From: Paolo Bonzini <pbonzini@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: Arthur Chunqi Li <yzt356@gmail.com>,
kvm@vger.kernel.org, jan.kiszka@web.de
Subject: Re: [PATCH] KVM : Fix read/write to IA32_FEATURE_CONTROL MSR in nested virt
Date: Thu, 04 Jul 2013 13:21:51 +0200 [thread overview]
Message-ID: <51D55ACF.8070702@redhat.com> (raw)
In-Reply-To: <20130704111235.GI5113@redhat.com>
Il 04/07/2013 13:12, Gleb Natapov ha scritto:
> > I don't like that it requires a firmware change in order to use nested
> > VMX (at least for hypervisors that read the MSR). "Worse emulation" and
> > "better emulation + new firmware" are indistiguishable from the point of
> > view of anyone except the firmware.
> >
> > IMO there is no reason for a better emulation that no one would care
> > about _and_ could look like a regression when updating to a newer kernel.
>
> That is why now is the good time to do that since nested vmx is not
> widely used. When it will be widely used the change will be impossible
> to do for reason you age giving. So it is now or never.
I think it is a can of worms. For example, should this be
conditionalized on running under QEMU? Under UEFI, TianoCore should be
doing it, not SeaBIOS. And for CoreBoot, should it be done by CoreBoot
or SeaBIOS? (How do people use KVM together with CoreBoot?)
So I still prefer never... :)
Paolo
next prev parent reply other threads:[~2013-07-04 11:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-03 13:41 [PATCH] KVM : Fix read/write to IA32_FEATURE_CONTROL MSR in nested virt Arthur Chunqi Li
2013-07-04 7:00 ` Paolo Bonzini
2013-07-04 7:10 ` Gleb Natapov
2013-07-04 7:21 ` Arthur Chunqi Li
2013-07-04 7:24 ` Gleb Natapov
2013-07-04 8:16 ` Gmail
2013-07-04 10:43 ` Gleb Natapov
2013-07-04 11:01 ` Paolo Bonzini
2013-07-04 11:12 ` Gleb Natapov
2013-07-04 11:21 ` Paolo Bonzini [this message]
2013-07-04 11:31 ` Gleb Natapov
2013-07-04 12:34 ` Paolo Bonzini
2013-07-04 12:43 ` Gleb Natapov
2013-07-05 3:26 ` Arthur Chunqi Li
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