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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 ECB19C04ABB for ; Tue, 11 Sep 2018 10:25:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACD7220839 for ; Tue, 11 Sep 2018 10:25:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ACD7220839 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727764AbeIKPXt (ORCPT ); Tue, 11 Sep 2018 11:23:49 -0400 Received: from mx2.suse.de ([195.135.220.15]:45552 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726916AbeIKPXs (ORCPT ); Tue, 11 Sep 2018 11:23:48 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3C780ACBA; Tue, 11 Sep 2018 10:25:07 +0000 (UTC) Date: Tue, 11 Sep 2018 12:25:04 +0200 From: Borislav Petkov To: Paolo Bonzini Cc: Brijesh Singh , Sean Christopherson , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Tom Lendacky , Thomas Gleixner , "H. Peter Anvin" , Radim =?utf-8?B?S3LEjW3DocWZ?= Subject: Re: [PATCH v6 5/5] x86/kvm: Avoid dynamic allocation of pvclock data when SEV is active Message-ID: <20180911102504.GC11418@zn.tnic> References: <20180910122727.GE21815@zn.tnic> <026d5ca5-7b77-de6c-477e-ff39f0291ac0@amd.com> <1536586152.11460.40.camel@intel.com> <097eb5f5-2cd9-8b08-32c5-d90c8e0cbb6d@amd.com> <1536593297.11460.72.camel@intel.com> <11618b8b-4d1f-9307-35f0-3c0f0fc856ca@amd.com> <20180910164851.GC20286@zn.tnic> <3b8b4c9c-b0f6-1e08-3d26-0e146cd7189e@redhat.com> <20180911100142.GA11418@zn.tnic> <554c6fb5-0de4-5415-9970-0d09325d718b@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <554c6fb5-0de4-5415-9970-0d09325d718b@redhat.com> User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 11, 2018 at 12:19:13PM +0200, Paolo Bonzini wrote: > That's exactly what kvmclock is for, it provides a stable and > synchronized clock on top of unsynchronized TSCs. But that's also why > you need one struct per vCPU, at least in the synchronized case. Why? Why can't it be a single pointer to a struct pvclock_vsyscall_time_info shared between all vCPUs? Or does each vCPU write its own specific stuff into it so it has to be per-vCPU? -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --