From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932253AbZB1Bwm (ORCPT ); Fri, 27 Feb 2009 20:52:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755929AbZB1BnG (ORCPT ); Fri, 27 Feb 2009 20:43:06 -0500 Received: from mx2.redhat.com ([66.187.237.31]:41775 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754448AbZB1Bl6 (ORCPT ); Fri, 27 Feb 2009 20:41:58 -0500 From: Avi Kivity To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 15/30] KVM: MMU: handle compound pages in kvm_is_mmio_pfn Date: Sat, 28 Feb 2009 03:41:34 +0200 Message-Id: <1235785309-12835-16-git-send-email-avi@redhat.com> In-Reply-To: <1235785309-12835-1-git-send-email-avi@redhat.com> References: <1235785309-12835-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel 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 Acked-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- 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; } -- 1.6.0.6