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=-5.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 508E2C43331 for ; Thu, 26 Mar 2020 22:04:26 +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 1657E20719 for ; Thu, 26 Mar 2020 22:04:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=zededa.com header.i=@zededa.com header.b="FRT1gAJc" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1657E20719 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zededa.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHabG-00070d-TU; Thu, 26 Mar 2020 22:03:42 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHabE-00070Y-Ug for xen-devel@lists.xenproject.org; Thu, 26 Mar 2020 22:03:40 +0000 X-Inumbo-ID: a694f782-6fad-11ea-b34e-bc764e2007e4 Received: from mail-qt1-x844.google.com (unknown [2607:f8b0:4864:20::844]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id a694f782-6fad-11ea-b34e-bc764e2007e4; Thu, 26 Mar 2020 22:03:40 +0000 (UTC) Received: by mail-qt1-x844.google.com with SMTP id t17so6943085qtn.12 for ; Thu, 26 Mar 2020 15:03:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zededa.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=2ATbTVRNh9gXaku7ZuM3hIYbGx3eiFFd9YLrTG2izHs=; b=FRT1gAJc/5akzs10IOgcFJjyKYpFb7tZ9wcz/Iqhgab3L/0VgtEQnd24bq7hrcskPA hnNTUY5MJR9RCTdnhtzzgRAZqNIXL9ypVc08vUaAEo/G14XpX+ufLjJXH3jt0R3+Bvrx D6j/0VG1RIaGe0HpBNa6EKqFP9OuebqEo9TcOzxwwqT8Xw+jMuefM4G46N8qj4/9mZUR uPnDXWnvnw7TG9m7APWlaqN/y/srtF53WkwNNRdqE21bhZ3vm42VQWaOLMnZpfQtXqo1 cO4qJ9/Uc943hkfqzSEQwiIP67g9ebVzz00z3PZHadZY45t0YJOf0n1jnVEsXZlhjNzU fu/Q== 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:content-transfer-encoding; bh=2ATbTVRNh9gXaku7ZuM3hIYbGx3eiFFd9YLrTG2izHs=; b=pqWz4M6PkoaPsWC14roYC1cPHiMYNYvwWOekhAt8ORir3Filj2IVq/81q+kbI7ZAdD J496+PNcQgUXpkHPXJFI28mnF77ND4m0AlKCYajhUdv9HYU/mh0JHrPzV8hQGg2RVd3y uCBrLtDnXLaa5nDD8w8dT47VtVw7HFRz7byQSMwCVKAmM4lUJrR6nWq0fJDs4GqCTmpx 2IkL6CeAiDfaIgeNG1VdpzrIuyhtcWjORCBddL5bHBWOkRgKkWEMGmIN5VUyLrSEKE4q ybl4ZFIkz9x0Cl4/k2e+IqUpeBf4B9jxm6bxtxXj5bBPkcBjksb1ffJRDWQv6WaSxu7A zvYQ== X-Gm-Message-State: ANhLgQ0tEQxVs6BrzFV+0sUQ2SbGSm2Z2m+E3d3DAI66T8IWwSRIVOXe josqweo36+ZMNT1g31Eb/rtKPD6dNa+RFCi4mR9Djg== X-Google-Smtp-Source: ADFU+vvbQAJRnIofmi2uz38wx7ProZNxRPYc/6gP6ajugdFFiY2GvUzStv4GndA38tUoaBe+qA6gXegnFQyMsQiivj0= X-Received: by 2002:ac8:41cd:: with SMTP id o13mr11147788qtm.266.1585260219884; Thu, 26 Mar 2020 15:03:39 -0700 (PDT) MIME-Version: 1.0 References: <20200325110533.GC28601@Air-de-Roger> In-Reply-To: <20200325110533.GC28601@Air-de-Roger> From: Roman Shaposhnik Date: Thu, 26 Mar 2020 15:03:28 -0700 Message-ID: To: =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Xen-devel] PCIe IOMMU ACS support X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xenproject.org, Kevin Tian , Andrew Cooper , Jan Beulich , Paul Durrant Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Wed, Mar 25, 2020 at 4:05 AM Roger Pau Monn=C3=A9 = wrote: > > Adding the PCI and IOMMU maintainers. > > On Mon, Mar 23, 2020 at 01:55:01PM -0700, Roman Shaposhnik wrote: > > Hi! > > > > I was going through how Xen support PCIe IOMMU ACS and > > all I could find is this: > > https://github.com/xen-project/xen/blob/master/xen/drivers/passthro= ugh/pci.c#L608 > > which looks to me as an attempt of enabling ACS opportunistically, > > but still proceeding forward even if it fails. > > That's correct AFAICT. Xen will try to enable some features, but will > proceed normally if ACS is not available, or if some of the features > are not implemented. > > Are you looking to ensure that all devices on the system have a > certain feature enabled? My primary objective was to get some visibility into how Xen would prevent two PCIe devices behind a common bridge from doing p2p transactions (thus violating VM boundaries if those devices are assigned to different domains). It looks like Xen simply trusts the hardware. > Can you provide some more details about what you expect of ACS > handling? I was actually surprised not to see IOMMU groups in the style of what VFIO https://www.kernel.org/doc/Documentation/vfio.txt Thanks, Roman.