From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: qemu-devel@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Richard Henderson <rth@twiddle.net>,
	Eduardo Habkost <ehabkost@redhat.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Roman Kagan <rkagan@virtuozzo.com>
Subject: Re: [Qemu-devel] [PATCH v5 0/1] i386/kvm: TSC page clocksource for Hyper-V-on-KVM fixes
Date: Wed, 02 May 2018 09:34:19 +0200	[thread overview]
Message-ID: <877eomtssk.fsf@vitty.brq.redhat.com> (raw)
In-Reply-To: <20180411115036.31832-1-vkuznets@redhat.com> (Vitaly Kuznetsov's message of "Wed, 11 Apr 2018 13:50:35 +0200")
Vitaly Kuznetsov <vkuznets@redhat.com> writes:
> Changes since v4:
> - Rebase on top of Roman's patches.
> - Drop PATCH2 as it is no longer needed (after adding explicit
>   hv_frequencies).
>
> Previously, Ladi was working on enabling TSC page clocksource for nested
> Hyper-V-on-KVM workloads. He found out that if Hyper-V frequency MSRs are
> exposed to L1 as well as INVTSC flag Hyper-V enables TSC page clocksource
> to its guests. Qemu doesn't pass INVTSC by default as it is a migration
> blocker.
>
> I found out there's a different way to make Hyper-V like us: expose
> Reenlightenment MSRs to it. KVM doesn't fully support the feature as
> we're still unable to migrate nested environments but rudimentary support
> we have there is enough.
>
> Enable Hyper-V reenlightenment MSRs to make things work.
>
Gentle ping :-)
With Roman's Reviewed-by:, is there anything else needed from me to get
this accepted?
Thanks!
-- 
  Vitaly
next prev parent reply	other threads:[~2018-05-02  7:34 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11 11:50 [Qemu-devel] [PATCH v5 0/1] i386/kvm: TSC page clocksource for Hyper-V-on-KVM fixes Vitaly Kuznetsov
2018-04-11 11:50 ` [Qemu-devel] [PATCH v5 1/1] i386/kvm: add support for Hyper-V reenlightenment MSRs Vitaly Kuznetsov
2018-04-11 12:01   ` Roman Kagan
2018-05-02  7:34 ` Vitaly Kuznetsov [this message]
2018-05-07 16:57   ` [Qemu-devel] [PATCH v5 0/1] i386/kvm: TSC page clocksource for Hyper-V-on-KVM fixes Paolo Bonzini
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