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