From: Avi Kivity <avi@redhat.com>
To: "Nadav Har'El" <nyh@math.technion.ac.il>
Cc: kvm@vger.kernel.org, "Roedel, Joerg" <Joerg.Roedel@amd.com>,
owasserm@redhat.com, abelg@il.ibm.com
Subject: Re: [PATCH 01/10] nEPT: Module option
Date: Thu, 10 Nov 2011 17:21:01 +0200 [thread overview]
Message-ID: <4EBBEBDD.5090106@redhat.com> (raw)
In-Reply-To: <20111110151405.GC3327@fermat.math.technion.ac.il>
On 11/10/2011 05:14 PM, Nadav Har'El wrote:
> On Thu, Nov 10, 2011, Avi Kivity wrote about "Re: [PATCH 01/10] nEPT: Module option":
> > > By "this", do you mean without the "nested_ept" option, or without the
> > > hypothetical "EPT on shadow page tables" feature?
> >
> > Er, both. The feature should be controlled on a per-guest basis, not
> > per host.
> >..
> > It's just redundant, since we do need a per-guest control.
>
> I agreed that per-guest control would have been nicer, but since we
> don't have an API for specifying that per guest since EPT is not,
> unfortunately, a CPUID feature, I thought that at least a host-level
> flag would be useful.
>
> Why would it be useful? I agree it isn't the most important option since
> sliced bread, but if, for example, one day we discover a bug with nested
> EPT, L0 can disable it for all L1 guests and basically force them to use
> shadow page tables on EPT.
Or we just fix the bug.
> It was also useful for me to have this option for benchmarking, because
> I can force back the old shadow-on-EPT method with just a single option
> in L0 (instead of needing to give "ept=0" option in L1s).
When we have the per-guest controls, we can tell userspace to tell the
kernel disable guest EPT.
> If you really don't like the existance of this option, I can easily
> remove it of course.
Yes please.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-11-10 15:21 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-10 9:57 [PATCH 0/10] nEPT: Nested EPT support for Nested VMX Nadav Har'El
2011-11-10 9:58 ` [PATCH 01/10] nEPT: Module option Nadav Har'El
2011-11-10 12:23 ` Avi Kivity
2011-11-10 14:21 ` Nadav Har'El
2011-11-10 14:38 ` Avi Kivity
2011-11-10 15:14 ` Nadav Har'El
2011-11-10 15:21 ` Avi Kivity [this message]
2011-11-10 9:58 ` [PATCH 02/10] nEPT: MMU context for nested EPT Nadav Har'El
2011-11-10 10:31 ` Avi Kivity
2011-11-10 12:49 ` Avi Kivity
2011-11-10 14:40 ` Nadav Har'El
2011-11-10 15:19 ` Avi Kivity
2011-11-10 20:05 ` Nadav Har'El
2011-11-12 10:39 ` Avi Kivity
2011-11-12 21:37 ` Nadav Har'El
2011-11-13 9:10 ` Avi Kivity
2011-11-13 11:30 ` Orit Wasserman
2011-11-13 14:32 ` Avi Kivity
2011-11-13 18:26 ` Orit Wasserman
2011-11-14 8:25 ` Avi Kivity
2011-12-08 15:21 ` Nadav Har'El
2011-12-06 12:40 ` Nadav Har'El
2011-12-06 13:07 ` Avi Kivity
2011-11-23 15:06 ` Nadav Har'El
2011-11-23 15:44 ` Nadav Har'El
2011-11-24 13:36 ` Avi Kivity
2011-12-07 9:06 ` Nadav Har'El
2011-12-07 10:10 ` Avi Kivity
2011-11-10 9:59 ` [PATCH 03/10] nEPT: Fix cr3 handling in nested exit and entry Nadav Har'El
2011-11-10 9:59 ` [PATCH 04/10] nEPT: Fix page table format in nested EPT Nadav Har'El
2011-11-10 10:37 ` Avi Kivity
2011-11-10 11:03 ` Nadav Har'El
2011-11-10 12:21 ` Avi Kivity
2011-11-10 12:50 ` Avi Kivity
2011-11-10 13:07 ` Orit Wasserman
2011-11-10 10:00 ` [PATCH 05/10] nEPT: Fix wrong test in kvm_set_cr3 Nadav Har'El
2011-11-10 10:00 ` [PATCH 06/10] nEPT: Some additional comments Nadav Har'El
2011-11-10 10:01 ` [PATCH 07/10] nEPT: Advertise EPT to L1 Nadav Har'El
2011-11-10 10:01 ` [PATCH 08/10] nEPT: Nested INVEPT Nadav Har'El
2011-11-10 12:17 ` Avi Kivity
2011-12-11 14:24 ` Nadav Har'El
2011-12-11 14:37 ` Avi Kivity
2011-11-10 10:02 ` [PATCH 09/10] nEPT: Documentation Nadav Har'El
2011-11-10 10:02 ` [PATCH 10/10] nEPT: Miscelleneous cleanups Nadav Har'El
2011-11-10 12:26 ` [PATCH 0/10] nEPT: Nested EPT support for Nested VMX Avi Kivity
2011-11-13 8:52 ` Nadav Har'El
2011-11-13 9:21 ` Avi Kivity
2011-12-12 11:37 ` Nadav Har'El
2011-12-12 13:04 ` Avi Kivity
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