From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753362AbZBRNY3 (ORCPT ); Wed, 18 Feb 2009 08:24:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752048AbZBRNYP (ORCPT ); Wed, 18 Feb 2009 08:24:15 -0500 Received: from va3ehsobe004.messaging.microsoft.com ([216.32.180.14]:2989 "EHLO VA3EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751492AbZBRNYO (ORCPT ); Wed, 18 Feb 2009 08:24:14 -0500 X-Greylist: delayed 901 seconds by postgrey-1.27 at vger.kernel.org; Wed, 18 Feb 2009 08:24:14 EST X-BigFish: VPS3(zzzzzzz32i43j62h) X-Spam-TCS-SCL: 1:0 X-FB-SS: 5, X-WSS-ID: 0KF9J72-03-C6N-01 From: Joerg Roedel To: Avi Kivity CC: Marcelo Tosatti , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Joerg Roedel Subject: [PATCH 1/3] kvm mmu: handle compound pages in kvm_is_mmio_pfn Date: Wed, 18 Feb 2009 14:08:58 +0100 Message-ID: <1234962540-7131-2-git-send-email-joerg.roedel@amd.com> X-Mailer: git-send-email 1.5.6.4 In-Reply-To: <1234962540-7131-1-git-send-email-joerg.roedel@amd.com> References: <1234962540-7131-1-git-send-email-joerg.roedel@amd.com> X-OriginalArrivalTime: 18 Feb 2009 13:09:00.0194 (UTC) FILETIME=[106F9820:01C991CA] MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The function kvm_is_mmio_pfn is called before put_page is called on a page by KVM. This is a problem when when this function is called on some struct page which is part of a compund page. It does not test the reserved flag of the compound page but of the struct page within the compount page. This is a problem when KVM works with hugepages allocated at boot time. These pages have the reserved bit set in all tail pages. Only the flag in the compount head is cleared. KVM would not put such a page which results in a memory leak. Signed-off-by: Joerg Roedel --- virt/kvm/kvm_main.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 266bdaf..0ed662d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -535,8 +535,10 @@ static inline int valid_vcpu(int n) inline int kvm_is_mmio_pfn(pfn_t pfn) { - if (pfn_valid(pfn)) - return PageReserved(pfn_to_page(pfn)); + if (pfn_valid(pfn)) { + struct page *page = compound_head(pfn_to_page(pfn)); + return PageReserved(page); + } return true; } -- 1.5.6.4