From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Fleming Subject: Re: [PATCH 1/4] efi/x86: make efi_memmap_reserve only insert into boot mem areas Date: Fri, 27 Jan 2017 14:48:13 +0000 Message-ID: <20170127144813.GE31613@codeblueprint.co.uk> References: <20170112094118.815108042@redhat.com> <20170112094214.860924858@redhat.com> <87r348r0k9.fsf@gmail.com> <20170112212952.GB2709@dhcp-128-65.nay.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20170112212952.GB2709@dhcp-128-65.nay.redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Dave Young Cc: Nicolai Stange , Ard Biesheuvel , linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, Ingo Molnar , Thomas Gleixner , hpa@zytor.com, Dan Williams , mika.penttila@nextfour.com, bhsharma@redhat.com List-Id: linux-efi@vger.kernel.org On Fri, 13 Jan, at 05:29:52AM, Dave Young wrote: > > It sounds reasonable though I'm still not sure about EFI_LOADER*. > > The main purpose of this patch is to address the invalid mem ranges > case. As Ard mentioned I will test with Peter's patch first, if it works > fine I would like to either drop this patch as a future improvement or add > it at the end of the next post. > > Matt, what's your opinion about the boot_only check and the EFI_LOADERS* > question? The main reason that efi_mem_reserve() isn't used for EFI_LOADER regions today is because we already have a mechanism for reserving it via memblock_reserve(), which we do during a very early stage of boot when parsing all the different types of SETUP_* objects. It's questionable whether it would make sense to switch to efi_mem_reserve() for EFI_LOADER regions because then you'd potentially have different APIs for different SETUP_* objects. As things stand today, I would suggest triggering a WARN_ON() if someone tries to efi_mem_reserve() an EFI_LOADER region, until/unless the day comes when a user exists in the kernel.