From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3AA3712B63 for ; Thu, 7 Sep 2023 15:51:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1694101886; x=1725637886; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=6EsGUJGhX1zT+Uyl+vPXWvJ0hitAvo76hypLco20y4Y=; b=eQzq+RuxCvmYs5gwVa0CmmuEn6yIa/PyxstvRIhlNdG+Xq/KRDlb25h+ FbrxDiwfEDgIOmMcP+yH51LU/A90/Wk/w6mXj/pv2FIjM//mhHgIOBIgf bkoK+cCHlIPibWfJYP+cmVUNfNEr4P7MqE4BRFaaLyILHWIUlcWrQ09Dn TXliaHy7A9Q74ZZY12brulsYj3LZIEl7V3/dthqK86SUrgfB2X9IsVHXV /RJ4agUQ+V5SL8mnp0XcEqPo1qLm6ab6rAxsWrc8Y7xzsY/eTQ++iw5pM 5Wd5hSdixKn56OgiKZrAAAhBiCh4iDlJ8I/grRsGz41osIwqDgYy5YzjE Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10826"; a="408388052" X-IronPort-AV: E=Sophos;i="6.02,235,1688454000"; d="scan'208";a="408388052" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2023 08:51:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10826"; a="915793424" X-IronPort-AV: E=Sophos;i="6.02,235,1688454000"; d="scan'208";a="915793424" Received: from ningle-mobl2.amr.corp.intel.com (HELO [10.209.13.77]) ([10.209.13.77]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Sep 2023 08:51:06 -0700 Message-ID: <5a188bb6-add4-0522-069f-18fbd34aff16@intel.com> Date: Thu, 7 Sep 2023 08:51:06 -0700 Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.0 Subject: Re: [PATCH 1/3] proc/vmcore: Do not map unaccepted memory Content-Language: en-US To: Adrian Hunter , "Kirill A. Shutemov" , Borislav Petkov , Andrew Morton Cc: Vlastimil Babka , Mike Rapoport , Lorenzo Stoakes , Tom Lendacky , Baoquan He , Vivek Goyal , Dave Young , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, kexec@lists.infradead.org References: <20230906073902.4229-1-adrian.hunter@intel.com> <20230906073902.4229-2-adrian.hunter@intel.com> <21bf2e44-3316-2372-44cb-1488f88650f5@intel.com> <30d0cebb-13f9-572e-9baa-b7450fec9108@intel.com> From: Dave Hansen In-Reply-To: <30d0cebb-13f9-572e-9baa-b7450fec9108@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 9/7/23 08:44, Adrian Hunter wrote: > On 7/09/23 18:39, Dave Hansen wrote: >> On 9/6/23 00:39, Adrian Hunter wrote: >>> @@ -559,7 +567,8 @@ static int vmcore_remap_oldmem_pfn(struct vm_area_struct *vma, >>> * pages without a reason. >>> */ >>> idx = srcu_read_lock(&vmcore_cb_srcu); >>> - if (!list_empty(&vmcore_cb_list)) >>> + if (!list_empty(&vmcore_cb_list) || >>> + range_contains_unaccepted_memory(paddr, paddr + size)) >>> ret = remap_oldmem_pfn_checked(vma, from, pfn, size, prot); >>> else >>> ret = remap_oldmem_pfn_range(vma, from, pfn, size, prot); >> The whole callback mechanism which fs/proc/vmcore.c::pfn_is_ram() >> implements seems to be in place to ensure that there aren't a billion >> different "ram" checks in here. >> >> Is there a reason you can't register_vmcore_cb() a callback to check for >> unaccepted memory? > Someone asked for the change to be in arch-independent code... 😉 That doesn't really answer my question. virtio_mem_init_kdump(), for instance, is in arch-independent code.