From nobody Tue Feb 10 12:58:16 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1529027418924747.9406846925482; Thu, 14 Jun 2018 18:50:18 -0700 (PDT) Received: from localhost ([::1]:43832 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fTdsY-00054k-4r for importer@patchew.org; Thu, 14 Jun 2018 21:50:18 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47143) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fTdlw-0008TF-96 for qemu-devel@nongnu.org; Thu, 14 Jun 2018 21:43:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fTdlt-0003kh-5S for qemu-devel@nongnu.org; Thu, 14 Jun 2018 21:43:28 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59420 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fTdlt-0003k8-0a for qemu-devel@nongnu.org; Thu, 14 Jun 2018 21:43:25 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8A6A7818534C; Fri, 15 Jun 2018 01:43:24 +0000 (UTC) Received: from xz-mi.redhat.com (ovpn-12-17.pek2.redhat.com [10.72.12.17]) by smtp.corp.redhat.com (Postfix) with ESMTP id 49CD12023450; Fri, 15 Jun 2018 01:43:18 +0000 (UTC) From: Peter Xu To: qemu-devel@nongnu.org Date: Fri, 15 Jun 2018 09:42:47 +0800 Message-Id: <20180615014249.22730-5-peterx@redhat.com> In-Reply-To: <20180615014249.22730-1-peterx@redhat.com> References: <20180615014249.22730-1-peterx@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 15 Jun 2018 01:43:24 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 15 Jun 2018 01:43:24 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'peterx@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v3 4/6] docs: mention shared state protect for OOB 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: Kevin Wolf , Peter Maydell , Fam Zheng , Eric Auger , John Snow , peterx@redhat.com, Max Reitz , Christian Borntraeger , "Dr . David Alan Gilbert" , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Markus Armbruster Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Out-Of-Band handlers need to protect shared state if there is any. Mention it in the document. Suggested-by: Markus Armbruster Signed-off-by: Peter Xu --- docs/devel/qapi-code-gen.txt | 3 +++ 1 file changed, 3 insertions(+) diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt index 1366228b2a..bee9de35df 100644 --- a/docs/devel/qapi-code-gen.txt +++ b/docs/devel/qapi-code-gen.txt @@ -680,6 +680,9 @@ OOB command handlers must satisfy the following conditi= ons: - It does not invoke system calls that may block, - It does not access guest RAM that may block when userfaultfd is enabled for postcopy live migration. +- It needs to protect any shared state, since as long as a command + supports Out-Of-Band it means the handler can be run in parallel + with the same handler running in the other thread. =20 If in doubt, do not implement OOB execution support. =20 --=20 2.17.1