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 X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED812C35247 for ; Tue, 4 Feb 2020 19:06:36 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B352320674 for ; Tue, 4 Feb 2020 19:06:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WlEc94iC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B352320674 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:36560 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iz3Wt-0007R9-VO for qemu-devel@archiver.kernel.org; Tue, 04 Feb 2020 14:06:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:37389) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iz3Vq-0006Qt-O9 for qemu-devel@nongnu.org; Tue, 04 Feb 2020 14:05:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iz3Vp-0002rs-5W for qemu-devel@nongnu.org; Tue, 04 Feb 2020 14:05:30 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:29749 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iz3Vp-0002l9-0Z for qemu-devel@nongnu.org; Tue, 04 Feb 2020 14:05:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580843126; 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:autocrypt:autocrypt; bh=GJl7xz+itBOchxke9MnYyD6nuiPmgjaVDcgsWqt/pNU=; b=WlEc94iCM46252haULKYRGsz3aOrAQFTUD5i1G2C3I/FP5QgDM5YPTr7p5ytcRmB/LjZUS oNxqsOsBR8eJM1n5qsN+ARtiWQZi/4VaALrOTMKCn3BHXVUa5tmegOcit7wJyaFOZUz+JG j/qV33m4NgpssR2rXY7l9a2dBXkvWSk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-98-aQ4pMFncPe2NX_wOcDtKPw-1; Tue, 04 Feb 2020 14:05:14 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9B799A3718; Tue, 4 Feb 2020 19:05:12 +0000 (UTC) Received: from [10.36.116.24] (ovpn-116-24.ams2.redhat.com [10.36.116.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id 11B9E19C69; Tue, 4 Feb 2020 19:05:04 +0000 (UTC) Subject: Re: [PATCH v2 1/7] exec: Fix for qemu_ram_resize() callback From: David Hildenbrand To: Igor Mammedov , Shameer Kolothum References: <20200117174522.22044-1-shameerali.kolothum.thodi@huawei.com> <20200117174522.22044-2-shameerali.kolothum.thodi@huawei.com> <20200204162320.67e5d353@redhat.com> <74eaaa45-0d20-9a21-fbf8-6d29deb248eb@redhat.com> Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: <4ce41554-8b8e-dbb5-5fe9-43af09950f23@redhat.com> Date: Tue, 4 Feb 2020 20:05:04 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <74eaaa45-0d20-9a21-fbf8-6d29deb248eb@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: aQ4pMFncPe2NX_wOcDtKPw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peter.maydell@linaro.org, xiaoguangrong.eric@gmail.com, mst@redhat.com, shannon.zhaosl@gmail.com, qemu-devel@nongnu.org, xuwei5@hisilicon.com, linuxarm@huawei.com, eric.auger@redhat.com, qemu-arm@nongnu.org, lersek@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 04.02.20 17:44, David Hildenbrand wrote: > On 04.02.20 16:23, Igor Mammedov wrote: >> On Fri, 17 Jan 2020 17:45:16 +0000 >> Shameer Kolothum wrote: >> >>> If ACPI blob length modifications happens after the initial >>> virt_acpi_build() call, and the changed blob length is within >>> the PAGE size boundary, then the revised size is not seen by >>> the firmware on Guest reboot. The is because in the >>> virt_acpi_build_update() -> acpi_ram_update() -> qemu_ram_resize() >>> path, qemu_ram_resize() uses used_length (ram_block size which is >>> aligned to PAGE size) and the "resize callback" to update the size >>> seen by firmware is not getting invoked. >>> >>> Hence make sure callback is called if the new size is different >>> from original requested size. >>> >>> Signed-off-by: Shameer Kolothum >>> --- >>> Please find the previous discussions on this issue here, >>> https://patchwork.kernel.org/patch/11174947/ >>> >>> But this one attempts a different solution to fix it by introducing >>> req_length var to RAMBlock struct. >>> >> >> looks fine to me, so >> Acked-by: Igor Mammedov > > Thanks for CCing. > > This in fact collides with my changes ... but not severely :) > >> >> CCing David who touches this area in his latest series for and >> might have an opinion on how it should be handled. >> > > So we are talking about sub-page size changes? I somewhat dislike > storing "req_length" in ram blocks. Looks like sub-pages stuff does not > belong there. > > Ram blocks only operate on page granularity. Ram block notifiers only > operate on page granularity. Memory regions only operate on page > granularity. Dirty bitmaps operate on page granularity. Especially, > memory_region_size(mr) will always return aligned values. > > I think users/owner should deal with anything smaller manually if > they really need it. > > What about always calling the resized() callback and letting the > actual owner figure out if the size changed on sub-page granularity > or not? (by looking up the size manually using some mechanism not glued to > memory regions/ram blocks/whatever) > > diff --git a/exec.c b/exec.c > index 67e520d18e..59d46cc388 100644 > --- a/exec.c > +++ b/exec.c > @@ -2130,6 +2130,13 @@ int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp) > newsize = HOST_PAGE_ALIGN(newsize); > > if (block->used_length == newsize) { > + /* > + * The owner might want to handle sub-page resizes. We only provide > + * the aligned size - because ram blocks are always page aligned. > + */ > + if (block->resized) { > + block->resized(block->idstr, newsize, block->host); > + } > return 0; > } > Oh, and one more reason why the proposal in this patch is inconsistent: When migrating resizable memory regions (RAM_SAVE_FLAG_MEM_SIZE) we store the block->used_length (ram_save_setup()) and use that value to resize the region on the target (ram_load_precopy() -> qemu_ram_resize()). This will be the value the callback will be called with. Page aligned. -- Thanks, David / dhildenb