From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:58004) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hGJKm-0000Ms-9F for qemu-devel@nongnu.org; Tue, 16 Apr 2019 04:20:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hGJKk-0006RG-HQ for qemu-devel@nongnu.org; Tue, 16 Apr 2019 04:20:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40148) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hGJKk-0006Pz-8A for qemu-devel@nongnu.org; Tue, 16 Apr 2019 04:20:50 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8A1BCC05683E for ; Tue, 16 Apr 2019 08:20:48 +0000 (UTC) Date: Tue, 16 Apr 2019 09:20:45 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20190416082044.GA2788@work-vm> References: <20190411152520.10061-1-armbru@redhat.com> <20190411152520.10061-10-armbru@redhat.com> <20190415154342.GM2852@work-vm> <871s228ojv.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871s228ojv.fsf@dusky.pond.sub.org> Subject: Re: [Qemu-devel] [PATCH 09/17] target: Simplify how the TARGET_cpu_list() print List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: qemu-devel@nongnu.org * Markus Armbruster (armbru@redhat.com) wrote: > "Dr. David Alan Gilbert" writes: > > > * Markus Armbruster (armbru@redhat.com) wrote: > >> The various TARGET_cpu_list() take an fprintf()-like callback and a > >> FILE * to pass to it. Their callers (vl.c's main() via list_cpus(), > >> bsd-user/main.c's main(), linux-user/main.c's main()) all pass > >> fprintf() and stdout. Thus, the flexibility provided by the (rather > >> tiresome) indirection isn't actually used. > >> > >> Drop the callback, and call qemu_fprintf() instead. > > > > Actually calling qemu_printf > > Typo, will fix. Thanks! > > >> Calling printf() would also work, but would make the code unsuitable > >> for monitor context without making it simpler. > > > > Gernally OK; but just checking - are there any flag combos that will > > mean this ends up with the result going down a monitor rather than > > stdout, and will that upset something like libvirt that might be using > > this to enumerate a cpu list? > > No. > > qemu_printf() prints to current monitor if we have one, else to stdout. > Thus, it prints to stdout as long as !cur_mon. > > cur_mon is thread-local, and always set like this: > > Monitor *old_mon = cur_mon; > cur_mon = ... non-null value ... > ... do something ... > cur-mon = old_mon; > > It's set and restored > > * in monitor_qmp_dispatch() around executing a QMP command > > * in monitor_read() around handling HMP input (this includes executing > a command) > > * in qmp_human_monitor_command() around executing the HMP command (this > is where monitors become nested) > > Therefore, cur_mon is null unless we're executing a QMP command, an HMP > command, or are processing HMP input. > > Clearer now? Yes, thanks! Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK 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=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,T_HK_NAME_DR,USER_AGENT_MUTT 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 62D61C10F13 for ; Tue, 16 Apr 2019 08:21:59 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 332DE20821 for ; Tue, 16 Apr 2019 08:21:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 332DE20821 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 ([127.0.0.1]:32906 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hGJLq-0000ty-Gz for qemu-devel@archiver.kernel.org; Tue, 16 Apr 2019 04:21:58 -0400 Received: from eggs.gnu.org ([209.51.188.92]:58004) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hGJKm-0000Ms-9F for qemu-devel@nongnu.org; Tue, 16 Apr 2019 04:20:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hGJKk-0006RG-HQ for qemu-devel@nongnu.org; Tue, 16 Apr 2019 04:20:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40148) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hGJKk-0006Pz-8A for qemu-devel@nongnu.org; Tue, 16 Apr 2019 04:20:50 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8A1BCC05683E for ; Tue, 16 Apr 2019 08:20:48 +0000 (UTC) Received: from work-vm (ovpn-117-233.ams2.redhat.com [10.36.117.233]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D14135D707; Tue, 16 Apr 2019 08:20:47 +0000 (UTC) Date: Tue, 16 Apr 2019 09:20:45 +0100 From: "Dr. David Alan Gilbert" To: Markus Armbruster Message-ID: <20190416082044.GA2788@work-vm> References: <20190411152520.10061-1-armbru@redhat.com> <20190411152520.10061-10-armbru@redhat.com> <20190415154342.GM2852@work-vm> <871s228ojv.fsf@dusky.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <871s228ojv.fsf@dusky.pond.sub.org> User-Agent: Mutt/1.11.4 (2019-03-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Tue, 16 Apr 2019 08:20:48 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 09/17] target: Simplify how the TARGET_cpu_list() print X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190416082045.vb5BGG29QAh3w2lP0-kFf-xSpFyA3x4C1CG0Gzt39B4@z> * Markus Armbruster (armbru@redhat.com) wrote: > "Dr. David Alan Gilbert" writes: > > > * Markus Armbruster (armbru@redhat.com) wrote: > >> The various TARGET_cpu_list() take an fprintf()-like callback and a > >> FILE * to pass to it. Their callers (vl.c's main() via list_cpus(), > >> bsd-user/main.c's main(), linux-user/main.c's main()) all pass > >> fprintf() and stdout. Thus, the flexibility provided by the (rather > >> tiresome) indirection isn't actually used. > >> > >> Drop the callback, and call qemu_fprintf() instead. > > > > Actually calling qemu_printf > > Typo, will fix. Thanks! > > >> Calling printf() would also work, but would make the code unsuitable > >> for monitor context without making it simpler. > > > > Gernally OK; but just checking - are there any flag combos that will > > mean this ends up with the result going down a monitor rather than > > stdout, and will that upset something like libvirt that might be using > > this to enumerate a cpu list? > > No. > > qemu_printf() prints to current monitor if we have one, else to stdout. > Thus, it prints to stdout as long as !cur_mon. > > cur_mon is thread-local, and always set like this: > > Monitor *old_mon = cur_mon; > cur_mon = ... non-null value ... > ... do something ... > cur-mon = old_mon; > > It's set and restored > > * in monitor_qmp_dispatch() around executing a QMP command > > * in monitor_read() around handling HMP input (this includes executing > a command) > > * in qmp_human_monitor_command() around executing the HMP command (this > is where monitors become nested) > > Therefore, cur_mon is null unless we're executing a QMP command, an HMP > command, or are processing HMP input. > > Clearer now? Yes, thanks! Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK