From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761958AbYDUKkk (ORCPT ); Mon, 21 Apr 2008 06:40:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754907AbYDUKao (ORCPT ); Mon, 21 Apr 2008 06:30:44 -0400 Received: from bzq-179-150-194.static.bezeqint.net ([212.179.150.194]:37945 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756166AbYDUKaK (ORCPT ); Mon, 21 Apr 2008 06:30:10 -0400 From: Avi Kivity To: kvm-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, Marcelo Tosatti Subject: [PATCH 31/31] KVM: MMU: kvm_pv_mmu_op should not take mmap_sem Date: Mon, 21 Apr 2008 13:29:57 +0300 Message-Id: <1208773797-7829-32-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.5 In-Reply-To: <1208773797-7829-1-git-send-email-avi@qumranet.com> References: <1208773797-7829-1-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marcelo Tosatti kvm_pv_mmu_op should not take mmap_sem. All gfn_to_page() callers down in the MMU processing will take it if necessary, so as it is it can deadlock. Apparently a leftover from the days before slots_lock. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 3 --- 1 files changed, 0 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 078a7f1..2ad6f54 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2173,8 +2173,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, int r; struct kvm_pv_mmu_op_buffer buffer; - down_read(¤t->mm->mmap_sem); - buffer.ptr = buffer.buf; buffer.len = min_t(unsigned long, bytes, sizeof buffer.buf); buffer.processed = 0; @@ -2194,7 +2192,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, r = 1; out: *ret = buffer.processed; - up_read(¤t->mm->mmap_sem); return r; } -- 1.5.5