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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D13A3C4332F for ; Mon, 12 Dec 2022 21:28:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233268AbiLLV2D (ORCPT ); Mon, 12 Dec 2022 16:28:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233212AbiLLV14 (ORCPT ); Mon, 12 Dec 2022 16:27:56 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E87F11741A for ; Mon, 12 Dec 2022 13:26:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670880416; 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=ESzb52BjV28O9Vn0affkyljMBG0fZ0DdXYD2mD//kKk=; b=MzIU5E80SNVivInvXQiQWZPus/GGJ2mr3srny/KUTVdU95Yozn3jQqOjDkGheoLAucR5yU UN/DiiLaFuKRS7MbBn/G1dLvtwCt/CcT1LNNvH5wGYJkm3nxR6JXpMcaXR0w4yfj+5X6xk 5BkoUYhN/cqiQJDzCBuUKfQhCxdLrBU= Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-616-icvrY9odMnyoj0fTdF90vg-1; Mon, 12 Dec 2022 16:26:54 -0500 X-MC-Unique: icvrY9odMnyoj0fTdF90vg-1 Received: by mail-il1-f198.google.com with SMTP id x9-20020a056e021ca900b003037ca1af0cso6085491ill.16 for ; Mon, 12 Dec 2022 13:26:54 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=ESzb52BjV28O9Vn0affkyljMBG0fZ0DdXYD2mD//kKk=; b=ZbQMJLgqmT0V1RJ/yK5xEo1ibhylB2o9iWgd/auL3x1LDXWsBCP4Nx+fGnAIycWQCj mEv3Stbq33R7M1sGWDjdrVvacfVuQ+2TSlqJyv3Iej6zs3rRe8Jq+g7FXnvL9PkXsJ+P TsKNNRt7WWgL3d/jB4VTc3LUpipXCakuV25D6HeEljMNckzwHRZx0BYLa0547AKtxEik Z+QOSrwV3rtS2DnxxLj9/H/ZIJwzfWiJljbMzZ/Q4hgODnEDM7FLC8gP96TSaTBuDr+U fWJ5e/pPyeiLEt6cCJheV69v8OWFvhFi0Ch76/hjl2UwOGUjOUFecDM3GfyvUbEGS6N8 UV8A== X-Gm-Message-State: ANoB5pk02Od6tY/KZSn1/Vymd/YCwl/f2HAn0BUzrD6tt5GMCGfIgXCd C6fDQdEq4ouBPxZmjgI+2peVSY20w22iMSnKtBFgx88+yrrhZ9avKJy2Fqb0SImjrUjS7brxX6w j5LRBSZYz6vaY X-Received: by 2002:a05:6602:1d4:b0:6df:e4f7:8c20 with SMTP id w20-20020a05660201d400b006dfe4f78c20mr9833123iot.14.1670880414009; Mon, 12 Dec 2022 13:26:54 -0800 (PST) X-Google-Smtp-Source: AA0mqf7v6Ul6nwS26XZd/iOTb8ZkMEzRCGY9PUjpxPpUAioVUp3lRXGnXSwiAa+CdB0kjNlvAEGgCA== X-Received: by 2002:a05:6602:1d4:b0:6df:e4f7:8c20 with SMTP id w20-20020a05660201d400b006dfe4f78c20mr9833118iot.14.1670880413778; Mon, 12 Dec 2022 13:26:53 -0800 (PST) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id i189-20020a6bb8c6000000b006dfb7d199dasm4506948iof.7.2022.12.12.13.26.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Dec 2022 13:26:53 -0800 (PST) Date: Mon, 12 Dec 2022 14:26:51 -0700 From: Alex Williamson To: Steven Sistare Cc: Jason Gunthorpe , "Tian, Kevin" , "kvm@vger.kernel.org" Subject: Re: [PATCH] vfio/type1: Cleanup remaining vaddr removal/update fragments Message-ID: <20221212142651.263dd6ae.alex.williamson@redhat.com> In-Reply-To: <8f29aad0-7378-ef7a-9ac5-f98b3054d5eb@oracle.com> References: <167044909523.3885870.619291306425395938.stgit@omen> <20221208094008.1b79dd59.alex.williamson@redhat.com> <20221209124212.672b7a9c.alex.williamson@redhat.com> <5f494e1f-536d-7225-e2c7-5ec9c993f13a@oracle.com> <20221209140120.667cb658.alex.williamson@redhat.com> <6914b4eb-cd82-0c3e-6637-c7922092ef11@oracle.com> <20221212085823.5d760656.alex.williamson@redhat.com> <8f29aad0-7378-ef7a-9ac5-f98b3054d5eb@oracle.com> X-Mailer: Claws Mail 4.1.0 (GTK 3.24.34; 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: kvm@vger.kernel.org On Mon, 12 Dec 2022 15:59:11 -0500 Steven Sistare wrote: > On 12/12/2022 10:58 AM, Alex Williamson wrote: > > On Mon, 12 Dec 2022 09:17:54 -0400 > > Jason Gunthorpe wrote: > > > >> On Sat, Dec 10, 2022 at 09:14:06AM -0500, Steven Sistare wrote: > >> > >>> Thank you for your thoughtful response. Rather than debate the degree of > >>> of vulnerability, I propose an alternate solution. The technical crux of > >>> the matter is support for mediated devices. > >> > >> I'm not sure I'm convinced about that. It is easy to make problematic > >> situations with mdevs, but that doesn't mean other cases don't exist > >> too eg what happens if userspace suspends and then immediately does > >> something to trigger a domain attachment? Doesn't it still deadlock > >> the kernel? > > > > The opportunity for that to deadlock isn't obvious to me, a replay > > would be stalled waiting for invalid vaddrs, but this is essentially > > the user deadlocking themselves. There's also code there to handle the > > process getting killed while waiting, making it interruptible. Thanks, > > I will submit new patches tomorrow to exclude mdevs. Almost done. I've dropped the removal commits from my next branch in the interim. Thanks, Alex