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=-8.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 93C1EC432BE for ; Mon, 26 Jul 2021 23:28:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C44460F59 for ; Mon, 26 Jul 2021 23:28:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233954AbhGZWsJ (ORCPT ); Mon, 26 Jul 2021 18:48:09 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:50905 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233843AbhGZWsH (ORCPT ); Mon, 26 Jul 2021 18:48:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1627342114; 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=zGmsTgcyIKG5lma+qo/IbpdoduVKh2eYr03LqB0JH4c=; b=EhXz8GJZQn9Oxw2BBdNcRLXI3Z7Qfo8R/Eb4Cwnnw1SEtx0DG30a/b8PtEhs+j5JvHCTYK TqX3fkhg3nhcmzVYn5Oh7cJ3saWrQriNFcQD0fViGTSUzjh6tfZxH/hqZdcqChYCOPMpyM EykmwM1M73LbAujM6n+3MqtPcLooZew= Received: from mail-oo1-f70.google.com (mail-oo1-f70.google.com [209.85.161.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-168-8wy8naKYNFOr5IytlBUtMA-1; Mon, 26 Jul 2021 19:28:33 -0400 X-MC-Unique: 8wy8naKYNFOr5IytlBUtMA-1 Received: by mail-oo1-f70.google.com with SMTP id r15-20020a4aea8f0000b029025ec20a413eso7356159ooh.11 for ; Mon, 26 Jul 2021 16:28:33 -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:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=zGmsTgcyIKG5lma+qo/IbpdoduVKh2eYr03LqB0JH4c=; b=R0Hu6gAybJGw06ukQTwjYK2e1oAn9MxSRhIDSsjnij+Cs6lwmVljiadsr97wYAVHgG GYyhYCgIJ+mhg4kY8gTITD0elJvO9Gsrgy/x4m/jSK4huGkYZOHp6t0O5UA+kcnTJ6BM SMgFeIhzp237i/CYCLgxNhmjCkgfKPWeLVq2N3OzD6QZipn/e81wAMFUZTuNPgWdYi/G cwkIyDvvQpOhF50UWRYHsSuou0Rqt7kPHzf2Tc6RwbiR5uMFppgRgddInpEAGqeIXE1s iMzmiUZ22i1lgX7SVlYfYyYmhKpBJvscv4MDEZJef9ovsndWVEbiTGlu9zdBGUbP94sL AqCQ== X-Gm-Message-State: AOAM531CU6f/bOOopzlVPk85hUiSxtfFqGUJK9pbRi0CrkDjqlZ8yVBs wep+t+jJIICeMAdPNOHryGyrqxdHC7euszTtFLJpFRX32yGvsV+UFVnGqmppDdTnI5+7bkdIaQ1 1MIkxEOV4x7Nk6RfnwJRPrl+3 X-Received: by 2002:aca:a887:: with SMTP id r129mr1016705oie.128.1627342112662; Mon, 26 Jul 2021 16:28:32 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy3GADjIuORJLkoHf1pSPqO4kcuqx8II3jB98Pxdt6mv3Z6DUajXj/STasL7XqN3HL0GlGG5A== X-Received: by 2002:aca:a887:: with SMTP id r129mr1016693oie.128.1627342112452; Mon, 26 Jul 2021 16:28:32 -0700 (PDT) Received: from redhat.com ([198.99.80.109]) by smtp.gmail.com with ESMTPSA id p4sm219061ooa.35.2021.07.26.16.28.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jul 2021 16:28:32 -0700 (PDT) Date: Mon, 26 Jul 2021 17:28:31 -0600 From: Alex Williamson To: Jason Gunthorpe Cc: Cornelia Huck , Christoph Hellwig , Kirti Wankhede , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] vfio/mdev: don't warn if ->request is not set Message-ID: <20210726172831.3a7978fd.alex.williamson@redhat.com> In-Reply-To: <20210726230906.GD1721383@nvidia.com> References: <20210726143524.155779-1-hch@lst.de> <20210726143524.155779-3-hch@lst.de> <87zgu93sxz.fsf@redhat.com> <20210726230906.GD1721383@nvidia.com> Organization: Red Hat X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 26 Jul 2021 20:09:06 -0300 Jason Gunthorpe wrote: > On Mon, Jul 26, 2021 at 07:07:04PM +0200, Cornelia Huck wrote: > > > But I wonder why nobody else implements this? Lack of surprise removal? > > The only implementation triggers an eventfd that seems to be the same > eventfd as the interrupt.. > > Do you know how this works in userspace? I'm surprised that the > interrupt eventfd can trigger an observation that the kernel driver > wants to be unplugged? I think we're talking about ccw, but I see QEMU registering separate eventfds for each of the 3 IRQ indexes and the mdev driver specifically triggering the req_trigger...? Thanks, Alex