From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x232.google.com (mail-pg0-x232.google.com [IPv6:2607:f8b0:400e:c05::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40LkGq2w3nzDqwP for ; Wed, 11 Apr 2018 22:43:14 +1000 (AEST) Received: by mail-pg0-x232.google.com with SMTP id d6so717508pgt.3 for ; Wed, 11 Apr 2018 05:43:14 -0700 (PDT) Date: Wed, 11 Apr 2018 22:43:00 +1000 From: Nicholas Piggin To: Balbir Singh Cc: "open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)" Subject: Re: [PATCH v2] powerpc/config: powernv_defconfig updates Message-ID: <20180411224300.4ce97dc7@roar.ozlabs.ibm.com> In-Reply-To: References: <20180411091203.28141-1-npiggin@gmail.com> <20180411204209.6f7e1a05@roar.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 11 Apr 2018 22:24:06 +1000 Balbir Singh wrote: > On Wed, Apr 11, 2018 at 8:42 PM, Nicholas Piggin wrote: > > On Wed, 11 Apr 2018 20:04:45 +1000 > > Balbir Singh wrote: > > > >> On Wed, Apr 11, 2018 at 7:12 PM, Nicholas Piggin wrote: > >> > For consideration: > >> > > >> > * Add IPv6 support built in + additional modules - Because it's 2018 maan. > >> > * Add DEFERRED_STRUCT_PAGE_INIT - Let's see what breaks. > >> > >> We did not find any benefits with this on a P8 in terms of boot time > >> with large memory. May be worth reinvestigating > > > > Worth putting in the defconfig just for testing until then? > > Absolutely! > > > > >> > >> > * Add PPC_MEMTRACE - Small powernv debugfs driver for getting hardware traces. > >> > * Add MEMORY_FAILURE - Machine check exceptions can now drive memory failure. > > > > ^^^^ > > Okay for this one? > > Yep definitely! > > > > >> > * Turn on FANOTIFY - This is the current filesystem notification feature. > >> > * Turn on SCOM_DEBUGFS - Handy for hardware/firmware debugging, security risk? > >> > >> Yep, should not be in defconfig, IMHO > > > > Why not? Honest question, I hear some things about secure > > boot when I ask about this option but I'm not quite sure why, or > > what we are securing here. > > > > If the firmware does not want us to mess with scoms, it should > > restrict the call, no? > > > > Yes, firmware definitely should. Do we need inband debugging? I think it's a matter of convenience when testing and debugging things. OTOH I haven't used it a great deal myself. Others do want it if we can just ensure firmware will do the right thing if we're in some secure configuration. Thanks, Nick