From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F9AC149C64 for ; Fri, 13 Jun 2025 17:17:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749835062; cv=none; b=Z0c6s0gO6YZSVyxF+F/2enEW9jdLcI/EyNVhMTztVhFosFoUpIiB3qL2E9P1/UCqxIpJ17I1lPVktwQG6al9RWWg/4Npc6VU9FQ53D48iDNAATwPSqFxCm4+zFAoxcVtf9FtcvEv5a8Mng57JFtwJREsjRsev6JEvS7KybkCJec= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749835062; c=relaxed/simple; bh=OpH62wlamRZ82ZXATpFl4Y6yEBGJxZ7lzcqRt20TUcc=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=swS9Vk90LH6aWIffjoQ8bKpQLQYFy3bSgj6iObFZpt9uaj4EWxDN9Nmb28K4rHMx177FqM7DhZKcXE6jyVl0jkNmldVe5vT/vlWRePTHxexKjV7b9q8sob4Ziw54iSemW9h59dk7+bQWfkE0H0EvWVn9sGrLBK0Lyw65SCaD3cM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4bJmKf5XBnz6M4sr; Sat, 14 Jun 2025 01:17:10 +0800 (CST) Received: from frapeml500008.china.huawei.com (unknown [7.182.85.71]) by mail.maildlp.com (Postfix) with ESMTPS id 439BC140277; Sat, 14 Jun 2025 01:17:38 +0800 (CST) Received: from localhost (10.122.19.247) by frapeml500008.china.huawei.com (7.182.85.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 13 Jun 2025 19:17:37 +0200 Date: Fri, 13 Jun 2025 18:17:36 +0100 From: Jonathan Cameron To: Peter Maydell CC: , Fan Ni , , Zhijian Li , Itaru Kitayama , , , , Yuquan Wang , Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , Alireza Sanaee , Alex =?ISO-8859-1?Q?Benn=E9e?= Subject: Re: [PATCH v15 2/4] hw/cxl: Make the CXL fixed memory windows devices. Message-ID: <20250613181736.000063e5@huawei.com> In-Reply-To: References: <20250612134338.1871023-1-Jonathan.Cameron@huawei.com> <20250612134338.1871023-3-Jonathan.Cameron@huawei.com> <20250613140954.000013f5@huawei.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100006.china.huawei.com (7.191.160.224) To frapeml500008.china.huawei.com (7.182.85.71) On Fri, 13 Jun 2025 17:08:28 +0100 Peter Maydell wrote: > On Fri, 13 Jun 2025 at 14:10, Jonathan Cameron > wrote: > > For these specific devices (the fixed memory windows) there isn't > > any state as they are representing fixed configuration of the system. > > The state is all in the host bridges and beyond. I'll add > > a comment as you suggest. > > > > Currently CXL emulation is completely broken wrt to migration and > > there are some known issues for reset as well. Both are on the list > > of things to fix. Migration is less important as the only current use > > for this stuff is running software stack test cases and for that > > migration isn't currently of interest - that will change for some > > of the virtualization related work that is just getting started. > > That's OK as long as something somewhere is registering a > migration-blocker so there's a useful error message if the > user ever tries it. :( Michael asked for us to fix that a while back and I forgot. Will sort that out shortly. J > > -- PMM