-05 13:00                     ` Daniel P. Berrange
2017-01-05 13:00                       ` [Qemu-devel] " Daniel P. Berrange
2017-01-05 13:11                       ` Eduardo Habkost
2017-01-05 13:11                         ` [Qemu-devel] " Eduardo Habkost
2017-01-10 16:38                       ` Paolo Bonzini
2017-01-10 16:38                         ` [Qemu-devel] " Paolo Bonzini
2017-01-06 10:31                 ` Marcelo Tosatti
2017-01-06 10:31                   ` [Qemu-devel] " Marcelo Tosatti
2017-01-08 15:49                   ` How to make dest host abort migration safely " Eduardo Habkost
2017-01-08 15:49                     ` [Qemu-devel] " Eduardo Habkost
2017-01-09 10:04                     ` [libvirt] " Dr. David Alan Gilbert
2017-01-09 10:04                       ` [Qemu-devel] " Dr. David Alan Gilbert
2017-01-08 20:28                   ` Exporting kvm_max_guest_tsc_khz to userspace " Eduardo Habkost
2017-01-08 20:28                     ` [Qemu-devel] " Eduardo Habkost
2017-01-09 14:58                     ` Paolo Bonzini
2017-01-09 14:58                       ` [Qemu-devel] " Paolo Bonzini
2017-01-11 13:26                       ` Eduardo Habkost
2017-01-11 13:26                         ` [Qemu-devel] " Eduardo Habkost
2017-01-11 14:06                         ` Paolo Bonzini
2017-01-11 14:06                           ` [Qemu-devel] " Paolo Bonzini
2017-01-10 16:36               ` TSC frequency configuration & invtsc migration " Paolo Bonzini
2017-01-10 16:36                 ` [Qemu-devel] " Paolo Bonzini
2017-01-11 11:58                 ` Eduardo Habkost
2017-01-11 11:58                   ` [Qemu-devel] " Eduardo Habkost
2017-01-18 11:55                 ` Marcelo Tosatti
2017-01-18 11:55                   ` [Qemu-devel] " Marcelo Tosatti
2017-01-18 12:43                   ` Eduardo Habkost
2017-01-18 12:43                     ` [Qemu-devel] " Eduardo Habkost

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