From: Nadav Har'El <nyh@math.technion.ac.il>
To: Avi Kivity <avi@redhat.com>
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 17:14:05 +0200 [thread overview]
Message-ID: <20111110151405.GC3327@fermat.math.technion.ac.il> (raw)
In-Reply-To: <4EBBE1CE.5060702@redhat.com>
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.
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).
If you really don't like the existance of this option, I can easily
remove it of course.
--
Nadav Har'El | Thursday, Nov 10 2011,
nyh@math.technion.ac.il |-----------------------------------------
Phone +972-523-790466, ICQ 13349191 |Guarantee: this email is 100% free of
http://nadav.harel.org.il |magnetic monopoles, or your money back!
next prev parent reply other threads:[~2011-11-10 15:14 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 [this message]
2011-11-10 15:21 ` Avi Kivity
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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