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=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 7A0C9C4338F for ; Tue, 10 Aug 2021 17:03:47 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 3C3C660E9B for ; Tue, 10 Aug 2021 17:03:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3C3C660E9B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.165448.302330 (Exim 4.92) (envelope-from ) id 1mDVA5-0006oT-1n; Tue, 10 Aug 2021 17:03:33 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 165448.302330; Tue, 10 Aug 2021 17:03:33 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mDVA4-0006oM-VA; Tue, 10 Aug 2021 17:03:32 +0000 Received: by outflank-mailman (input) for mailman id 165448; Tue, 10 Aug 2021 17:03:31 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mDVA3-0006oG-HP for xen-devel@lists.xenproject.org; Tue, 10 Aug 2021 17:03:31 +0000 Received: from mail-lf1-x12b.google.com (unknown [2a00:1450:4864:20::12b]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id bfdc5560-719f-4237-8d79-84ef8fea4f1c; Tue, 10 Aug 2021 17:03:30 +0000 (UTC) Received: by mail-lf1-x12b.google.com with SMTP id w20so16280711lfu.7 for ; Tue, 10 Aug 2021 10:03:30 -0700 (PDT) Received: from [192.168.1.7] ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id x81sm1743220lff.245.2021.08.10.10.03.28 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 10 Aug 2021 10:03:28 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: bfdc5560-719f-4237-8d79-84ef8fea4f1c DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=faRUuIPg9Z4Z8piSBNv3ntJpdkHk7f4Mg/8pbIgP6wg=; b=N1vN04Sy+gzr9bk4qppOwFq/dIK9/sP5oqEWDztJmmRNUVGJt+KyA/lKgsdiDMrWxH XUFkN70nqinKdAPTnIsVdLJLTgEa4q7IWjvPwY/t0NqRct3/kfEaSTDINL+ErWUYC1Zv ecpFbzkTiJWlkt4b9c+EfB4iZgmdwArJKCxCh8CXrYyptrHsWRq/+cETfZZMa35CmZQF FtWvQPjaIa0A85zzjeuChkAY0K6UxPqc1rkA00uR864ZOke//lHB/6bQib54qGVk1NKj eUn1rYelOemY6bABU6c5gUk+MRGQt4fJ4Q28Ko1zUjBUNEIdM55EdX3hldZAehp4ISFB jqjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=faRUuIPg9Z4Z8piSBNv3ntJpdkHk7f4Mg/8pbIgP6wg=; b=tOO5eM2Cj+z3xa4DJ39HQTpTTKaXYbRkFLkiCwx48raQYmapKnOi4snHw7U2YHDMmx /P+khu4dKNFqrW7RNXROvxAj5ztoT4X1FuCY0lfhlWofX8yNEZ0l7nKEgx4kVr8M620d ipJmN9iDjmW2uiCAakEQtM8Fy4iRHaVidxMbb73ObVgupXYjyHzJ7B+nGh63MILS2EyQ WhesAO3pH2Ae76X3V+MBgt8BLMCYsDQF2B73vJrOHAIdBEhqWAoRcG5IcWORV4LWwYJR +XZ0hgXI0jZboCBpirQLom1mcDmD88M/Y5KX6shOkD3TRwhv9A4Qn6+8NO4Zu3n7uc0G L6EQ== X-Gm-Message-State: AOAM532bfNEAvwk9pPs0z8Y6zPoNnXfueNPtOkG8F7v5VSVaLhpMEGuH uVRP2OapkW5gg5aS3tXZ2bY= X-Google-Smtp-Source: ABdhPJzp2wJLRW+bPUUAi93mZPsoGkhA3N0a8Tb7wiT7/ggkph9qpm8Ufl4ORuIvnu4sDs55i4GoNQ== X-Received: by 2002:ac2:4569:: with SMTP id k9mr1705227lfm.178.1628615009445; Tue, 10 Aug 2021 10:03:29 -0700 (PDT) Subject: Re: [RFC PATCH] xen/memory: Introduce a hypercall to provide unallocated space To: Julien Grall Cc: Stefano Stabellini , Andrew Cooper , xen-devel@lists.xenproject.org, Oleksandr Tyshchenko , Daniel De Graaf , "Daniel P. Smith" , Ian Jackson , Wei Liu , George Dunlap , Jan Beulich , Volodymyr Babchuk , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Bertrand Marquis , Wei Chen References: <1627489110-25633-1-git-send-email-olekstysh@gmail.com> <80fafc01-f063-d6e5-1c08-7ad64550310c@citrix.com> <4de5ed21-379e-b618-44c8-924d88b1a519@citrix.com> <6a633f4e-13e0-4a2b-cf6e-35ef90ae977c@gmail.com> <5643d414-0b76-74a4-2c37-c7a99338d547@gmail.com> <6596ad08-8398-64dd-ef62-cd7bc6f7333e@gmail.com> <1d0ea55d-2e5a-daa7-9c60-c7a1c4b48fa1@gmail.com> <6947db7a-44d3-eb5f-c93e-1c1b88c62f29@xen.org> <736c38b3-0dfa-ccbf-6a6a-6da871f8aca0@gmail.com> <4f5be55d-062b-06d2-1e41-bac3ade0cc3a@xen.org> From: Oleksandr Message-ID: Date: Tue, 10 Aug 2021 20:03:27 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <4f5be55d-062b-06d2-1e41-bac3ade0cc3a@xen.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US On 10.08.21 19:28, Julien Grall wrote: Hi Julien. > > > On 09/08/2021 22:18, Oleksandr wrote: >> >> On 09.08.21 23:45, Julien Grall wrote: >> >> >> Hi Julien > > > Hi Oleksandr, > >>> On 09/08/2021 19:24, Oleksandr wrote: >>>> >>>> On 09.08.21 18:42, Julien Grall wrote: >>>> 1. If IOMMU is enabled for Dom0 -> provide holes found in Host DT >>>> as safe ranges >>>> >>>> I would take into the account holes >= 1MB. >>> >>> May I ask why 1MB? >> >> Nothing special, just thinking to not bother with small regions which >> would not be too useful overall, but could bloat resulting reg property. >> >> Anyway, I would be ok with any sizes. > > I was more interesting with the reasoning behind your choice rather > than saying we want more. > > I agree that we may want to skip smaller region. I am guess that an > high number of small regions will also increase the bookeeping in Linux. > > But I would probably suggest to align the safe region to a 2MB > (superpage for 4KB page granularity) just because the backend (or even > Xen) may be able to do some optimization there. OK, agree regarding the alignment. But, what about the size? I assume, it should be a multiple of 2MB. > > > Cheers, > -- Regards, Oleksandr Tyshchenko