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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 D8A9AC43603 for ; Tue, 17 Dec 2019 20:41:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B36892467E for ; Tue, 17 Dec 2019 20:41:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728672AbfLQUlG (ORCPT ); Tue, 17 Dec 2019 15:41:06 -0500 Received: from mga07.intel.com ([134.134.136.100]:63055 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728519AbfLQUkq (ORCPT ); Tue, 17 Dec 2019 15:40:46 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Dec 2019 12:40:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,326,1571727600"; d="scan'208";a="389952615" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.202]) by orsmga005.jf.intel.com with ESMTP; 17 Dec 2019 12:40:43 -0800 From: Sean Christopherson To: James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini , Marc Zyngier Cc: David Hildenbrand , Cornelia Huck , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , James Morse , Julien Thierry , Suzuki K Poulose , linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, Christoffer Dall , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Subject: [PATCH v4 14/19] KVM: Clean up local variable usage in __kvm_set_memory_region() Date: Tue, 17 Dec 2019 12:40:36 -0800 Message-Id: <20191217204041.10815-15-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191217204041.10815-1-sean.j.christopherson@intel.com> References: <20191217204041.10815-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Clean up __kvm_set_memory_region() to achieve several goals: - Remove local variables that serve no real purpose - Improve the readability of the code - Better show the relationship between the 'old' and 'new' memslot - Prepare for dynamically sizing memslots. Note, using 'tmp' to hold the initial memslot is not strictly necessary at this juncture, e.g. 'old' could be directly copied from id_to_memslot(), but keep the pointer usage as id_to_memslot() will be able to return a NULL pointer once memslots are dynamically sized. Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 47 +++++++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 23 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2fa40c3e7961..b3e732078ab2 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1074,13 +1074,11 @@ static int kvm_delete_memslot(struct kvm *kvm, int __kvm_set_memory_region(struct kvm *kvm, const struct kvm_userspace_memory_region *mem) { - int r; - gfn_t base_gfn; - unsigned long npages; - struct kvm_memory_slot *slot; struct kvm_memory_slot old, new; - int as_id, id; + struct kvm_memory_slot *tmp; enum kvm_mr_change change; + int as_id, id; + int r; r = check_memory_region_flags(mem); if (r) @@ -1105,52 +1103,55 @@ 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; + if (!mem->memory_size) return kvm_delete_memslot(kvm, mem, &old, as_id); - new = old; - new.id = id; - new.base_gfn = base_gfn; - new.npages = npages; + new.base_gfn = mem->guest_phys_addr >> PAGE_SHIFT; + new.npages = mem->memory_size >> PAGE_SHIFT; new.flags = mem->flags; new.userspace_addr = mem->userspace_addr; + if (new.npages > KVM_MEM_MAX_NR_PAGES) + return -EINVAL; + if (!old.npages) { change = KVM_MR_CREATE; + new.dirty_bitmap = NULL; + memset(&new.arch, 0, sizeof(new.arch)); } else { /* Modify an existing slot. */ if ((new.userspace_addr != old.userspace_addr) || - (npages != old.npages) || + (new.npages != old.npages) || ((new.flags ^ old.flags) & KVM_MEM_READONLY)) return -EINVAL; - if (base_gfn != old.base_gfn) + if (new.base_gfn != old.base_gfn) change = KVM_MR_MOVE; else if (new.flags != old.flags) change = KVM_MR_FLAGS_ONLY; else /* Nothing to change. */ return 0; + + /* Copy dirty_bitmap and arch from the current memslot. */ + new.dirty_bitmap = old.dirty_bitmap; + memcpy(&new.arch, &old.arch, sizeof(new.arch)); } if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { /* Check for overlaps */ - kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) { - if (slot->id == id) + kvm_for_each_memslot(tmp, __kvm_memslots(kvm, as_id)) { + if (tmp->id == id) continue; - if (!((base_gfn + npages <= slot->base_gfn) || - (base_gfn >= slot->base_gfn + slot->npages))) + if (!((new.base_gfn + new.npages <= tmp->base_gfn) || + (new.base_gfn >= tmp->base_gfn + tmp->npages))) return -EEXIST; } } -- 2.24.1