From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755127AbYI1Pvj (ORCPT ); Sun, 28 Sep 2008 11:51:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753401AbYI1Ppz (ORCPT ); Sun, 28 Sep 2008 11:45:55 -0400 Received: from mx2.redhat.com ([66.187.237.31]:50887 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753366AbYI1Ppw (ORCPT ); Sun, 28 Sep 2008 11:45:52 -0400 From: Avi Kivity To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, Marcelo Tosatti Subject: [PATCH 22/25] KVM: opencode gfn_to_page in kvm_vm_fault Date: Sun, 28 Sep 2008 18:44:58 +0300 Message-Id: <1222616701-1206-23-git-send-email-avi@redhat.com> In-Reply-To: <1222616701-1206-1-git-send-email-avi@redhat.com> References: <1222616701-1206-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marcelo Tosatti kvm_vm_fault is invoked with mmap_sem held in read mode. Since gfn_to_page will be converted to get_user_pages_fast, which requires this lock NOT to be held, switch to opencoded get_user_pages. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- virt/kvm/kvm_main.c | 19 ++++++++++++------- 1 files changed, 12 insertions(+), 7 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f42d5c2..2907d05 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1394,17 +1394,22 @@ out: static int kvm_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { + struct page *page[1]; + unsigned long addr; + int npages; + gfn_t gfn = vmf->pgoff; struct kvm *kvm = vma->vm_file->private_data; - struct page *page; - if (!kvm_is_visible_gfn(kvm, vmf->pgoff)) + addr = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(addr)) return VM_FAULT_SIGBUS; - page = gfn_to_page(kvm, vmf->pgoff); - if (is_error_page(page)) { - kvm_release_page_clean(page); + + npages = get_user_pages(current, current->mm, addr, 1, 1, 0, page, + NULL); + if (unlikely(npages != 1)) return VM_FAULT_SIGBUS; - } - vmf->page = page; + + vmf->page = page[0]; return 0; } -- 1.6.0.1