From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 5533F1FD9 for ; Mon, 23 Oct 2023 13:44:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32887E8 for ; Mon, 23 Oct 2023 06:44:28 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4SDbvb10m8z688Cb; Mon, 23 Oct 2023 21:41:47 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Mon, 23 Oct 2023 14:44:25 +0100 Date: Mon, 23 Oct 2023 14:44:24 +0100 From: Jonathan Cameron To: Ira Weiny CC: Ravi Kanth , Gregory Price , "linux-cxl@vger.kernel.org" , Sajjan Rao Subject: Re: Support for CXL v3.0 spec with QEMU Message-ID: <20231023144424.000061f4@Huawei.com> In-Reply-To: <6532e53ed63b0_21a97294d@iweiny-mobl.notmuch> References: <20230823180323.000052d5@Huawei.com> <6532e53ed63b0_21a97294d@iweiny-mobl.notmuch> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; 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="utf-8" Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100006.china.huawei.com (7.191.160.224) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected On Fri, 20 Oct 2023 13:38:22 -0700 Ira Weiny wrote: > Ravi Kanth wrote: > > Hi Jonathan / Gregory, > > Just wanted to touch base on below questions and if you have any > > inputs on the same. Thanks for your help. > >=20 > > Thanks > > Ravi > >=20 > > On Wed, Oct 18, 2023 at 4:00=E2=80=AFPM Ravi Kanth wrote: =20 > > > > > > Hi Jonathan / Gregory, > > > > > > 1. Do we have the support in CXL driver to read the "Device status > > > registers" and specifically "Event status register" section 8.2.8.3 > > > and 8.2.8.3.1? =20 >=20 > Yes the upstream driver reads this when processing the Event interrupt > from the device. Then it uses the value to chose which logs to read. >=20 > See cxl_event_thread() in the kernel source. >=20 > > > 2. If an interrupt is posted by the device firmware, how will user > > > space applications be notified ? Do we have an interface for the same > > > in CXL driver? =20 >=20 > All events are reported through the trace infrastructure. >=20 > > > > > > If the above features are already supported in CXL driver, Can you > > > please point us to the sample code snippets to achieve the same? =20 >=20 > ndctl has the ability to monitor these events and example C code in there. >=20 > See .../cxl/event_trace.c in the ndctl project.[1] >=20 > [1] https://github.com/pmem/ndctl >=20 > > > > > > Also does the switch cci function change part of the mainline? =20 >=20 > I'm not sure I parse this question but I'm also not super familiar with > switch cci. So I'll let Jonathan answer this. Patches posted for review only at the moment - so 6.8 at earliest given tim= ing. https://lore.kernel.org/all/20231016125323.18318-1-Jonathan.Cameron@huawei.= com/ Main change to existing handling is that a bunch of mailbox related handlin= g is factored out for reuse. Otherwise, it's 'just another PCI endpoint driver'. Jonathan >=20 > Ira >=20 > > > > > > Thanks for your help in advance. > > > > > > Thanks > > > Ravi > > > =20 >=20 > [snip] >=20