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=-10.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 4C674C433DB for ; Tue, 9 Mar 2021 10:40:33 +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 DF26564F20 for ; Tue, 9 Mar 2021 10:40:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF26564F20 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]:56754 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lJZmy-00013L-1y for qemu-devel@archiver.kernel.org; Tue, 09 Mar 2021 05:40:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:49780) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lJZfK-0002H5-2I for qemu-devel@nongnu.org; Tue, 09 Mar 2021 05:32:38 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:57103) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1lJZfH-0008CA-8s for qemu-devel@nongnu.org; Tue, 09 Mar 2021 05:32:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615285954; h=from:from:reply-to: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=CyUZNQe56qQ0ktupEIL2zPKRaaVLrQkmIgWjNkFJcfQ=; b=FoJ2fYs5TEX2j36krIv9T6s7Cg7CHQyecVpZcsHlhjMyxX9hlpjhVGxVKO8isdEs8ZxCoY KSMlto5wea6vrwg5hyj5hOYDN1r8EJmVeli8T/9veWN1gqQTzOi+tJfb75X1tmb6CtaLEi 93mWlYmkgDWlAvgltMGiuZoSjhwdNkk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-359-QTm8G_FaPYOJrYObN9YZjQ-1; Tue, 09 Mar 2021 05:32:31 -0500 X-MC-Unique: QTm8G_FaPYOJrYObN9YZjQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 20BEE108BD06; Tue, 9 Mar 2021 10:32:30 +0000 (UTC) Received: from redhat.com (ovpn-114-154.ams2.redhat.com [10.36.114.154]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1F85519709; Tue, 9 Mar 2021 10:32:24 +0000 (UTC) Date: Tue, 9 Mar 2021 10:32:22 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Maydell Subject: Re: [PATCH] coroutine: add libucontext as external library Message-ID: References: <20210309032637.41778-1-j@getutm.app> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.251, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Kevin Wolf , Paolo Bonzini , Joelle van Dyne , Stefan Hajnoczi , QEMU Developers Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Mar 09, 2021 at 10:20:07AM +0000, Peter Maydell wrote: > On Tue, 9 Mar 2021 at 09:59, Joelle van Dyne wrote: > > > > On Tue, Mar 9, 2021 at 1:36 AM Daniel P. Berrangé wrote: > > > The README here: > > > > > > https://github.com/kaniini/libucontext > > > > > > indicates that it is intentionally limiting what registers it saves > > > and restores, explicitly excluding FPU. > > > > > > Peter & Paolo expressed concern about this, indicating FPU reg support > > > was a requirement for QEMU: > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg05525.html > > > > > Does it make a difference if this is provided as an option and not as > > a replacement? Would it make sense to add some warning at configure > > time? Right now none of the concurrency backends are supported on iOS > > and it's possible support will go away on macOS as well in the future. > > QEMU would not be able to run at all. > > We don't currently support iOS; if we add it we definitely don't > want to add it as a "we know this has buggy coroutine support" > target, because that's a path to weird hard-to-diagnose bugs. If we consider the biggest coroutine user is the block layer, then "hard to diagnose bugs" may easily translate to "hard to disagnose data corruption of your guest disks", which is even worse. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|