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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 9A33DC433E0 for ; Tue, 4 Aug 2020 20:31:42 +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 6DDEE206D8 for ; Tue, 4 Aug 2020 20:31:42 +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="MsVnTk5M" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DDEE206D8 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]:47282 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k33b3-00041o-F9 for qemu-devel@archiver.kernel.org; Tue, 04 Aug 2020 16:31:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55732) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k33Zu-0003MD-TI for qemu-devel@nongnu.org; Tue, 04 Aug 2020 16:30:31 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:23407 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k33Zr-00060O-S8 for qemu-devel@nongnu.org; Tue, 04 Aug 2020 16:30:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596573024; 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=a3VXSAPpUQQNgNCgJuKI0W1EKybMMe3BhH0aRrRNZ0A=; b=MsVnTk5MFhnIYa6FRWiZVmKT6CnkY2HB3o3sL5aPob/18+4GeN+rW9/wFkqmBbeV3AolsH wYWijPF3zGlHKV98GT7tThkPvlMAs9qHsYmNXmb5JjlUkREW3A/CTajfjmbeIT6PLg7+Fx aNVL+W29LvMEU55gRGYYy96mymUxi+4= Received: from mail-qv1-f69.google.com (mail-qv1-f69.google.com [209.85.219.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-98-1AdhPZXUMU2Goxa_oTLn2w-1; Tue, 04 Aug 2020 16:30:21 -0400 X-MC-Unique: 1AdhPZXUMU2Goxa_oTLn2w-1 Received: by mail-qv1-f69.google.com with SMTP id z10so6074105qvm.0 for ; Tue, 04 Aug 2020 13:30:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=a3VXSAPpUQQNgNCgJuKI0W1EKybMMe3BhH0aRrRNZ0A=; b=Kf2w1yq06nJnVmK7h3paxe37kRW+fIHC0Y2TzCCFRshGdPGHd/ud1xtAH+CgByiemu uXS5aj9ovHm2gA0/VQdlhxMbcQ3GkhZYsjOs+XWV3zKML8S7hZSbAMuGZbH8lTCywYd0 QyA+wSYbdsBL/ZPir1DK+Q5xnYFdx3jypMdg/NRE6ixdFVzccyWdBtfK+qs5g7ZS8a4+ mLmaJGFz/YsEe+XN94UgicZ/ezXpzvecXDAiVcntVQ0P5UVakBxutg8g1su7WNv+EwXn gOys5XiTmECvXPKDnue+WAyDE4I+t6yoMArsV9AD8mJYGhbK80NtaGpPreead03ieq28 29Nw== X-Gm-Message-State: AOAM531LdihdqGNukhcTFjwewbZOH2AMsPH/bMTWjZ1mN5rS6NoezSSz oJ+A61HkGGVhP9h/QK4v8kT9fGKa2hTY/7YNYLQ6pZnCA/BWLN6KPtAwN8KcC94Tt9nOvhp2FJ0 4FZgzHG0QArf5DOc= X-Received: by 2002:ad4:5748:: with SMTP id q8mr116376qvx.217.1596573020614; Tue, 04 Aug 2020 13:30:20 -0700 (PDT) X-Google-Smtp-Source: ABdhPJz9VlU/xmlCxsLHeO/u3cc6UuJjSPjh86Q7xWy6XDRYQiU82STBzxf5e5IzQUwc/U01qnDGPQ== X-Received: by 2002:ad4:5748:: with SMTP id q8mr116354qvx.217.1596573020356; Tue, 04 Aug 2020 13:30:20 -0700 (PDT) Received: from xz-x1 (bras-vprn-toroon474qw-lp130-11-70-53-122-15.dsl.bell.ca. [70.53.122.15]) by smtp.gmail.com with ESMTPSA id x67sm24161112qke.136.2020.08.04.13.30.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Aug 2020 13:30:19 -0700 (PDT) Date: Tue, 4 Aug 2020 16:30:18 -0400 From: Peter Xu To: Eugenio =?utf-8?B?UMOpcmV6?= Subject: Re: [RFC v2 1/1] memory: Delete assertion in memory_region_unregister_iommu_notifier Message-ID: <20200804203018.GD90726@xz-x1> References: <20200628144746.GA239443@xz-x1> <54d2cdfd-97b8-9e1d-a607-d7a5e96be3a1@redhat.com> <20200629133403.GA266532@xz-x1> <2589d0e9-cc5b-a4df-8790-189b49f1a40e@redhat.com> <20200630153911.GD3138@xz-x1> <69f6d6e7-a0b1-abae-894e-4e81b7e0cc90@redhat.com> <20200702154540.GI40675@xz-x1> <34fe0e55-c0ae-8e56-462b-6281b6cca4f5@redhat.com> <7c17ff0c1be07c3e490fb02abb2b39a1d9f269b8.camel@redhat.com> MIME-Version: 1.0 In-Reply-To: <7c17ff0c1be07c3e490fb02abb2b39a1d9f269b8.camel@redhat.com> Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.120; envelope-from=peterx@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/04 01:28:23 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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 , Yan Zhao , "Michael S. Tsirkin" , "libvir-list@redhat.com" , Jason Wang , Juan Quintela , qemu-devel@nongnu.org, Eric Auger , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Aug 03, 2020 at 06:00:34PM +0200, Eugenio Pérez wrote: > On Fri, 2020-07-03 at 15:24 +0800, Jason Wang wrote: > > On 2020/7/2 下午11:45, Peter Xu wrote: > > > On Thu, Jul 02, 2020 at 11:01:54AM +0800, Jason Wang wrote: > > > > So I think we agree that a new notifier is needed? > > > Good to me, or a new flag should be easier (IOMMU_NOTIFIER_DEV_IOTLB)? > > > > That should work but I wonder something as following is better. > > > > Instead of introducing new flags, how about carry the type of event in > > the notifier then the device (vhost) can choose the message it want to > > process like: > > > > static vhost_iommu_event(IOMMUNotifier *n, IOMMUTLBEvent *event) > > > > { > > > > switch (event->type) { > > > > case IOMMU_MAP: > > case IOMMU_UNMAP: > > case IOMMU_DEV_IOTLB_UNMAP: > > ... > > > > } > > > > Thanks > > > > > > Hi! > > Sorry, I thought I had this clear but now it seems not so clear to me. Do you mean to add that switch to the current > vhost_iommu_unmap_notify, and then the "type" field to the IOMMUTLBEntry? Is that the scope of the changes, or there is > something I'm missing? > > If that is correct, what is the advantage for vhost or other notifiers? I understand that move the IOMMUTLBEntry (addr, > len) -> (iova, mask) split/transformation to the different notifiers implementation could pollute them, but this is even a deeper change and vhost is not insterested in other events but IOMMU_UNMAP, isn't? > > On the other hand, who decide what type of event is? If I follow the backtrace of the assert in > https://lists.gnu.org/archive/html/qemu-devel/2020-07/msg01015.html, it seems to me that it should be > vtd_process_device_iotlb_desc. How do I know if it should be IOMMU_UNMAP or IOMMU_DEV_IOTLB_UNMAP? If I set it in some > function of memory.c, I should decide the type looking the actual notifier, isn't? (Since Jason didn't reply yesterday, I'll try to; Jason, feel free to correct me...) IMHO whether to put the type into the IOMMUTLBEntry is not important. The important change should be that we introduce IOMMU_DEV_IOTLB_UNMAP (or I'd rather call it IOMMU_DEV_IOTLB directly which is shorter and cleaner). With that information we can make the failing assertion conditional for MAP/UNMAP only. We can also allow dev-iotlb messages to take arbitrary addr_mask (so it becomes a length of address range; imho we can keep using addr_mask for simplicity, but we can comment for addr_mask that for dev-iotlb it can be not a real mask). Thanks, -- Peter Xu