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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 35DF0CD4F3C for ; Tue, 19 May 2026 07:14:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=aq+bM6tjgMrDAzMW5P8tE4wGKZOZMJWYFdC9pcjM7u0=; b=a6MpSMHvvtzaXWeq4Obw3CYIse P6hTZA0aN4XmwzMFQOxlVN4B7StaMTA+kUdKstBy+kO20i6VfpITE98WRammfW2wwpoRRjvfHmeSA tJD2SqaYrAdZ2CX5oxucbcl4x3gL9A52ijCjYjTznQPBy3+jCxHFTnOXGa7DAJnFCNRhrBoNRML2i DFvb5mFQtJo1bb3k4RfZDCd2yPwYRyU4j6C2E47dZy844/HbMxs5IZNz7em6UvjsJQPBndGx8d2sq GLnt8urYC8FT3foZj7q2RyBgPfuB8mm1ZDWIdTdKg5/jqt8o5dvqNw2d4yUds4QmY0AQARnBfvEwP fviN/Crw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPEfI-00000000SDV-0NG4; Tue, 19 May 2026 07:14:56 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPEfF-00000000SBx-4B0d for linux-nvme@lists.infradead.org; Tue, 19 May 2026 07:14:55 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 5A6DE68C4E; Tue, 19 May 2026 09:14:49 +0200 (CEST) Date: Tue, 19 May 2026 09:14:48 +0200 From: Christoph Hellwig To: Chao Shi Cc: linux-nvme@lists.infradead.org, Keith Busch , Christoph Hellwig , Sagi Grimberg , Jens Axboe , Tatsuya Sasaki , Maurizio Lombardi , linux-kernel@vger.kernel.org, Sungwoo Kim , Dave Tian , Weidong Zhu Subject: Re: [PATCH v2] nvme: reserve a keep-alive admin tag for all transports Message-ID: <20260519071448.GA9841@lst.de> References: <20260515071248.2689513-1-coshi036@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260515071248.2689513-1-coshi036@gmail.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260519_001454_175737_4CFB7448 X-CRM114-Status: GOOD ( 13.80 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Fri, May 15, 2026 at 03:12:48AM -0400, Chao Shi wrote: > A quirk-based approach was considered but no PCIe controller > documented to declare KAS != 0 was found (two enterprise SSDs tested > locally report KAS=0), so an allowlist has no entries today. Quirking for spec allowed behavior sounds odd. If we care about testing KA for PCIe it should be trivial to implement in nvmet-epf in the kernel, but I'm not sure there is much of a point in that. > Reproducer (run as root on an unpatched kernel with a PCIe NVMe device): Can you wire this up as a testcase in blktests? The patch itself looks good: Reviewed-by: Christoph Hellwig