From: Ian Campbell <ian.campbell@citrix.com>
To: Tamas K Lengyel <tamas.lengyel@zentific.com>
Cc: Tim Deegan <tim@xen.org>, Julien Grall <julien.grall@linaro.org>,
Ian Jackson <ian.jackson@eu.citrix.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
Stefano Stabellini <stefano.stabellini@citrix.com>,
Andres Lagar-Cavilla <andres@lagarcavilla.org>,
Jan Beulich <jbeulich@suse.com>,
Daniel De Graaf <dgdegra@tycho.nsa.gov>,
Tamas K Lengyel <tklengyel@sec.in.tum.de>
Subject: Re: [PATCH for-4.5 v6 12/17] xen/arm: Implement domain_get_maximum_gpfn
Date: Tue, 16 Sep 2014 17:44:38 +0100 [thread overview]
Message-ID: <1410885878.23505.14.camel@citrix.com> (raw)
In-Reply-To: <CAErYnsg1XpqP3zC0zKEhbMb2DunYDYYcLGJ7k9QixK_73M645g@mail.gmail.com>
On Tue, 2014-09-16 at 10:02 +0200, Tamas K Lengyel wrote:
> Certainly. The reason we use this in xenaccess is to avoid the user
> attempting to set page permissions on pages which don't exist for the
> domain. For example, if the user attempts to set page permissions from
> gpfn 0 -> (~0-1), it will waste a lot of the hypervisors time. It
> won't break anything as non-existent pages are skipped automatically,
> and now with the preemption in place it can't DoS the system, but it's
> still a reasonable sanity check to perform. It's not a comprehensive
> enforcement of 'don't try to set permission on non-existent pages' as
> ARM has holes in the memory layout and doesn't start from 0, but this
> check at least works for both x86 and ARM.
OK. Please can you include this in the commit message.
next prev parent reply other threads:[~2014-09-16 16:44 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-15 14:02 [PATCH for-4.5 v6 00/17] Mem_event and mem_access for ARM Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 01/17] xen: Relocate mem_access and mem_event into common Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 02/17] xen: Relocate p2m_mem_access_resume to mem_access common Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 03/17] xen: Relocate struct npfec definition into common Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 04/17] xen: Relocate mem_event_op domctl and access_op memop " Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 05/17] x86/p2m: Typo fix for spelling ambiguous Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 06/17] xen/mem_event: Clean out superfluous white-spaces Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 07/17] xen/mem_event: Relax error condition on debug builds Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 08/17] xen/mem_event: Abstract architecture specific sanity checks Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 09/17] xen/mem_access: Abstract architecture specific sanity check Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 10/17] xen/arm: p2m type definitions and changes Tamas K Lengyel
2014-09-15 22:35 ` Ian Campbell
2014-09-16 8:49 ` Tamas K Lengyel
2014-09-16 13:27 ` Ian Campbell
2014-09-16 20:38 ` Julien Grall
2014-09-16 21:52 ` Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 11/17] xen/arm: Add set access required domctl Tamas K Lengyel
2014-09-15 22:37 ` Ian Campbell
2014-09-16 8:37 ` Tamas K Lengyel
2014-09-15 22:38 ` Ian Campbell
2014-09-16 8:33 ` Tamas K Lengyel
2014-09-16 13:25 ` Ian Campbell
2014-09-15 14:02 ` [PATCH for-4.5 v6 12/17] xen/arm: Implement domain_get_maximum_gpfn Tamas K Lengyel
2014-09-15 22:39 ` Ian Campbell
2014-09-16 8:02 ` Tamas K Lengyel
2014-09-16 16:44 ` Ian Campbell [this message]
2014-09-16 17:09 ` Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 13/17] xen/arm: Data abort exception (R/W) mem_events Tamas K Lengyel
2014-09-15 22:53 ` Ian Campbell
[not found] ` <CAErYnshu0vJJMxWwu4eo2MZf=q_g2H123p6VUk_4a9f12vYLjg@mail.gmail.com>
2014-09-16 10:07 ` Tamas K Lengyel
2014-09-16 16:50 ` Ian Campbell
2014-09-16 17:08 ` Tamas K Lengyel
2014-09-18 18:54 ` Ian Campbell
2014-09-18 20:09 ` Tamas K Lengyel
2014-09-19 9:05 ` Tamas K Lengyel
2014-09-22 9:11 ` Ian Campbell
2014-09-22 17:18 ` Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 14/17] xen/arm: Instruction prefetch abort (X) mem_event handling Tamas K Lengyel
2014-09-18 18:59 ` Ian Campbell
2014-09-18 20:12 ` Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 15/17] xen/arm: Enable the compilation of mem_access and mem_event on ARM Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 16/17] tools/libxc: Allocate magic page for mem access " Tamas K Lengyel
2014-09-15 14:02 ` [PATCH for-4.5 v6 17/17] tools/tests: Enable xen-access " Tamas K Lengyel
2014-09-18 19:02 ` Ian Campbell
2014-09-22 18:48 ` Tamas K Lengyel
2014-09-23 12:18 ` Ian Campbell
2014-10-01 17:32 ` Aravindh Puthiyaparambil (aravindp)
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