From: "H. Peter Anvin" <hpa@zytor.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Alex Shi <alex.shi@intel.com>, Will Drewry <wad@chromium.org>,
Kees Cook <keescook@chromium.org>, Julien Tinnes <jln@google.com>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Dan Rosenberg <drosenberg@vsecurity.com>,
"x86@kernel.org" <x86@kernel.org>,
Borislav Petkov <borislav.petkov@amd.com>,
Steven Rostedt <rostedt@goodmis.org>,
"virtualization@lists.linux-foundation.org"
<virtualization@lists.linux-foundation.org>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Ingo Molnar <mingo@redhat.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [Xen-devel] Readonly GDT
Date: Wed, 10 Apr 2013 11:28:00 -0700 [thread overview]
Message-ID: <5165AF30.909@zytor.com> (raw)
In-Reply-To: <5165502902000078000CC022@nat28.tlf.novell.com>
On 04/10/2013 02:42 AM, Jan Beulich wrote:
>
>> However, the packing solution has the advantage of reducing address
>> space consumption which matters on 32 bits: even on i386 we can easily
>> burn a megabyte of address space for 4096 processors, but burning 16
>> megabytes starts to hurt.
>
> Packing would have the additional benefit of Xen not needing to
> become a special case in yet another area (because pages
> containing live descriptor table entries need to be read-only for
> PV guests, and need to consist of only descriptor table entries).
>
OK, so on 64 bits this sounds like a win all around, whereas it is not
feasible on 32 bits (which means we don't really need to worry about
burning address space.)
So, anyone interested in implementing this for 64 bits?
-hpa
next prev parent reply other threads:[~2013-04-10 18:28 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-08 22:43 [PATCH] x86: make IDT read-only Kees Cook
2013-04-08 22:47 ` H. Peter Anvin
2013-04-08 22:55 ` Kees Cook
2013-04-08 22:48 ` H. Peter Anvin
2013-04-09 9:23 ` Thomas Gleixner
2013-04-09 9:45 ` Eric W. Biederman
2013-04-10 9:57 ` Ingo Molnar
2013-04-10 10:40 ` Eric W. Biederman
2013-04-10 16:31 ` Eric Northup
2013-04-10 16:48 ` H. Peter Anvin
[not found] ` <alpine.LFD.2.02.1304091122490.21884@ionos>
2013-04-09 18:22 ` [kernel-hardening] " Kees Cook
2013-04-09 18:26 ` H. Peter Anvin
2013-04-09 18:31 ` Kees Cook
2013-04-09 18:39 ` H. Peter Anvin
2013-04-09 18:46 ` Kees Cook
2013-04-09 18:50 ` H. Peter Anvin
2013-04-09 18:53 ` Kees Cook
2013-04-09 18:54 ` Eric Northup
2013-04-09 18:59 ` H. Peter Anvin
2013-04-10 0:43 ` Readonly GDT H. Peter Anvin
2013-04-10 0:53 ` Steven Rostedt
2013-04-10 0:58 ` H. Peter Anvin
2013-04-10 9:42 ` [Xen-devel] " Jan Beulich
2013-04-10 14:16 ` H. Peter Anvin
2013-04-10 18:28 ` H. Peter Anvin [this message]
2013-04-10 9:41 ` [kernel-hardening] Re: [PATCH] x86: make IDT read-only Ingo Molnar
2013-04-10 0:03 ` H. Peter Anvin
2013-04-10 9:52 ` Ingo Molnar
2013-04-08 22:56 ` Maciej W. Rozycki
[not found] ` <alpine.LFD.2.03.1304082350540.25182@linux-mips.org>
2013-04-08 23:00 ` Kees Cook
2013-04-08 23:05 ` Kees Cook
2013-04-08 23:42 ` Maciej W. Rozycki
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