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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 74661C43331 for ; Fri, 6 Sep 2019 16:32:48 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 23841207FC for ; Fri, 6 Sep 2019 16:32:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23841207FC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AF96B6B0003; Fri, 6 Sep 2019 12:32:47 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AAB3A6B0005; Fri, 6 Sep 2019 12:32:47 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9E76A6B0006; Fri, 6 Sep 2019 12:32:47 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0073.hostedemail.com [216.40.44.73]) by kanga.kvack.org (Postfix) with ESMTP id 7DC326B0003 for ; Fri, 6 Sep 2019 12:32:47 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 0EF42181AC9AE for ; Fri, 6 Sep 2019 16:32:47 +0000 (UTC) X-FDA: 75905039574.23.can06_526ed731d0823 X-HE-Tag: can06_526ed731d0823 X-Filterd-Recvd-Size: 2236 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Fri, 6 Sep 2019 16:32:46 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 7402B68B20; Fri, 6 Sep 2019 18:32:41 +0200 (CEST) Date: Fri, 6 Sep 2019 18:32:41 +0200 From: Christoph Hellwig To: Bharata B Rao Cc: Christoph Hellwig , linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, linux-mm@kvack.org, paulus@au1.ibm.com, aneesh.kumar@linux.vnet.ibm.com, jglisse@redhat.com, linuxram@us.ibm.com, sukadev@linux.vnet.ibm.com, cclaudio@linux.ibm.com Subject: Re: [PATCH v7 1/7] kvmppc: Driver to manage pages of secure guest Message-ID: <20190906163241.GA12516@lst.de> References: <20190822102620.21897-1-bharata@linux.ibm.com> <20190822102620.21897-2-bharata@linux.ibm.com> <20190829083810.GA13039@lst.de> <20190830034259.GD31913@in.ibm.com> <20190902075356.GA28967@lst.de> <20190906113639.GA8748@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190906113639.GA8748@in.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Sep 06, 2019 at 05:06:39PM +0530, Bharata B Rao wrote: > > Also is bit 56+ a set of values, so is there 1 << 56 and 3 << 56 as well? Seems > > like even that other patch doesn't fully define these "pfn" values. > > I realized that the bit numbers have changed, it is no longer bits 60:56, > but instead top 8bits. > > #define KVMPPC_RMAP_UVMEM_PFN 0x0200000000000000 > static inline bool kvmppc_rmap_is_uvmem_pfn(unsigned long *rmap) > { > return ((*rmap & 0xff00000000000000) == KVMPPC_RMAP_UVMEM_PFN); > } In that overall scheme I'd actually much prefer something like (names just made up, they should vaguely match the spec this written to): static inline unsigned long kvmppc_rmap_type(unsigned long *rmap) { return (rmap & 0xff00000000000000); } And then where you check it you can use: if (kvmppc_rmap_type(*rmap) == KVMPPC_RMAP_UVMEM_PFN) and where you set it you do: *rmap |= KVMPPC_RMAP_UVMEM_PFN; as in the current patch to keep things symmetric.