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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id F37FFCD37B0 for ; Mon, 18 Sep 2023 15:16:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qiFxj-0000Qe-LU; Mon, 18 Sep 2023 11:14:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiFxi-0000QH-K4 for qemu-devel@nongnu.org; Mon, 18 Sep 2023 11:14:58 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiFxg-0001HD-KD for qemu-devel@nongnu.org; Mon, 18 Sep 2023 11:14:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695050095; 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:in-reply-to:in-reply-to: references:references; bh=mBi+GrP/fMicAK+eyLMmb1BmHNQhtP+f4qKX83WfSpQ=; b=TGpUB07uRH78LiV2iPJpcy4RRpoFvA8IgbkJIEbU5Aub3+d28xIBmQ8z0G+NgGFFL2b8bL UEW/Y8659JqEcDP2FCBbCYzYsnLAZfF2tth5avUlXan7GlAcDvIJvixs0nUS2sKVBxvnoE KerdSnf/PhyKOMH5D5oH/CglbuwKbeA= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-493-omWYfzXZN2SPx_BiUsdI-g-1; Mon, 18 Sep 2023 11:14:52 -0400 X-MC-Unique: omWYfzXZN2SPx_BiUsdI-g-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D4A233800BA5; Mon, 18 Sep 2023 15:14:51 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.114]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1EA1A170EC; Mon, 18 Sep 2023 15:14:50 +0000 (UTC) Date: Mon, 18 Sep 2023 16:14:47 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Daniel Xu Cc: kkostiuk@redhat.com, michael.roth@amd.com, qemu-devel@nongnu.org, hmodi@aviatrix.com Subject: Re: [PATCH 2/3] qga: Add optional stream-output argument to guest-exec Message-ID: References: <604ef5fd5bda8acdb837b5d28ec405e9fb0332a3.1695034158.git.dxu@dxuuu.xyz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <604ef5fd5bda8acdb837b5d28ec405e9fb0332a3.1695034158.git.dxu@dxuuu.xyz> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Sep 18, 2023 at 04:54:22AM -0600, Daniel Xu wrote: > Currently, commands run through guest-exec are "silent" until they > finish running. This is fine for short lived commands. But for commands > that take a while, this is a bad user experience. > > Usually long running programs know that they will run for a while. To > improve user experience, they will typically print some kind of status > to output at a regular interval. So that the user knows that their > command isn't just hanging. > > This commit adds support for an optional stream-output parameter to > guest-exec. This causes subsequent calls to guest-exec-status to return > all buffered output. This allows downstream applications to be able to > relay "status" to the end user. > > If stream-output is requested, it is up to the guest-exec-status caller > to keep track of the last seen output position and slice the returned > output appropriately. This is fairly trivial for a client to do. And it > is a more reliable design than having QGA internally keep track of > position -- for the cases that the caller "loses" a response. I can understand why you want this incremental output facility, but at the same time I wonder where we draw the line for QGA with users needing a real shell session instead. When there is a long lived command, then IMHO it is also likely that there will be a need to kill the background running command too. We quickly end up re-inventing a shell in QGA if we go down this route. With 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 :|