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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 7BCE2C3F2D7 for ; Wed, 4 Mar 2020 22:04:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C83620716 for ; Wed, 4 Mar 2020 22:04:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388435AbgCDWEN (ORCPT ); Wed, 4 Mar 2020 17:04:13 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:46574 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728955AbgCDWEN (ORCPT ); Wed, 4 Mar 2020 17:04:13 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id C288715AD58E7; Wed, 4 Mar 2020 14:04:12 -0800 (PST) Date: Wed, 04 Mar 2020 14:04:10 -0800 (PST) Message-Id: <20200304.140410.731261448085906331.davem@davemloft.net> To: vithampi@vmware.com Cc: richardcochran@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Pv-drivers@vmware.com, virtualization@lists.linux-foundation.org, x86@kernel.org, thellstrom@vmware.com, jgross@suse.com Subject: Re: [PATCH RESEND] ptp: add VMware virtual PTP clock driver From: David Miller In-Reply-To: <20200228053230.GA457139@sc2-cpbu2-b0737.eng.vmware.com> References: <20200228053230.GA457139@sc2-cpbu2-b0737.eng.vmware.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Wed, 04 Mar 2020 14:04:13 -0800 (PST) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Vivek Thampi Date: Fri, 28 Feb 2020 05:32:46 +0000 > Add a PTP clock driver called ptp_vmw, for guests running on VMware ESXi > hypervisor. The driver attaches to a VMware virtual device called > "precision clock" that provides a mechanism for querying host system time. > Similar to existing virtual PTP clock drivers (e.g. ptp_kvm), ptp_vmw > utilizes the kernel's PTP hardware clock API to implement a clock device > that can be used as a reference in Chrony for synchronizing guest time with > host. > > The driver is only applicable to x86 guests running in VMware virtual > machines with precision clock virtual device present. It uses a VMware > specific hypercall mechanism to read time from the device. > > Reviewed-by: Thomas Hellstrom > Signed-off-by: Vivek Thampi > --- > Based on feedback, resending patch to include a broader audience. If it's just providing a read of an accurate timesource, I think it's kinda pointless to provide a full PTP driver for it.