From patchwork Wed Jan 16 15:54:20 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 212638 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id F36312C0087 for ; Thu, 17 Jan 2013 03:02:09 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TvVRA-0001jS-Lc; Wed, 16 Jan 2013 16:02:00 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1TvVQQ-0001EL-12 for kernel-team@lists.ubuntu.com; Wed, 16 Jan 2013 16:01:14 +0000 Received: from [177.132.109.150] (helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1TvVQP-0006cD-Aw; Wed, 16 Jan 2013 16:01:13 +0000 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 060/222] KVM: Fix user memslot overlap check Date: Wed, 16 Jan 2013 13:54:20 -0200 Message-Id: <1358351822-7675-61-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> References: <1358351822-7675-1-git-send-email-herton.krzesinski@canonical.com> X-Extended-Stable: 3.5 Cc: Alex Williamson , Marcelo Tosatti X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com 3.5.7.3 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Alex Williamson commit 5419369ed6bd4cf711fdda5e52a5999b940413f5 upstream. Prior to memory slot sorting this loop compared all of the user memory slots for overlap with new entries. With memory slot sorting, we're just checking some number of entries in the array that may or may not be user slots. Instead, walk all the slots with kvm_for_each_memslot, which has the added benefit of terminating early when we hit the first empty slot, and skip comparison to private slots. Signed-off-by: Alex Williamson Signed-off-by: Marcelo Tosatti Signed-off-by: Herton Ronaldo Krzesinski --- virt/kvm/kvm_main.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 44ee712..7d9d969 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -689,8 +689,7 @@ int __kvm_set_memory_region(struct kvm *kvm, int r; gfn_t base_gfn; unsigned long npages; - unsigned long i; - struct kvm_memory_slot *memslot; + struct kvm_memory_slot *memslot, *slot; struct kvm_memory_slot old, new; struct kvm_memslots *slots, *old_memslots; @@ -737,13 +736,11 @@ int __kvm_set_memory_region(struct kvm *kvm, /* Check for overlaps */ r = -EEXIST; - for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { - struct kvm_memory_slot *s = &kvm->memslots->memslots[i]; - - if (s == memslot || !s->npages) + kvm_for_each_memslot(slot, kvm->memslots) { + if (slot->id >= KVM_MEMORY_SLOTS || slot == memslot) continue; - if (!((base_gfn + npages <= s->base_gfn) || - (base_gfn >= s->base_gfn + s->npages))) + if (!((base_gfn + npages <= slot->base_gfn) || + (base_gfn >= slot->base_gfn + slot->npages))) goto out_free; }