From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7CEA2C982CF for ; Thu, 17 Sep 2026 10:54:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 505696B008A; Thu, 17 Sep 2026 06:54:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 490506B008C; Thu, 17 Sep 2026 06:54:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3583E6B0092; Thu, 17 Sep 2026 06:54:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 0D9156B008A for ; Thu, 17 Sep 2026 06:54:49 -0400 (EDT) Received: from smtpin11.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 03265C02CA for ; Thu, 17 Sep 2026 10:54:47 +0000 (UTC) X-FDA: 85222946256.11.9CDC373 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) by imf01.hostedemail.com (Postfix) with ESMTP id 4261B40007 for ; Thu, 17 Sep 2026 10:54:46 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=debian.org header.s=smtpauto.stravinsky header.b=JrNMbJz0; spf=pass (imf01.hostedemail.com: domain of leitao@debian.org designates 82.195.75.108 as permitted sender) smtp.mailfrom=leitao@debian.org; dmarc=pass (policy=none) header.from=debian.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1789642486; b=v6SlMMDkVT9crWvhR9+ggbgussVntr9Te/lUnVTwhcGm5z9mh7ztJBof7nu2GoNqz5F+7f FTbOYk9EKrykOZREK4nA1znMWlduEZIa6lslFfc9BNcP4aoVrbOjmTGlb2DBwv3MOZgrMx 2loZsc0Z95LVpI6QDNJ4vmwjY5mIb3U= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=debian.org header.s=smtpauto.stravinsky header.b=JrNMbJz0; spf=pass (imf01.hostedemail.com: domain of leitao@debian.org designates 82.195.75.108 as permitted sender) smtp.mailfrom=leitao@debian.org; dmarc=pass (policy=none) header.from=debian.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1789642486; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=zPEyYPDk8EE/aISYlZkkyB6RhrWT5mJK2Kdv46y7alY=; b=0jqgJQN4boQ4Smj9hvPFEv+SePZL6hpSgvrSK0tlTN1y9IVTgqEiiYkfOWhq53bOQwpLYj qX4dSMryS0vtwuUIP4YJldhLhXfWSazEN1miZAbivotogppACznJQH9zSe4mSbR9FldM3J O2qoga7QxbPRWKJVvLVmc1OIQFcvCwI= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=zPEyYPDk8EE/aISYlZkkyB6RhrWT5mJK2Kdv46y7alY=; b=JrNMbJz0FRUfJExTa9QX+PN6aX rhxoAQEs1iGB1gBE7OpxWvUIW8oaZJ+3qq36mNpM298qJUbpa6EV1l5ropOVv08fE6+gDxVbt6av4 Hje1sXASq15UoTMM5biKhP59WUt5uM2mWizZ94hEA12cJeo+YKdwyq+FNA7cJwVDWzLzaLdEZ1Yn7 bI4fAjT372GztJPzZsd7s8hbZJRyvaQhKvOYlC+Wbxp8OBHWPoY+w4qH7drvLUU9cVqE9vQmnJdT2 we/GkdA4e8zC/Yrde1HYP1gljPaqZExfeBTOr8SiZVVolX2RERZBv5A/c7kAkxWLzR1xyVPxeBfsY xou5+GnA==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1x79kQ-005tLG-0g; Thu, 17 Sep 2026 10:53:46 +0000 Date: Thu, 17 Sep 2026 03:53:37 -0700 From: Breno Leitao To: Usama Arif Cc: Ilias Apalodimas , Miaohe Lin , Naoya Horiguchi , Andrew Morton , kas@kernel.org, kexec@lists.infradead.org, David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , hannes@cmpxchg.or, shakeel.butt@linux.dev, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rmikey@meta.com, riel@surriel.com, harry@kernel.org, linux-cxl@vger.kernel.org, driver-core@lists.linux.dev, kernel-team@meta.com Subject: Re: [PATCH v5 3/9] mm/memory-failure: libstub: install the poisoned-memory EFI table Message-ID: References: <20260915-hwpoison-kho-v5-3-3bc7a57bd503@debian.org> <20260916153954.1054456-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260916153954.1054456-1-usama.arif@linux.dev> X-Debian-User: leitao X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 4261B40007 X-Rspam-User: X-Stat-Signature: 8wbqrhhd5an8wx5bxmdg73r39z4bjqz5 X-HE-Tag: 1789642486-924914 X-HE-Meta: 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 iCkXEAI+ mKeQVxD6CoVus6W9imfva8Yzo1/BArPnjzJ/soBt4xvcHYZ5jDfV9+SXcg2HI4elJiErBSkN3fNqPhoDvhyR2CIfHokGom5Tk0/dGQVVARz5aX4PWwfl6toil/WBoBQ34at3HSpDRnx8IAUbAMC7+oMc0HksEkXL5bzFnh671imCLUWV8czmo4qMefMLIcg1RlasU6da6zt4UT8LGf3X21H+thOLkijC7/T6X778ZpAOrTpPjclNocdBJ81bfWegzEcdnCLU/Dc64ylI6bCJ/z5Ddq/AUUVTR7foBgxJAAr3nykgNy7yaJ4HGpE0MAfY17GVSTajb8eVNcvfq6TtRyQuwqQcZel106xDJ5+YB+PuKnFrrHvvxXhv8zQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello Usama, On Wed, Sep 16, 2026 at 08:39:53AM -0700, Usama Arif wrote: > On Tue, 15 Sep 2026 05:53:37 -0700 Breno Leitao wrote: > > +static efi_status_t efi_get_ram_range(u64 *base, u64 *top) > > +{ > > + struct efi_boot_memmap *map __free(efi_pool) = NULL; > > + u64 ram_base = ULLONG_MAX, ram_top = 0; > > + efi_status_t status; > > + int i, nr_desc; > > + > > + status = efi_get_memory_map(&map, false); > > + if (status != EFI_SUCCESS) > > + return status; > > + > > + nr_desc = map->map_size / map->desc_size; > > + for (i = 0; i < nr_desc; i++) { > > + efi_memory_desc_t *d; > > + > > + d = efi_memdesc_ptr((unsigned long)map->map, map->desc_size, i); > > + if (!(d->attribute & EFI_MEMORY_WB) && > > + d->type != EFI_UNACCEPTED_MEMORY) > > + continue; > > + ram_base = min(ram_base, d->phys_addr); > > Can this use the architecture's full RAM predicate? On x86, > setup_e820() maps EFI_LOADER_CODE, EFI_LOADER_DATA, both boot-services > types, and EFI_CONVENTIONAL_MEMORY as E820_TYPE_RAM without requiring > EFI_MEMORY_WB. > > If a non-WB descriptor is at either end of RAM, this code omits it > from the bitmap span. efi_hwpoison_record_pfn() then rejects a > poisoned PFN there, so the next kernel can allocate the bad frame. > > One possible way to preserve the x86 behavior before applying the WB rule is: > > if (IS_ENABLED(CONFIG_X86) && > (d->type == EFI_LOADER_CODE || > d->type == EFI_LOADER_DATA || > d->type == EFI_BOOT_SERVICES_CODE || > d->type == EFI_BOOT_SERVICES_DATA || > d->type == EFI_CONVENTIONAL_MEMORY)) > goto include; > if (!(d->attribute & EFI_MEMORY_WB) && > d->type != EFI_UNACCEPTED_MEMORY) > continue; > include: > ram_base = min(ram_base, Sure, I had something similar in v2, but the feedback there was to simplify this and go coarser, since the real cost is only a few extra bits in the bitmap, so it wasn't worth the added complexity. Happy to bring it back if saving those bits is worthwhile. See the discussion here: https://lore.kernel.org/all/aogvGXKH2u7JsJiS@thinkstation/ Thanks for the review, --breno