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,URIBL_BLOCKED,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 AAAFBC352A2 for ; Thu, 6 Feb 2020 19:22:36 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 520E6218AC for ; Thu, 6 Feb 2020 19:22:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 520E6218AC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C24644A5A6; Thu, 6 Feb 2020 14:22:35 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id euzRAePM2Un5; Thu, 6 Feb 2020 14:22:34 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C36754A531; Thu, 6 Feb 2020 14:22:34 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 0AD134A4CD for ; Thu, 6 Feb 2020 14:22:34 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0ItKqxPScYO3 for ; Thu, 6 Feb 2020 14:22:32 -0500 (EST) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 8D63E4A4A3 for ; Thu, 6 Feb 2020 14:22:32 -0500 (EST) X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Feb 2020 11:22:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,410,1574150400"; d="scan'208";a="232140746" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.202]) by orsmga003.jf.intel.com with ESMTP; 06 Feb 2020 11:22:30 -0800 Date: Thu, 6 Feb 2020 11:22:30 -0800 From: Sean Christopherson To: Peter Xu Subject: Re: [PATCH v5 14/19] KVM: Clean up local variable usage in __kvm_set_memory_region() Message-ID: <20200206192230.GE13067@linux.intel.com> References: <20200121223157.15263-1-sean.j.christopherson@intel.com> <20200121223157.15263-15-sean.j.christopherson@intel.com> <20200206190641.GA700495@xz-x1> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200206190641.GA700495@xz-x1> User-Agent: Mutt/1.5.24 (2015-08-30) Cc: Wanpeng Li , kvm@vger.kernel.org, David Hildenbrand , linux-mips@vger.kernel.org, Paul Mackerras , kvmarm@lists.cs.columbia.edu, Janosch Frank , Marc Zyngier , Joerg Roedel , Christian Borntraeger , kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jim Mattson , Cornelia Huck , linux-kernel@vger.kernel.org, Paolo Bonzini , Vitaly Kuznetsov , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Thu, Feb 06, 2020 at 02:06:41PM -0500, Peter Xu wrote: > On Tue, Jan 21, 2020 at 02:31:52PM -0800, Sean Christopherson wrote: > > [...] > > > @@ -1101,52 +1099,55 @@ int __kvm_set_memory_region(struct kvm *kvm, > > if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) > > return -EINVAL; > > > > - slot = id_to_memslot(__kvm_memslots(kvm, as_id), id); > > - base_gfn = mem->guest_phys_addr >> PAGE_SHIFT; > > - npages = mem->memory_size >> PAGE_SHIFT; > > - > > - if (npages > KVM_MEM_MAX_NR_PAGES) > > - return -EINVAL; > > - > > /* > > * Make a full copy of the old memslot, the pointer will become stale > > * when the memslots are re-sorted by update_memslots(). > > */ > > - old = *slot; > > + tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id); > > + old = *tmp; > > + tmp = NULL; > > Shall we keep this chunk to the patch where it will be used? Other > than that, it looks good to me. I assume you're talking about doing this instead of using @tmp? old = *id_to_memslot(__kvm_memslots(kvm, as_id), id); It's obviously possible, but I really like resulting diff for __kvm_set_memory_region() in "KVM: Terminate memslot walks via used_slots" when tmp is used. @@ -1104,8 +1203,13 @@ int __kvm_set_memory_region(struct kvm *kvm, * when the memslots are re-sorted by update_memslots(). */ tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id); - old = *tmp; - tmp = NULL; + if (tmp) { + old = *tmp; + tmp = NULL; + } else { + memset(&old, 0, sizeof(old)); + old.id = id; + } _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm