linux-kernel - Re: [PATCH v2 0/7] x86/kvm/hyperv: stable clocksorce for L2 guests when running nested KVM on Hyper-V

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 15 Dec 2017 10:30:54 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     Paolo Bonzini <pbonzini@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>
Cc:     kvm@...r.kernel.org, x86@...nel.org,
        Radim Krčmář <rkrcmar@...hat.com>,
        "K. Y. Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        "Michael Kelley \(EOSG\)" <Michael.H.Kelley@...rosoft.com>,
        Andy Lutomirski <luto@...nel.org>,
        Mohammed Gamal <mmorsy@...hat.com>,
        Cathy Avery <cavery@...hat.com>,
        Roman Kagan <rkagan@...tuozzo.com>,
        linux-kernel@...r.kernel.org, devel@...uxdriverproject.org
Subject: Re: [PATCH v2 0/7] x86/kvm/hyperv: stable clocksorce for L2 guests when running nested KVM on Hyper-V

Paolo Bonzini <pbonzini@...hat.com> writes:

> On 13/12/2017 16:09, Vitaly Kuznetsov wrote:
>> Currently, KVM passes PVCLOCK_TSC_STABLE_BIT to its guests when running in
>> so called 'masterclock' mode and this is only possible when the clocksource
>> on the host is TSC. When running nested on Hyper-V we're using a different
>> clocksource in L1 (Hyper-V TSC Page) which can actually be used for
>> masterclock. This series brings the required support.
>> 
>> Making KVM work with TSC page clocksource is relatively easy, it is done in
>> PATCH 5 of the series. All the rest is required to support L1 migration
>   ^^^^^^^
>
> Patch 6. :)
>

Off-by-one :-)

>> when TSC frequency changes, we use a special feature from Hyper-V to do
>> the job.
>
> Patches 5-7 are
>
> Acked-by: Paolo Bonzini <pbonzini@...hat.com>
>

Thanks!

> I would appreciate if the Hyper-V folks can provide a topic branch to be
> merged in both HV and KVM trees.
>

There's no such thing as Hyper-V tree, patches are usually getting
merged through 'tip' tree when the majority of changes go to arch/x86 or
Greg's char-misc tree when changes are drivers/hv heavy (+ net, scsi,
pci, hid, ... trees for individual drivers).

In this particular case the series is x86-heavy and I believe it should
go through x86 'tip' tree.

Thomas, Ingo, Peter, could you please take a look? Thanks!

-- 
  Vitaly