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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B78AD15D84 for ; Mon, 21 Oct 2024 12:19:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 05E126B0083; Mon, 21 Oct 2024 08:19:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 00E636B0088; Mon, 21 Oct 2024 08:19:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E17A66B0089; Mon, 21 Oct 2024 08:19:30 -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 C48B26B0083 for ; Mon, 21 Oct 2024 08:19:30 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 8411B41890 for ; Mon, 21 Oct 2024 12:19:21 +0000 (UTC) X-FDA: 82697514438.26.3CD429E Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf15.hostedemail.com (Postfix) with ESMTP id 1B7E2A000A for ; Mon, 21 Oct 2024 12:19:12 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=itBqERyJ; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf15.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1729513131; a=rsa-sha256; cv=none; b=4HDbCpQZGzh3lCy6aJEDWmqQ5bdYgZjCq3YFVo4KZce6BfoBpReF1+UOxrGELEBvI7tq9B nk8dsHe/FqshvAsuMNp43jGDUkdr+3ixwIAVbTlX+K+M52ppVSj8Y7kO2R38cDumKIFDeY 4fv7skSLBiqiRkNc1CnjobQb/YzbTIY= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=itBqERyJ; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf15.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1729513131; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=3SSNANQOGj1r9ayrCBzVvFmFj/ChOB3ieC2hxuoZm3o=; b=HH7HcQvs5h9fE4W7SyctGcPKDASSKM0OAMjPp4MfusDB/YcvdB9T9Raz72ZTSSHZ8hVhEf /g5SHgUhXwHX/LouYtJVVsIXZdimT7iVM8H6GbM1E84XbS8NyOO6TH2T9r7RjZWH81nR8e lVi1uMWKQ9vMOvNiR/rXvvsuf4FejII= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1729513167; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3SSNANQOGj1r9ayrCBzVvFmFj/ChOB3ieC2hxuoZm3o=; b=itBqERyJZx0C2HdogBZrG1iHhbTD+RVGYjGo8WQyOwltnzNBy58AqH6ro8TNzpLRkxKfWp Ghvv3brzegyNpke9jO2nji55JSLzY5N46YCYOlXaLUHP98x3wvsr2abHHaXYNmm06pJFJe jmt/atFFhosb9d41FV9VbifIoXhVQHI= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-203-IS3aqyroPCCRsDeQv6cCrA-1; Mon, 21 Oct 2024 08:19:26 -0400 X-MC-Unique: IS3aqyroPCCRsDeQv6cCrA-1 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-4315a0f25afso32372355e9.3 for ; Mon, 21 Oct 2024 05:19:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729513165; x=1730117965; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3SSNANQOGj1r9ayrCBzVvFmFj/ChOB3ieC2hxuoZm3o=; b=QyvQRO9Cdi72I43SGqXjqmUsSiDgp6DxUC81NTIAlTIvkYx6kfQwRYXp3bokxe5V6D +nhee+pD5OZp9wS7cI7/AblY24TENff3H4iZpyzkUu/Py+SmLxFm8LehC+64Hf5E8qRJ q5ZQqk4qqbd16zAN5Cf3tFW8aEuFzbCObRLsy46+Q1mMz3d3HP0f+RFbKGUhJvWqxR3p Lb7H6gsbVhvxanmDqEyZ5Rat3XESimU0Um+/FvZwxCf1yYyAEKo5Gg5f50TUe6Mxc0Su WDJaZJPbb4ricFIYb3i+hyuaI/mIFziMIUUCWNP/w1h/Idfem2NWn6znPYbw0vYgIJLO KPLQ== X-Forwarded-Encrypted: i=1; AJvYcCXVPQMpRWWziDcY3Qv/FhAm3zWKsmYmV9fHUPiQNRpXNzTDqDI8W0J6qIEUsYBEdiTav9J9dOt3Kg==@kvack.org X-Gm-Message-State: AOJu0YzwFvec6yEVtZgVFwAci6o5mi2O4WNsNqqHc3E1JBjyaZP0nq7G LZWbL+kndalkFNp9wBxJBc3aerztCGbIcajImUCzn3vtdUJLmQxxI0dPe6JIU1290s9rTRK/Hvy RqVHc5NpvNqLLyoBtp5c37d3n9nYNr7H3v/Dn/hVCpQ0uquhgKKexrVlfpHw= X-Received: by 2002:a05:600c:4e12:b0:431:1d97:2b0a with SMTP id 5b1f17b1804b1-43161641793mr95708035e9.15.1729513164993; Mon, 21 Oct 2024 05:19:24 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHL+4zTIZRaHCwKu0OkK2nf7jN/ima55H0fGeAQpNI8aBlBlaAzYq2yIrtU/CEO+/V54e4DoQ== X-Received: by 2002:a05:600c:4e12:b0:431:1d97:2b0a with SMTP id 5b1f17b1804b1-43161641793mr95707665e9.15.1729513164570; Mon, 21 Oct 2024 05:19:24 -0700 (PDT) Received: from ?IPV6:2a09:80c0:192:0:36d3:2b96:a142:a05b? ([2a09:80c0:192:0:36d3:2b96:a142:a05b]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4316f57fa4fsm56089275e9.16.2024.10.21.05.19.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 21 Oct 2024 05:19:24 -0700 (PDT) Message-ID: <213b6a6a-3594-4bc5-ae6d-930bbaf3616d@redhat.com> Date: Mon, 21 Oct 2024 14:19:20 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 5/7] virtio-mem: s390 support To: Christian Borntraeger , Heiko Carstens Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, virtualization@lists.linux.dev, linux-doc@vger.kernel.org, kvm@vger.kernel.org, Vasily Gorbik , Alexander Gordeev , Sven Schnelle , Thomas Huth , Cornelia Huck , Janosch Frank , Claudio Imbrenda , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Andrew Morton , Jonathan Corbet , Mario Casquero References: <20241014144622.876731-1-david@redhat.com> <20241014144622.876731-6-david@redhat.com> <20241014184824.10447-F-hca@linux.ibm.com> <20241015083750.7641-D-hca@linux.ibm.com> From: David Hildenbrand In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: iasbqt6o9ashqcngatnuohw79przw89p X-Rspamd-Queue-Id: 1B7E2A000A X-Rspamd-Server: rspam02 X-HE-Tag: 1729513152-968213 X-HE-Meta: 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 qHQdkOcG Zn0RQrLgkMpDOzA37OtLslDnjhElv6DfsEn9qNF4YKeoooVwJiFu9z/iKGEtSI1f35TZzv/F28HRqKZtvL0q+XeeaBWrOpAMLJaS7Qj3mSdQ1dAJB9EbWZr4hpsFR6WClQCUniMLiFv07a8KkrVzwzbn8ekPoyNodn3gZ05m6Kb5sdqLPkuykJvNK3xQd6PuBmYBfDmbvPIPv0/Zb3NDe3Z3kVQy9jvuDhizYJfBC6ks/auedtNBnExDLwTnpRBsYehTazdcDXXGN9/1jQ5qEgFb1/PyYQYYp9LywrttUPZRH7ntgLeNdjwBC1nx4NKPu5N5zvJho9yXL/PlhF3CWuf4pVUsSBVoJwpcY5jRTSWjU1+zig1DF2owL/O/rCkOWxKA9MX3Aug/c8Ee5TTCp8FwDcz9VZQq95zXtApGRqniAO9A= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Am 21.10.24 um 08:33 schrieb Christian Borntraeger: > > > Am 15.10.24 um 10:37 schrieb Heiko Carstens: >> On Mon, Oct 14, 2024 at 09:16:45PM +0200, David Hildenbrand wrote: >>> On 14.10.24 20:48, Heiko Carstens wrote: >>> >>> The cover letter is clearer on that: "One remaining work item is kdump >>> support for virtio-mem memory. This will be sent out separately once initial >>> support landed." >>> >>> I had a prototype, but need to spend some time to clean it up -- or find >>> someone to hand it over to clean it up. >>> >>> I have to chose wisely what I work on nowadays, and cannot spend that time >>> if the basic support won't get ACKed. >>> >>> >>> For many production use cases it certainly needs to exist. >>> >>> But note that virtio-mem can be used with ZONE_MOVABLE, in which case mostly >>> only user data (e.g., pagecache,anon) ends up on hotplugged memory, that >>> would get excluded from makedumpfile in the default configs either way. >>> >>> It's not uncommon to let kdump support be added later (e.g., AMD SNP >>> variants). >> >> I'll leave it up to kvm folks to decide if we need kdump support from >> the beginning or if we are good with the current implementation. > > If David confirms that he has a plan for this, I am fine with a staged approach > for upstream. I do have a plan and a even a semi-working prototype that I am currently improving. In summary, the virtio-mem driver in kdump mode can report ranges with plugged memory to the core so we can include them in the elfcore hdr. That is the easy part. The "challenge" is when the virtio-mem driver is built as a module and gets loaded after building/allocating the elfcore hdr (which happens when creating /proc/vmcore). We have to defer detecting+adding the ranges to the time /proc/vmcore gets opened. Not super complicated, but needs some thought to get it done in a clean way / with minimal churn. -- Cheers, David / dhildenb