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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 4FE1EC433E1 for ; Thu, 4 Jun 2020 23:03:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 292D8207DA for ; Thu, 4 Jun 2020 23:03:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="FsgtDi4P" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728109AbgFDXD5 (ORCPT ); Thu, 4 Jun 2020 19:03:57 -0400 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:37853 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726221AbgFDXD4 (ORCPT ); Thu, 4 Jun 2020 19:03:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1591311836; x=1622847836; h=date:from:to:cc:message-id:references:mime-version: in-reply-to:subject; bh=XlvjY2cbK79XKJQbABj6I52DuwNCmkoPmmNUgRZuzx4=; b=FsgtDi4Pv7uJuxVHUmYuYmjeDKtjri0bEhdXdULKxXlXZik0elc8l+1H Okxa5LoVs10W2+uh5dWu2Zf9V5m9t2BE0I58KYm4xTOcr/TBdkUTsGe8X xlus2sPLU/yRrLu7yrqqc7QwunL6zfIgt1D1iFB1k5N0GuJGFiMgyqMB0 I=; IronPort-SDR: BU/B31Mc2p1teKXE8T0M/Qekrk1iOuiIqPmHAVira61H+IDlK+H6BZmL2NxaskgX4guwfy+OUc I5F/nNdpGkaw== X-IronPort-AV: E=Sophos;i="5.73,472,1583193600"; d="scan'208";a="34541182" Subject: Re: [PATCH 03/12] x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1e-57e1d233.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 04 Jun 2020 23:03:43 +0000 Received: from EX13MTAUWC001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1e-57e1d233.us-east-1.amazon.com (Postfix) with ESMTPS id 7E52614194D; Thu, 4 Jun 2020 23:03:35 +0000 (UTC) Received: from EX13D05UWC001.ant.amazon.com (10.43.162.82) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 4 Jun 2020 23:03:07 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D05UWC001.ant.amazon.com (10.43.162.82) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 4 Jun 2020 23:03:07 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Thu, 4 Jun 2020 23:03:07 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 705A940712; Thu, 4 Jun 2020 23:03:07 +0000 (UTC) Date: Thu, 4 Jun 2020 23:03:07 +0000 From: Anchal Agarwal To: Boris Ostrovsky CC: , , , , , , , , , , , , , , , , , , , , , , , , , Message-ID: <20200604230307.GB25251@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> References: <529f544a64bb93b920bf86b1d3f86d93b0a4219b.1589926004.git.anchalag@amazon.com> <72989b50-0c13-7a2b-19e2-de4a3646c83f@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <72989b50-0c13-7a2b-19e2-de4a3646c83f@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 30, 2020 at 07:02:01PM -0400, Boris Ostrovsky wrote: > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you can confirm the sender and know the content is safe. > > > > On 5/19/20 7:25 PM, Anchal Agarwal wrote: > > Introduce a small function which re-uses shared page's PA allocated > > during guest initialization time in reserve_shared_info() and not > > allocate new page during resume flow. > > It also does the mapping of shared_info_page by calling > > xen_hvm_init_shared_info() to use the function. > > > > Signed-off-by: Anchal Agarwal > > --- > > arch/x86/xen/enlighten_hvm.c | 7 +++++++ > > arch/x86/xen/xen-ops.h | 1 + > > 2 files changed, 8 insertions(+) > > > > diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c > > index e138f7de52d2..75b1ec7a0fcd 100644 > > --- a/arch/x86/xen/enlighten_hvm.c > > +++ b/arch/x86/xen/enlighten_hvm.c > > @@ -27,6 +27,13 @@ > > > > static unsigned long shared_info_pfn; > > > > +void xen_hvm_map_shared_info(void) > > +{ > > + xen_hvm_init_shared_info(); > > + if (shared_info_pfn) > > + HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); > > +} > > + > > > AFAICT it is only called once so I don't see a need for new routine. > > HYPERVISOR_shared_info can only be mapped in this scope without refactoring much of the code. > And is it possible for shared_info_pfn to be NULL in resume path (which > is where this is called)? > > I don't think it should be, still a sanity check but I don't think its needed there because hibernation will fail in any case if thats the case. However, HYPERVISOR_shared_info does needs to be re-mapped on resume as its been marked to dummy address on suspend. Its also safe in case va changes. Does the answer your question? > -boris -Anchal > >