Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753326AbdHJTI1 (ORCPT ); Thu, 10 Aug 2017 15:08:27 -0400 Received: from mail-dm3nam03on0130.outbound.protection.outlook.com ([104.47.41.130]:60192 "EHLO NAM03-DM3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753232AbdHJTIZ (ORCPT ); Thu, 10 Aug 2017 15:08:25 -0400 From: Jork Loeser To: KY Srinivasan , Peter Zijlstra , Simon Xiao , Haiyang Zhang , Stephen Hemminger , "torvalds@linux-foundation.org" , "luto@kernel.org" , "hpa@zytor.com" , "vkuznets@redhat.com" , "linux-kernel@vger.kernel.org" , "rostedt@goodmis.org" , "andy.shevchenko@gmail.com" , "tglx@linutronix.de" , "mingo@kernel.org" CC: "linux-tip-commits@vger.kernel.org" Subject: RE: [tip:x86/platform] x86/hyper-v: Use hypercall for remote TLB flush Thread-Topic: [tip:x86/platform] x86/hyper-v: Use hypercall for remote TLB flush Thread-Index: AQHTEgYxsK2uGstlkkue6l5rqOBtoqJ98McAgAAAr4CAAAHF0A== Date: Thu, 10 Aug 2017 19:08:22 +0000 Message-ID: References: <20170802160921.21791-8-vkuznets@redhat.com> <20170810185646.GI6524@worktop.programming.kicks-ass.net> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: msip_labels: MSIP_Label_f42aa342-8706-4288-bd11-ebb85995028c_Enabled=True; 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spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-originalarrivaltime: 10 Aug 2017 19:08:22.2175 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR21MB0696 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v7AJ8XaB007368 Content-Length: 1313 Lines: 35 > -----Original Message----- > From: KY Srinivasan > > -----Original Message----- > > From: Peter Zijlstra [mailto:peterz@infradead.org] > > Sent: Thursday, August 10, 2017 11:57 AM > > To: Simon Xiao ; Haiyang Zhang > > ; Jork Loeser ; > > Stephen Hemminger ; torvalds@linux- > > foundation.org; luto@kernel.org; hpa@zytor.com; vkuznets@redhat.com; > > linux-kernel@vger.kernel.org; rostedt@goodmis.org; > > andy.shevchenko@gmail.com; tglx@linutronix.de; KY Srinivasan > > ; mingo@kernel.org > > Cc: linux-tip-commits@vger.kernel.org > > Subject: Re: [tip:x86/platform] x86/hyper-v: Use hypercall for remote > > TLB flush > > Hold on.. if we don't IPI for TLB invalidation. What serializes our > > software page table walkers like fast_gup() ? > > Hypervisor may implement this functionality via an IPI. > > K. Y HvFlushVirtualAddressList() states: This call guarantees that by the time control returns back to the caller, the observable effects of all flushes on the specified virtual processors have occurred. HvFlushVirtualAddressListEx() refers to HvFlushVirtualAddressList() as adding sparse target VP lists. Is this enough of a guarantee, or do you see other races? Regards, Jork