From nobody Sun Sep 28 16:28:09 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1756310964; cv=none; d=zohomail.com; s=zohoarc; b=YTeHLjeKm/q4DHi8FYXsnNXilSWushqaZJX3mhgz8elLvHs37O4M903d2umBl9e9aIKcegu9mxRXqOwd5eN/yJRwaYDg8cWRzKOiP8ZXAxHsWTMaexJTShxhsztUVr0qtAM/O/JvBf8N8r04VseNL3GzvD8UxEp2u4ZsNQArKzk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1756310964; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:Reply-To:Sender:Subject:Subject:To:To:Message-Id; bh=R7Pa9EjyLX/aMVPRIkDTyZJxKGGc1iuAsM5tlQA0b3Q=; b=KYoxqDr4qzM+zb62qHXk8+4h33in2A+BFXrSQ6qfVfFNZaD/TXCrew2d7xgsSyEIWAvCTpmvco/kfnk/1cAdl7J2bjYNIwXhRU2B+fOuFKWkygls2sZVzTbu/+ZkmbibumBkSURGwS+wOJit3bT86J79PaghgFgCsekpS5mrET0= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1756310964593587.3427941350128; Wed, 27 Aug 2025 09:09:24 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1urIhn-0005sh-LE; Wed, 27 Aug 2025 12:08:59 -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 1urIhl-0005rm-2Y for qemu-devel@nongnu.org; Wed, 27 Aug 2025 12:08:57 -0400 Received: from na1pdmzitismtp01.corp.cloud.com ([160.101.131.8] helo=na1pdmzitismtp01.tibco.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1urIhj-0007v6-BO for qemu-devel@nongnu.org; Wed, 27 Aug 2025 12:08:56 -0400 Received: from mewpvdipd1010.corp.cloud.com (unknown [10.113.40.46]) by na1pdmzitismtp01.tibco.com (Postfix) with ESMTP id 5B60C40D6683; Wed, 27 Aug 2025 12:08:14 -0400 (EDT) To: qemu-devel@nongnu.org, xen-devel@lists.xenproject.org Cc: sstabellini@kernel.org, anthony@xenproject.org, paul@xen.org, Mark Syms Subject: [PATCH] [xen-block] Return BLKIF_RSP_EOPNOTSUPP for unknown operation Date: Wed, 27 Aug 2025 17:08:41 +0100 Message-ID: <20250827160841.351707-1-mark.syms@cloud.com> X-Mailer: git-send-email 2.50.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=160.101.131.8; envelope-from=mark.syms@cloud.com; helo=na1pdmzitismtp01.tibco.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=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: Mark Syms From: Mark Syms via Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1756310966105124100 Content-Type: text/plain; charset="utf-8" Returning BLKIF_RSP_ERROR if an operation is not supoprted does not allow the frontend to exercise any discretion on how to handle the response and may lead to an operating system crash. As different backends may support different feature sets and we might, during a migration, switch backends, an in-flight request might be issued (or reissued) which is then not supported by this backend. Signed-off-by: Mark Syms --- hw/block/dataplane/xen-block.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c index 48c2e315f3..32cf919a97 100644 --- a/hw/block/dataplane/xen-block.c +++ b/hw/block/dataplane/xen-block.c @@ -167,7 +167,8 @@ static int xen_block_parse_request(XenBlockRequest *req= uest) return 0; default: error_report("error: unknown operation (%d)", request->req.operati= on); - goto err; + request->status =3D BLKIF_RSP_EOPNOTSUPP; + return -1; }; =20 if (request->req.operation !=3D BLKIF_OP_READ && --=20 2.50.1