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 69EBAD4A609 for ; Fri, 16 Jan 2026 08:19:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vgf2m-0005eq-0U; Fri, 16 Jan 2026 03:18:56 -0500 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 1vgf2j-0005eI-1N for qemu-devel@nongnu.org; Fri, 16 Jan 2026 03:18:53 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vgf2h-0000br-D5 for qemu-devel@nongnu.org; Fri, 16 Jan 2026 03:18:52 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768551529; h=from:from: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=LXjZInSASzu85EOJxxobjMLlRd3oJlKMDpWKPe31mVo=; b=A4XSCBrqCfhmp0feUxi3qUBuIHg7dkjqvgQ0O5qUdJ6w1Z1PtH1TU5nuGUHRj6l4ZZ+m6e mqUbG+/z9haaNwtyGsmEiehoUBab9X+Nb8e834rlj/Nn8uYFDaAeLAYrFPLRE3KVw/s2k4 FijN9e1lSn7ZM93flJWOtdJEx0ZjDe4= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-120-ZSZyNQdSMmi9ooVjG_5bZw-1; Fri, 16 Jan 2026 03:18:48 -0500 X-MC-Unique: ZSZyNQdSMmi9ooVjG_5bZw-1 X-Mimecast-MFC-AGG-ID: ZSZyNQdSMmi9ooVjG_5bZw_1768551527 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 093C51800357; Fri, 16 Jan 2026 08:18:47 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.45.242.32]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1C9643001DBA; Fri, 16 Jan 2026 08:18:46 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id C05D221E692D; Fri, 16 Jan 2026 09:18:43 +0100 (CET) From: Markus Armbruster To: Zhang Chen Cc: qemu-devel , "Dr . David Alan Gilbert" , Eric Blake Subject: Re: [PATCH 3/3] qapi: Add thread_status flag for iothreads In-Reply-To: (Zhang Chen's message of "Fri, 9 Jan 2026 11:11:27 +0800") References: <20251229103859.98777-1-zhangckid@gmail.com> <20251229103859.98777-3-zhangckid@gmail.com> <877bts8fsa.fsf@pond.sub.org> Date: Fri, 16 Jan 2026 09:18:43 +0100 Message-ID: <87wm1irmvw.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=armbru@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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Zhang Chen writes: > On Thu, Jan 8, 2026 at 8:12=E2=80=AFPM Markus Armbruster wrote: >> >> Zhang Chen writes: >> >> > The thread_status depends on struct IOThreadInfo's >> > 'attached': 'bool'. Show in the qmp/hmp CMD with >> > 'attached' or 'detached'. >> > >> > Signed-off-by: Zhang Chen >> > --- >> > iothread.c | 1 + >> > monitor/hmp-cmds.c | 2 ++ >> > qapi/misc.json | 6 ++++++ >> > 3 files changed, 9 insertions(+) >> > >> > diff --git a/iothread.c b/iothread.c >> > index 38e38fb44d..fb4898e491 100644 >> > --- a/iothread.c >> > +++ b/iothread.c >> > @@ -358,6 +358,7 @@ static int query_one_iothread(Object *object, void= *opaque) >> > info =3D g_new0(IOThreadInfo, 1); >> > info->id =3D iothread_get_id(iothread); >> > info->thread_id =3D iothread->thread_id; >> > + info->attached =3D iothread->attached; >> > info->poll_max_ns =3D iothread->poll_max_ns; >> > info->poll_grow =3D iothread->poll_grow; >> > info->poll_shrink =3D iothread->poll_shrink; >> > diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c >> > index 33a88ce205..84b01737cf 100644 >> > --- a/monitor/hmp-cmds.c >> > +++ b/monitor/hmp-cmds.c >> > @@ -197,6 +197,8 @@ void hmp_info_iothreads(Monitor *mon, const QDict = *qdict) >> > value =3D info->value; >> > monitor_printf(mon, "%s:\n", value->id); >> > monitor_printf(mon, " thread_id=3D%" PRId64 "\n", value->thr= ead_id); >> > + monitor_printf(mon, " thread_status=3D%s" "\n", >> > + value->attached ? "attached" : "detached"); >> > monitor_printf(mon, " poll-max-ns=3D%" PRId64 "\n", value->p= oll_max_ns); >> > monitor_printf(mon, " poll-grow=3D%" PRId64 "\n", value->pol= l_grow); >> > monitor_printf(mon, " poll-shrink=3D%" PRId64 "\n", value->p= oll_shrink); >> > diff --git a/qapi/misc.json b/qapi/misc.json >> > index 6153ed3d04..2eea920bd2 100644 >> > --- a/qapi/misc.json >> > +++ b/qapi/misc.json >> > @@ -76,6 +76,9 @@ >> > # >> > # @thread-id: ID of the underlying host thread >> > # >> > +# @attached: flag to show current iothread attached status >> >> What does "attached status" actually mean? > > This flag means weather the "-object iothread" already been used by a > real device. > In hotplug scenario, user can add multiple "-object iothread" and > multiple devices (like virtio-blk). > When user hotunplug the devices can keep the iothreads as a thread > pool, following the new > hotplug devices can attach to the released iothread. Why would a management application or human user want to know this? The answer should lead us to better doc text. >> >> > +# (since 10.3.0) >> >> (since 12.0) > > OK. > >> >> > +# >> > # @poll-max-ns: maximum polling time in ns, 0 means polling is >> > # disabled (since 2.9) >> > # >> > @@ -93,6 +96,7 @@ >> > { 'struct': 'IOThreadInfo', >> > 'data': {'id': 'str', >> > 'thread-id': 'int', >> > + 'attached': 'bool', >> > 'poll-max-ns': 'int', >> > 'poll-grow': 'int', >> > 'poll-shrink': 'int', >> > @@ -118,6 +122,7 @@ >> > # { >> > # "id":"iothread0", >> > # "thread-id":3134, >> > +# 'thread_status':"attached", >> >> I believe this is actually >> >> "attached": true >> >> and ... > > No, I changed it here for readability: > >> > + monitor_printf(mon, " thread_status=3D%s" "\n", >> > + value->attached ? "attached" : "detached"); > > But if you think ""attached": true" is more direct way, I can change > it next version. The example in the doc comment shows QMP. Here's what I see in QMP: $ qemu-system-x86_64 -S -display none -qmp stdio -object iothread,id=3D= iot0 -name debug-threads=3Don {"QMP": {"version": {"qemu": {"micro": 50, "minor": 2, "major": 10}, "p= ackage": "v10.2.0-521-g05115811fa"}, "capabilities": ["oob"]}} {"execute": "qmp_capabilities", "arguments": {"enable": ["oob"]}} {"return": {}} {"execute": "query-iothreads"} {"return": [{"attached": false, "poll-shrink": 0, "thread-id": 4031494,= "aio-max-batch": 0, "poll-grow": 0, "poll-max-ns": 32768, "id": "iot0"}]} This shows "attached": false, not 'thread_status': "attached". The code you showed applies to HMP: $ qemu-system-x86_64 -S -display none -monitor stdio -object iothread,i= d=3Diot0 -name debug-threads=3Don QEMU 10.2.50 monitor - type 'help' for more information (qemu) info iothreads iot0: thread_id=3D4032011 thread_status=3Ddetached poll-max-ns=3D32768 poll-grow=3D0 poll-shrink=3D0 aio-max-batch=3D0 thread_status=3Ddetached might be slightly more readable than attached=3Dfalse, but it could also be confusing to people working with both HMP and QMP. I'd avoid the difference between the two. >> >> > # 'poll-max-ns':0, >> > # "poll-grow":0, >> > # "poll-shrink":0, >> > @@ -126,6 +131,7 @@ >> > # { >> > # "id":"iothread1", >> > # "thread-id":3135, >> > +# 'thread_status':"detached", >> >> "attached": false >> >> Recommend to create example output by running a test instead of making >> it up, because making it up likely screws it up :) > > Uh.... This output print is the real test in my machine, maybe you > missed the previous description. I can't see how QMP could possibly show 'thread_status':"detached:. > > Thanks > Chen > >> >> > # 'poll-max-ns':0, >> > # "poll-grow":0, >> > # "poll-shrink":0, >>