From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prarit Bhargava Subject: Re: ESRT failures ... was Re: [PATCH 04/11] efi: Add efi_memmap_init_late() for permanent EFI memmap Date: Fri, 22 Jul 2016 09:31:20 -0400 Message-ID: <57922028.7070103@redhat.com> References: <57867F32.8040001@redhat.com> <20160721121136.GF26504@codeblueprint.co.uk> <5790DFD0.4020806@redhat.com> <20160722131101.GJ26504@codeblueprint.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160722131101.GJ26504-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matt Fleming Cc: Lenny Szubowicz , Peter Jones , linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ard Biesheuvel List-Id: linux-efi@vger.kernel.org On 07/22/2016 09:11 AM, Matt Fleming wrote: > On Thu, 21 Jul, at 10:44:32AM, Prarit Bhargava wrote: >> >> >> On 07/21/2016 08:11 AM, Matt Fleming wrote: >>> >>> efi_mem_desc_lookup() should just return the correct EFI memory >>> descriptor now that we have efi_mem_reserve() coming in v4.9. >>> >>> What does the EFI memmap (as printed with efi=debug) look like on your >>> machine? >>> >> >> [ 0.000000] efi: EFI v2.40 by Dell Inc. >> [ 0.000000] efi: ESRT=0x8eb1c000 ACPI=0x8efe7000 ACPI 2.0=0x8efe7014 >> SMBIOS=0x8ef69000 >> >> and >> >> [ 0.000000] efi: mem249: [Reserved | | | | | | | | >> |WB|WT|WC|UC] range=[0x000000008d6df000-0x000000008ef69fff] (24MB) > > Yeah, that's a Dell firmware bug. This should be EFI boot services > data. Quoting the spec Section 22.3 EFI System Resource Table, > > "See Section 4.6 for description of how to publish ESRT using > EFI_CONFIGURATION_TABLE. The ESRT shall be stored in memory of type > EfiBootServicesData." > > We do not use regions mark EFI_RESERVED_TYPE because they're basically > supposed to be unusable by the OS, AFAIK. I guess we'll have to update > efi_mem_desc_lookup() to return reserved regions and make sure they're > always contained within the memmap. > Hmm ... maybe just a Dell specific quirk? P.