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 394E5C43219 for ; Tue, 5 Apr 2022 22:40:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1390599AbiDEWe7 (ORCPT ); Tue, 5 Apr 2022 18:34:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1443055AbiDEPix (ORCPT ); Tue, 5 Apr 2022 11:38:53 -0400 Received: from smtp2.axis.com (smtp2.axis.com [195.60.68.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7F8F143C7C; Tue, 5 Apr 2022 06:54:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1649166856; x=1680702856; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=WhCHZK9GJJLMq21n9Wjs02V4Hy6iol3pV60QmFhYnXI=; b=jOu26AEgH52kLCEHGCDNClrCiuGQsqC0mMbV00LsCQ6D7yvqs5Dp0cZy optIlXUGOYK/V04EhtXgmp6AGk/51aFLQeuyzPywOKdv2JKXA+l+F6zE7 jxHOIV1w+04HJPidE7bujX1V1JGCLkwHL1iXL+GF9c51ejPvh7kJHrDJF sWsJXpEG7H3IcBsiHwqDNa1ca2VTQ5eAIIHcwcVTTvxCwHveoCzsrgoBD Qg4rKYHk/O7G0KuyvCJLe6mEPgEtYSv+lMmSdwpvvs1oz0dylwi73F+Ak 1fDOQjfbIzc4yDvOAyiXUKMXCl58iv6V6IbDYllLso+PQ6F552TycWKbq w==; Date: Tue, 5 Apr 2022 15:54:12 +0200 From: Vincent Whitchurch To: Johannes Berg CC: "linux-kernel@vger.kernel.org" , kernel , "devicetree@vger.kernel.org" , "linux-um@lists.infradead.org" , "shuah@kernel.org" , "brendanhiggins@google.com" , "linux-kselftest@vger.kernel.org" , "jic23@kernel.org" , "linux-iio@vger.kernel.org" , "lgirdwood@gmail.com" , "broonie@kernel.org" , "a.zummo@towertech.it" , "alexandre.belloni@bootlin.com" , "linux-rtc@vger.kernel.org" , "corbet@lwn.net" , "linux-doc@vger.kernel.org" Subject: Re: [RFC v1 01/10] roadtest: import libvhost-user from QEMU Message-ID: <20220405135412.GB28574@axis.com> References: <20220311162445.346685-1-vincent.whitchurch@axis.com> <20220311162445.346685-2-vincent.whitchurch@axis.com> <7f405d8d09a83954aa3411eff8b71ee687c7ec33.camel@sipsolutions.net> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <7f405d8d09a83954aa3411eff8b71ee687c7ec33.camel@sipsolutions.net> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Thu, Mar 24, 2022 at 02:00:10PM +0100, Johannes Berg wrote: > On Fri, 2022-03-11 at 17:24 +0100, Vincent Whitchurch wrote: > > Import the libvhost-user from QEMU for use in the implementation of the > > virtio devices in the roadtest backend. > > So hm, I wonder if this is the sensible thing to do? > > Not that I mind importing qemu code, but: > > 1) the implementation is rather complex in some places, and has support > for a LOT of virtio/vhost-user features that are really not needed > in these cases, for performance etc. It's also close to 4k LOC. Is this really a problem given that the code is imported as-is? The intention is not to have to make a lot of local modifications to it in the kernel tree. The code is stable and presumably well-tested upstream, and upstream maintains it as a separate library (in the QEMU source tree though) to encourage reuse. > 2) the implementation doesn't support time-travel mode which might come > in handy True, but I don't see the external time-travel controller stuff being too useful for the kinds of tests this framework is targeting.