Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932087AbdI0OSl (ORCPT ); Wed, 27 Sep 2017 10:18:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:47773 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753111AbdI0OSk (ORCPT ); Wed, 27 Sep 2017 10:18:40 -0400 Subject: Re: [PATCH v4 2/3] x86/xen/time: setup vcpu 0 time info page To: Joao Martins , linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Boris Ostrovsky , Andy Lutomirski References: <20170927134623.3147-1-joao.m.martins@oracle.com> <20170927134623.3147-3-joao.m.martins@oracle.com> From: Juergen Gross Message-ID: Date: Wed, 27 Sep 2017 16:18:36 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20170927134623.3147-3-joao.m.martins@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 790 Lines: 19 On 27/09/17 15:46, Joao Martins wrote: > In order to support pvclock vdso on xen we need to setup the time > info page for vcpu 0 and register the page with Xen using the > VCPUOP_register_vcpu_time_memory_area hypercall. This hypercall > will also forcefully update the pvti which will set some of the > necessary flags for vdso. Afterwards we check if it supports the > PVCLOCK_TSC_STABLE_BIT flag which is mandatory for having > vdso/vsyscall support. And if so, it will set the cpu 0 pvti that > will be later on used when mapping the vdso image. > > The xen headers are also updated to include the new hypercall for > registering the secondary vcpu_time_info struct. > > Signed-off-by: Joao Martins Reviewed-by: Juergen Gross Juergen