From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755997AbYIWN7b (ORCPT ); Tue, 23 Sep 2008 09:59:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754497AbYIWNs5 (ORCPT ); Tue, 23 Sep 2008 09:48:57 -0400 Received: from mx2.redhat.com ([66.187.237.31]:52488 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754492AbYIWNs4 (ORCPT ); Tue, 23 Sep 2008 09:48:56 -0400 From: Avi Kivity To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, Ben-Ami Yassour Subject: [PATCH 35/40] KVM: direct mmio pfn check Date: Tue, 23 Sep 2008 16:46:49 +0300 Message-Id: <1222177614-26669-36-git-send-email-avi@redhat.com> In-Reply-To: <1222177614-26669-1-git-send-email-avi@redhat.com> References: <1222177614-26669-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ben-Ami Yassour Userspace may specify memory slots that are backed by mmio pages rather than normal RAM. In some cases it is not enough to identify these mmio pages by pfn_valid(). This patch adds checking the PageReserved as well. Signed-off-by: Ben-Ami Yassour Signed-off-by: Muli Ben-Yehuda Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 22 +++++++++++++++------- 1 files changed, 15 insertions(+), 7 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 7dd9b0b..5eb96c7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -76,6 +76,14 @@ static inline int valid_vcpu(int n) return likely(n >= 0 && n < KVM_MAX_VCPUS); } +static inline int is_mmio_pfn(pfn_t pfn) +{ + if (pfn_valid(pfn)) + return PageReserved(pfn_to_page(pfn)); + + return true; +} + /* * Switches to specified vcpu, until a matching vcpu_put() */ @@ -740,7 +748,7 @@ pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) } pfn = ((addr - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; - BUG_ON(pfn_valid(pfn)); + BUG_ON(!is_mmio_pfn(pfn)); } else pfn = page_to_pfn(page[0]); @@ -754,10 +762,10 @@ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) pfn_t pfn; pfn = gfn_to_pfn(kvm, gfn); - if (pfn_valid(pfn)) + if (!is_mmio_pfn(pfn)) return pfn_to_page(pfn); - WARN_ON(!pfn_valid(pfn)); + WARN_ON(is_mmio_pfn(pfn)); get_page(bad_page); return bad_page; @@ -773,7 +781,7 @@ EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(pfn_t pfn) { - if (pfn_valid(pfn)) + if (!is_mmio_pfn(pfn)) put_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); @@ -799,7 +807,7 @@ EXPORT_SYMBOL_GPL(kvm_set_page_dirty); void kvm_set_pfn_dirty(pfn_t pfn) { - if (pfn_valid(pfn)) { + if (!is_mmio_pfn(pfn)) { struct page *page = pfn_to_page(pfn); if (!PageReserved(page)) SetPageDirty(page); @@ -809,14 +817,14 @@ EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); void kvm_set_pfn_accessed(pfn_t pfn) { - if (pfn_valid(pfn)) + if (!is_mmio_pfn(pfn)) mark_page_accessed(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); void kvm_get_pfn(pfn_t pfn) { - if (pfn_valid(pfn)) + if (!is_mmio_pfn(pfn)) get_page(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_get_pfn); -- 1.6.0.1