From: Avi Kivity <avi@redhat.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Yang, Wei Y" <wei.y.yang@intel.com>,
Pekka Enberg <penberg@cs.helsinki.fi>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS
Date: Mon, 30 May 2011 11:53:58 +0300 [thread overview]
Message-ID: <4DE35B26.2000403@redhat.com> (raw)
In-Reply-To: <20110530085232.GL30513@elte.hu>
On 05/30/2011 11:52 AM, Ingo Molnar wrote:
> * Avi Kivity<avi@redhat.com> wrote:
>
> > > Another option would be to try to set the SMEP bit *before* we
> > > enable paging. In theory this should not confuse a Linux guest -
> > > and while i have not tested it i *think* we let it survive in the
> > > saved_cr4_features shadow variable. That would make guest
> > > suspend/resume work out of box as well.
> >
> > Is there any reason not to do it in a hidden way in kvm? Why must
> > we play tricks?
>
> So do you have a suggestion of how to do this cleaner?
>
> Add an ioctl that allows a VCPU to be configured in a way to set a
> cr4 feature without the guest actually seeing that bit? [Assuming
> both cr4 reads and writes are fully captured by KVM and thus guest
> behavior is controllable.]
Yes, this was what I suggested before. IIRC you liked it.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-05-30 8:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-30 3:01 [Patch v5 1/4] Remove SMEP bit from CR4_RESERVED_BITS Yang, Wei Y
2011-05-30 7:40 ` Ingo Molnar
2011-05-30 7:49 ` Avi Kivity
2011-05-30 8:05 ` Ingo Molnar
2011-05-30 8:43 ` Avi Kivity
2011-05-30 8:52 ` Ingo Molnar
2011-05-30 8:53 ` Avi Kivity [this message]
2011-05-30 8:57 ` Ingo Molnar
2011-05-30 9:00 ` Avi Kivity
2011-06-01 7:18 ` Tian, Kevin
2011-06-01 7:46 ` Ingo Molnar
2011-06-01 7:55 ` Avi Kivity
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