linux-kernel - Re: [PATCH 02/14] x86/sgx: Add /sys/kernel/debug/x86/sgx_total

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <26937e79-c7f7-ea08-a4dd-9386a44c4ff1@intel.com>
Date:   Thu, 16 Sep 2021 08:35:35 -0700
From:   Reinette Chatre <reinette.chatre@...el.com>
To:     Jarkko Sakkinen <jarkko@...nel.org>, <linux-sgx@...r.kernel.org>,
        <shuah@...nel.org>
CC:     <seanjc@...gle.com>, <bp@...en8.de>, <dave.hansen@...ux.intel.com>,
        <linux-kselftest@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 02/14] x86/sgx: Add /sys/kernel/debug/x86/sgx_total_mem

Hi Jarkko,

On 9/16/2021 7:09 AM, Jarkko Sakkinen wrote:
> On Wed, 2021-09-15 at 13:30 -0700, Reinette Chatre wrote:
>> From: Jarkko Sakkinen <jarkko@...nel.org>
>>
>> Just like normal memory, SGX memory can be overcommitted.  SGX has its
>> own reclaim mechanism which kicks in when physical SGX memory (Enclave
>> Page Cache / EPC) is exhausted.  That reclaim mechanism is relatively
>> rarely exercised and needs selftests to poke at it.
>>
>> The amount of EPC on the system is determined by the BIOS and it varies
>> wildly between systems.  It can be dozens of MB on desktops, or many GB
>> on servers.
>>
>> To run in a reasonable amount of time, the selftest needs to know how
>> much EPC there is in the system.
>>
>> Introduce a new debugfs file to export that information.
>>
>> Acked-by: Dave Hansen <dave.hansen@...ux.intel.com>
>> Signed-off-by: Jarkko Sakkinen <jarkko@...nel.org>
>> [reinette: Use as placeholder patch until other discussions complete]
>> Signed-off-by: Reinette Chatre <reinette.chatre@...el.com>
> 
> This could be replaced with the following two patches:
> 
> https://lore.kernel.org/linux-sgx/20210914030422.377601-1-jarkko@kernel.org/T/#t
> 

Thank you very much. I will replace this patch and update the kselftest 
changes to use the information from the new source.

Reinette