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 X-Spam-Level: X-Spam-Status: No, score=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02459C2B9F4 for ; Tue, 22 Jun 2021 17:37:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAEE161353 for ; Tue, 22 Jun 2021 17:37:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232101AbhFVRj6 (ORCPT ); Tue, 22 Jun 2021 13:39:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229501AbhFVRj5 (ORCPT ); Tue, 22 Jun 2021 13:39:57 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1469DC061574 for ; Tue, 22 Jun 2021 10:37:40 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id d25so3197482lji.7 for ; Tue, 22 Jun 2021 10:37:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=9d2LZ9iaWzrwN5lQzvoZWRCYsnPkH1VeDq07zPhlLjU=; b=AivYEutHF7H6vNhI5DlcJIGt20nf4bbv9nA5BSZGG9Oh90hZb1P05OWmuuCaY5Q/bi KbFtIvEQQcC8o0HrDWYSIxAhX2akxIdjLkuWAEI0etMUNqp497U9A2EvMpS/qTMJvPwg mo19I8DkPDz6oXoIqGmTcZ7fIs28MtVpviTP0Exr2btOMadn3iArctfXvNMM7dXcJSe+ 1ecZfHR51IS34lqVk/v+6Lcgmj7JXY9uJUyWUG+f9CIDowfWo56ivPaDBe0OEuaQOwWr p1g/9VXnHe+A0O5gYDRhlRTN3wFZOESegbe5/ve04tdm9zscc4p+kkOTTKKxwhmCHe3K 5H9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=9d2LZ9iaWzrwN5lQzvoZWRCYsnPkH1VeDq07zPhlLjU=; b=NE4ek+JJw7ELJ/oZR/pvyaMQV13BzAc2HWRfkUASnu+52kb0TF7YHaqGQqgehv5Cy2 sTkTfjW5JwMuGAN+xqWqNLYeVds80QbZrNkvixwDrMAoGT/5snRwYEKo3JAf68pDEytV YkIwfEyNtmyr4zk0EzjiyPKV9BJY68fwF1ifisFWtG844DLvfTgAVGsKx0oXHMeoMGrV 3KKOwQda7OshBQgysB8C/bPufe3ReYF1xxQlF3rn8clY9zb8+C2PvV70F6NBWhsCfUnE tGh+CDBreQUtn7H/HdpMzuodQdgWdLXayVI/5CmxedJyzi5aITnsqrumkXTJHv2IuUje lukA== X-Gm-Message-State: AOAM532BxzNoJHHkaGHWteNOzV+Y2VTDvWYCK1MD2QpV0OgEnAwTrNJC yIbfsOGn3gEbQIc4nLtdOMHLEt4cT/4flvasrBI8XWSPzEVjJg== X-Google-Smtp-Source: ABdhPJwgEak4m2430LhmoQfRd9sv4h6O8b9wQfHoCeotYBMX1RrycxlQ3E1T45Jzt+xkfm8oim4Y1ZDyK3Mk86ATbF0= X-Received: by 2002:a2e:a722:: with SMTP id s34mr4188416lje.104.1624383458169; Tue, 22 Jun 2021 10:37:38 -0700 (PDT) MIME-Version: 1.0 From: samarth saxena Date: Tue, 22 Jun 2021 23:07:27 +0530 Message-ID: Subject: Question for CXL Drivers and ACPI required for a CXL mem device? To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi All, I am trying to bring up a system with a CXL Type 3 device using Qemu. I see that the device is visible in the operating system at the location: /dev/cxl/mem0 And a persistent memory attached to the device at /sys/bus/cxl/devices/mem0/pmem But I am unable to understand how to use this memory (pmem). How can the Linux map this Pmem instance to user space. Also, CXL device can be a non persistent memory too. How will that be visible? Which all drivers are necessary to use a CXL Type3 device as a memory expander? Is there any ongoing development in the kernel? Regards, Samarth