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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 258C8C433E6 for ; Mon, 1 Feb 2021 21:23:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DA9CC64ED0 for ; Mon, 1 Feb 2021 21:23:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232369AbhBAVXm (ORCPT ); Mon, 1 Feb 2021 16:23:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229525AbhBAVXj (ORCPT ); Mon, 1 Feb 2021 16:23:39 -0500 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDF65C061573 for ; Mon, 1 Feb 2021 13:22:58 -0800 (PST) Received: by mail-oi1-x234.google.com with SMTP id a77so20461328oii.4 for ; Mon, 01 Feb 2021 13:22:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yOWrw7a+Nf/KygeG78AKIm4KgYP1X9MsGHak8Pcn4zg=; b=o5jpmsDsoy2ji8gpSb36ZTjvFoA1b9ZgnxGP7BNO941bOozBAgb85HxfqP7ke9weQZ SpK7oyNLgUjJX2fDxDZQDiKj5OnmmA1iQLR9Pql9Y7kN07+suHgVlZpX849oC7jsFT57 cW0DfuuM2Hw+BuZiiWMrn3sKFp79qYjY1DUgakhu1dQ4GghBwUHxOdFyECtLgJOMYpS7 W8pMJq1aTdPk1qovkiZBrTCtatjVdjA9o1hN0/ieRYZ0JWHw8Q5D/5SEmXQsU5cXpIOn sy0df7yFz7oIgQHyrO6/mHCdDwFjmVgfsBhSFTnEzLu5c/U7EipCXJRYolPbbg8FIuOo 2P8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yOWrw7a+Nf/KygeG78AKIm4KgYP1X9MsGHak8Pcn4zg=; b=ZUMTHmBrXBD08K9pKBCezM6rMdOodyXnIEJ06g8VPhVqsgUZtccKW4fjgYL1dE0/5d NLuvcGYbnqv3vRvvzdLUaeDfCL5xJeC6L+7IR7XuK1s3b6w534K+CfZqvMDw/NvvhNwH LdGFPTGPjEX6rpnoiJk83Ph/gQyLGvpEWhWJGa8bEchl13jfdpHIF+M6Z+KKwsr/7QKm nRC/ZY7boVYc3pP2L6VvI4i0VuLYlAuq+FcEC/7CpDqEjVpDhZumXCm4fHIR1dDSkVMr /k/vVMBaoNS08BaO72QYE/JzoBDtCzihm2tn+j+q5AV3GLzkQM6DF0yBRUlcr9rFGpA1 eKqQ== X-Gm-Message-State: AOAM532aSBP44LRGS//9ukpWoXL62cTXdShuok96IR6dbIYDnVjeoA6K jHuHJY5on2D9xnns8VUawp3M7lnGO6FfRRYqO2ID4g== X-Google-Smtp-Source: ABdhPJwLLr7HE/FPtCzHw8vOCiRi6L3hhZDdCNDFos3jTHmz5rAH077nWm3ycDUwLoEjDXEKNGh/LvplLh9wMECNwRg= X-Received: by 2002:aca:be0b:: with SMTP id o11mr575501oif.42.1612214578188; Mon, 01 Feb 2021 13:22:58 -0800 (PST) MIME-Version: 1.0 References: <20210201183017.3339130-1-jxgao@google.com> <20210201183017.3339130-4-jxgao@google.com> <20210201205759.GA2128135@dhcp-10-100-145-180.wdc.com> In-Reply-To: From: Jianxiong Gao Date: Mon, 1 Feb 2021 13:22:45 -0800 Message-ID: Subject: Re: [PATCH V2 3/3] Adding device_dma_parameters->offset_preserve_mask to NVMe driver. To: Keith Busch Cc: Erdem Aktas , Marc Orr , Christoph Hellwig , m.szyprowski@samsung.com, Robin Murphy , gregkh@linuxfoundation.org, Saravana Kannan , heikki.krogerus@linux.intel.com, rafael.j.wysocki@intel.com, Andy Shevchenko , dan.j.williams@intel.com, bgolaszewski@baylibre.com, jroedel@suse.de, iommu@lists.linux-foundation.org, Konrad Rzeszutek Wilk , axboe@fb.com, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Why is this setting being done and undone on each IO? Wouldn't it be > more efficient to set it once during device initialization? > > And more importantly, this isn't thread safe: one CPU may be setting the > device's dma alignment mask to 0 while another CPU is expecting it to be > NVME_CTRL_PAGE_SIZE - 1. I was having trouble getting the OS booted when setting it once during initialization. However when I rebased to the latest rc6 this morning it seems to be working with setting the mask on probe. I am still testing out and will appreciate any idea what may cause the nvme driver to fail with a single mask. -- Jianxiong Gao 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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C7CB1C433DB for ; Mon, 1 Feb 2021 21:23:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 447EA64ECF for ; Mon, 1 Feb 2021 21:23:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 447EA64ECF Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Rrr+gxVucfN5ftnUJg66x0M/ZWjK+B1P27yqnI77Xqc=; b=1V1a+iqOBbv0jXt/QPOc2Np0u 1/faCddB8SdJDCqrcuPSv80883wgjQCjQofoIsEx94c8+Xn7sGvvF5tbmggWNDbSnLKGGuGviXqts Ae+lTDJUEqhMr4Egj18XJIwLykGZogEud9raks21Pc2q/CpGZF9JxV38Gnyj1fG0TNIwzLX8YzBI7 zAhRYMylS7bKIvKgJOwuDGXOm0+0xvKdEMWpaODu92fKyEj8NvZTb1+DE/9s8/iWNQfgzYEHKP24e Q9n+rpxzn+p+7FNGzndri15beI6vK6FFqAFi9LyLFgiK9ATUSoXAN2Bf/wK9SDm5NG3snYNZVgYBu /hs9QuXPg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6gf0-0002x1-Kf; Mon, 01 Feb 2021 21:23:02 +0000 Received: from mail-oi1-x22f.google.com ([2607:f8b0:4864:20::22f]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l6gey-0002wG-EQ for linux-nvme@lists.infradead.org; Mon, 01 Feb 2021 21:23:01 +0000 Received: by mail-oi1-x22f.google.com with SMTP id k142so6016773oib.7 for ; Mon, 01 Feb 2021 13:22:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yOWrw7a+Nf/KygeG78AKIm4KgYP1X9MsGHak8Pcn4zg=; b=o5jpmsDsoy2ji8gpSb36ZTjvFoA1b9ZgnxGP7BNO941bOozBAgb85HxfqP7ke9weQZ SpK7oyNLgUjJX2fDxDZQDiKj5OnmmA1iQLR9Pql9Y7kN07+suHgVlZpX849oC7jsFT57 cW0DfuuM2Hw+BuZiiWMrn3sKFp79qYjY1DUgakhu1dQ4GghBwUHxOdFyECtLgJOMYpS7 W8pMJq1aTdPk1qovkiZBrTCtatjVdjA9o1hN0/ieRYZ0JWHw8Q5D/5SEmXQsU5cXpIOn sy0df7yFz7oIgQHyrO6/mHCdDwFjmVgfsBhSFTnEzLu5c/U7EipCXJRYolPbbg8FIuOo 2P8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yOWrw7a+Nf/KygeG78AKIm4KgYP1X9MsGHak8Pcn4zg=; b=Gpc1bndDDXLI2ZCM2QFrE8Go6TmrUBQh65ISTLwQyiLSLc+kFyCELLztE3BGPFKIqN XGysuaxOy8IdgD3CeEZodplc6/bpoulvIRJKR8qyiWwesr0zWuz1xQCTJpzfzzcc/BkT erFH0K5LgeHlFCK5nmqXLNzEOozSbnCeKWcuOBcFSpeMLSx/I6WCil4LB3DD6V430oqu ip3Dr0mRqGveecWDaqD3XjRMrUXvPelF4FqrT1dJp/UcybPbrKrS2Hru2ZfWTacza37u X3Jvhthe9oT2Feul1ROEtuw8uzQu9tYnOEQ7vrb+4il0IjvOK8gWm12oCKZPsS3PbjOb cZbg== X-Gm-Message-State: AOAM533z4+PQgvvCkThYonbjKpwqh+JF7c+SfCigbWgh0WsQtEnZQdxI tqgBsgRAElXVPKfaX9ls5UzCRDzlEUTH1wb5VZ36+A== X-Google-Smtp-Source: ABdhPJwLLr7HE/FPtCzHw8vOCiRi6L3hhZDdCNDFos3jTHmz5rAH077nWm3ycDUwLoEjDXEKNGh/LvplLh9wMECNwRg= X-Received: by 2002:aca:be0b:: with SMTP id o11mr575501oif.42.1612214578188; Mon, 01 Feb 2021 13:22:58 -0800 (PST) MIME-Version: 1.0 References: <20210201183017.3339130-1-jxgao@google.com> <20210201183017.3339130-4-jxgao@google.com> <20210201205759.GA2128135@dhcp-10-100-145-180.wdc.com> In-Reply-To: From: Jianxiong Gao Date: Mon, 1 Feb 2021 13:22:45 -0800 Message-ID: Subject: Re: [PATCH V2 3/3] Adding device_dma_parameters->offset_preserve_mask to NVMe driver. To: Keith Busch X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210201_162300_535235_F6EA2F15 X-CRM114-Status: GOOD ( 14.58 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, sagi@grimberg.me, Saravana Kannan , Konrad Rzeszutek Wilk , Marc Orr , gregkh@linuxfoundation.org, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, axboe@fb.com, bgolaszewski@baylibre.com, iommu@lists.linux-foundation.org, jroedel@suse.de, Erdem Aktas , dan.j.williams@intel.com, Andy Shevchenko , Robin Murphy , Christoph Hellwig , m.szyprowski@samsung.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org > Why is this setting being done and undone on each IO? Wouldn't it be > more efficient to set it once during device initialization? > > And more importantly, this isn't thread safe: one CPU may be setting the > device's dma alignment mask to 0 while another CPU is expecting it to be > NVME_CTRL_PAGE_SIZE - 1. I was having trouble getting the OS booted when setting it once during initialization. However when I rebased to the latest rc6 this morning it seems to be working with setting the mask on probe. I am still testing out and will appreciate any idea what may cause the nvme driver to fail with a single mask. -- Jianxiong Gao _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme 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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 B1875C433DB for ; Mon, 1 Feb 2021 21:23:01 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 23A4964E31 for ; Mon, 1 Feb 2021 21:23:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23A4964E31 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lists.linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id D40C785E12; Mon, 1 Feb 2021 21:23:00 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id IoUp-UbeShZQ; Mon, 1 Feb 2021 21:23:00 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 5913785CC7; Mon, 1 Feb 2021 21:23:00 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 485EFC0FA7; Mon, 1 Feb 2021 21:23:00 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id 9BFCBC013A for ; Mon, 1 Feb 2021 21:22:59 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 902CB857FB for ; Mon, 1 Feb 2021 21:22:59 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5DDd_oFKdCWv for ; Mon, 1 Feb 2021 21:22:59 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-oi1-f176.google.com (mail-oi1-f176.google.com [209.85.167.176]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 1648B85797 for ; Mon, 1 Feb 2021 21:22:59 +0000 (UTC) Received: by mail-oi1-f176.google.com with SMTP id d20so4661654oiw.10 for ; Mon, 01 Feb 2021 13:22:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yOWrw7a+Nf/KygeG78AKIm4KgYP1X9MsGHak8Pcn4zg=; b=o5jpmsDsoy2ji8gpSb36ZTjvFoA1b9ZgnxGP7BNO941bOozBAgb85HxfqP7ke9weQZ SpK7oyNLgUjJX2fDxDZQDiKj5OnmmA1iQLR9Pql9Y7kN07+suHgVlZpX849oC7jsFT57 cW0DfuuM2Hw+BuZiiWMrn3sKFp79qYjY1DUgakhu1dQ4GghBwUHxOdFyECtLgJOMYpS7 W8pMJq1aTdPk1qovkiZBrTCtatjVdjA9o1hN0/ieRYZ0JWHw8Q5D/5SEmXQsU5cXpIOn sy0df7yFz7oIgQHyrO6/mHCdDwFjmVgfsBhSFTnEzLu5c/U7EipCXJRYolPbbg8FIuOo 2P8A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yOWrw7a+Nf/KygeG78AKIm4KgYP1X9MsGHak8Pcn4zg=; b=p+al0DX+ZB7vbAzR1KTJJpTPDjkA99RuJZ+GRvCovOWLe/RXQxHVkIvmWpTdB1rd1s HI69egVWJ98N2jJOvuhwE0iMANjhsvUk7bZevkOXkI40sPw2W9NUTCrA65/SCXTlJrlU cOFyWgo4HnY1ipiQEDCHaNSgJjefr2I5DNMUbQrTUuXyQ+2hjGXvCdg3saIH3pyOt8II Sc1QHVP74wE4YaV6sM2SXde8/dJcxHqz2RDrxtPi/Pn1alYYullRolYWxaf1LzTv3NbE 5qUvNUcAVnU1ywLgs4138ha+cpkX2mwK5UPJUxTKAv7XEFAre6xGpEO67WylwHNxkzuJ afiw== X-Gm-Message-State: AOAM530Ivs0ggOXPGPzpsuCVEenbt4b79PlDBvTe1DNlIOLxVSz8MKyN mbPDdR1tAoKcB5IVHmhQwFf/DZT7zVBJgdvyedK7Ww== X-Google-Smtp-Source: ABdhPJwLLr7HE/FPtCzHw8vOCiRi6L3hhZDdCNDFos3jTHmz5rAH077nWm3ycDUwLoEjDXEKNGh/LvplLh9wMECNwRg= X-Received: by 2002:aca:be0b:: with SMTP id o11mr575501oif.42.1612214578188; Mon, 01 Feb 2021 13:22:58 -0800 (PST) MIME-Version: 1.0 References: <20210201183017.3339130-1-jxgao@google.com> <20210201183017.3339130-4-jxgao@google.com> <20210201205759.GA2128135@dhcp-10-100-145-180.wdc.com> In-Reply-To: Date: Mon, 1 Feb 2021 13:22:45 -0800 Message-ID: Subject: Re: [PATCH V2 3/3] Adding device_dma_parameters->offset_preserve_mask to NVMe driver. To: Keith Busch Cc: heikki.krogerus@linux.intel.com, sagi@grimberg.me, Saravana Kannan , Konrad Rzeszutek Wilk , Marc Orr , gregkh@linuxfoundation.org, rafael.j.wysocki@intel.com, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, axboe@fb.com, bgolaszewski@baylibre.com, iommu@lists.linux-foundation.org, jroedel@suse.de, dan.j.williams@intel.com, Andy Shevchenko , Robin Murphy , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Jianxiong Gao via iommu Reply-To: Jianxiong Gao Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" > Why is this setting being done and undone on each IO? Wouldn't it be > more efficient to set it once during device initialization? > > And more importantly, this isn't thread safe: one CPU may be setting the > device's dma alignment mask to 0 while another CPU is expecting it to be > NVME_CTRL_PAGE_SIZE - 1. I was having trouble getting the OS booted when setting it once during initialization. However when I rebased to the latest rc6 this morning it seems to be working with setting the mask on probe. I am still testing out and will appreciate any idea what may cause the nvme driver to fail with a single mask. -- Jianxiong Gao _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu