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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 169C5C05027 for ; Fri, 17 Feb 2023 16:38:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229999AbjBQQiN (ORCPT ); Fri, 17 Feb 2023 11:38:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50516 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229744AbjBQQiM (ORCPT ); Fri, 17 Feb 2023 11:38:12 -0500 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1F8410D2 for ; Fri, 17 Feb 2023 08:38:04 -0800 (PST) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4PJGyz6g9fz6J7R6; Sat, 18 Feb 2023 00:11:39 +0800 (CST) Received: from localhost (10.122.247.231) 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 15.1.2507.17; Fri, 17 Feb 2023 16:16:18 +0000 Date: Fri, 17 Feb 2023 16:16:17 +0000 From: Jonathan Cameron To: Jonathan Cameron via CC: Jonathan Cameron , Michael Tsirkin , Ben Widawsky , , , Ira Weiny , Gregory Price , Philippe =?ISO-8859-1?Q?Mathieu-Daud=E9?= , Mike Maslenkin Subject: Re: [PATCH 2/2] hw/cxl: Multi-Region CXL Type-3 Devices (Volatile and Persistent) Message-ID: <20230217161617.000064d1@huawei.com> In-Reply-To: <20230131163847.23025-3-Jonathan.Cameron@huawei.com> References: <20230131163847.23025-1-Jonathan.Cameron@huawei.com> <20230131163847.23025-3-Jonathan.Cameron@huawei.com> Organization: Huawei Technologies R&D (UK) Ltd. X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.29; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.122.247.231] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Tue, 31 Jan 2023 16:38:47 +0000 Jonathan Cameron via wrote: > From: Gregory Price > > This commit enables each CXL Type-3 device to contain one volatile > memory region and one persistent region. > > Two new properties have been added to cxl-type3 device initialization: > [volatile-memdev] and [persistent-memdev] > > The existing [memdev] property has been deprecated and will default the > memory region to a persistent memory region (although a user may assign > the region to a ram or file backed region). It cannot be used in > combination with the new [persistent-memdev] property. > > Partitioning volatile memory from persistent memory is not yet supported. > > Volatile memory is mapped at DPA(0x0), while Persistent memory is mapped > at DPA(vmem->size), per CXL Spec 8.2.9.8.2.0 - Get Partition Info. > > Signed-off-by: Gregory Price > Signed-off-by: Jonathan Cameron > Hi Gregory, I've added support for multiple HDM decoders and hence can now test both volatile and non volatile on same device. It very nearly all works. With one exception which is I couldn't poke the first byte of the non volatile region. I think we have an off by one in a single check. Interestingly it makes no difference when creating an FS on top (which was my standard test) so I only noticed when poking memory addresses directly to sanity check the HDM decoder setup. I'll roll a v2 if no one shouts out that I'm wrong. Note that adding multiple HDM decoders massively increases the number of test cases over what we had before to poke all the corners so I may well be missing stuff. Hopefully can send an RFC of that support out next week. Jonathan > -MemTxResult cxl_type3_read(PCIDevice *d, hwaddr host_addr, uint64_t *data, > - unsigned size, MemTxAttrs attrs) > +static int cxl_type3_hpa_to_as_and_dpa(CXLType3Dev *ct3d, > + hwaddr host_addr, > + unsigned int size, > + AddressSpace **as, > + uint64_t *dpa_offset) > { > - CXLType3Dev *ct3d = CXL_TYPE3(d); > - uint64_t dpa_offset; > - MemoryRegion *mr; > + MemoryRegion *vmr = NULL, *pmr = NULL; > > - /* TODO support volatile region */ > - mr = host_memory_backend_get_memory(ct3d->hostmem); > - if (!mr) { > - return MEMTX_ERROR; > + if (ct3d->hostvmem) { > + vmr = host_memory_backend_get_memory(ct3d->hostvmem); > + } > + if (ct3d->hostpmem) { > + pmr = host_memory_backend_get_memory(ct3d->hostpmem); > } > > - if (!cxl_type3_dpa(ct3d, host_addr, &dpa_offset)) { > - return MEMTX_ERROR; > + if (!vmr && !pmr) { > + return -ENODEV; > + } > + > + if (!cxl_type3_dpa(ct3d, host_addr, dpa_offset)) { > + return -EINVAL; > + } > + > + if (*dpa_offset > int128_get64(ct3d->cxl_dstate.mem_size)) { > + return -EINVAL; > + } > + > + if (vmr) { > + if (*dpa_offset <= int128_get64(vmr->size)) { Off by one I think. < > + *as = &ct3d->hostvmem_as; > + } else { > + *as = &ct3d->hostpmem_as; > + *dpa_offset -= vmr->size; > + } > + } else { > + *as = &ct3d->hostpmem_as; > } > > - if (dpa_offset > int128_get64(mr->size)) { > + return 0; > +}