From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-99.freemail.mail.aliyun.com (out30-99.freemail.mail.aliyun.com [115.124.30.99]) (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 ADE27641; Tue, 26 Dec 2023 02:30:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=wuzongyong@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0VzFsMjM_1703557804; Received: from localhost(mailfrom:wuzongyong@linux.alibaba.com fp:SMTPD_---0VzFsMjM_1703557804) by smtp.aliyun-inc.com; Tue, 26 Dec 2023 10:30:04 +0800 Date: Tue, 26 Dec 2023 10:30:04 +0800 From: Wu Zongyong To: alex.williamson@redhat.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, wutu.xq2@linux.alibaba.com Subject: [Question] Is it must for vfio-mdev parent driver to implement a pci-compliant configuration r/w interface Message-ID: Reply-To: Wu Zongyong Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi, For vfio, I know there are two method to get region size: 1. VFIO_DEVICE_GET_REGION_INFO ioctl 2. write a value of all 1's to the bar register of vfio-device fd and then read the value back which is described in pci spec Now I am curious about is it a must for a vfio-mdev parent driver to implement the method 2? Or it is just a optional interface. Thanks, Wu Zongyong