From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933166AbWLaNTy (ORCPT ); Sun, 31 Dec 2006 08:19:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933167AbWLaNTy (ORCPT ); Sun, 31 Dec 2006 08:19:54 -0500 Received: from il.qumranet.com ([62.219.232.206]:50202 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933166AbWLaNTx (ORCPT ); Sun, 31 Dec 2006 08:19:53 -0500 Subject: [PATCH 1/3] KVM: Fix GFP_KERNEL alloc in atomic section bug From: Avi Kivity Date: Sun, 31 Dec 2006 13:19:51 -0000 To: kvm-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, akpm@osdl.org References: <4597B8AB.6040504@qumranet.com> In-Reply-To: <4597B8AB.6040504@qumranet.com> Message-Id: <20061231131951.EF0552500F7@il.qumranet.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Ingo Molnar KVM does kmalloc() in an atomic section while having preemption disabled via vcpu_load(). Fix this by moving the ->*_msr setup from the vcpu_setup method to the vcpu_create method. (This is also a small speedup for setting up a vcpu, which can in theory be more frequent than the vcpu_create method). Signed-off-by: Ingo Molnar Signed-off-by: Avi Kivity Index: linux-2.6/drivers/kvm/vmx.c =================================================================== --- linux-2.6.orig/drivers/kvm/vmx.c +++ linux-2.6/drivers/kvm/vmx.c @@ -1094,14 +1094,6 @@ static int vmx_vcpu_setup(struct kvm_vcp rdmsrl(MSR_IA32_SYSENTER_EIP, a); vmcs_writel(HOST_IA32_SYSENTER_EIP, a); /* 22.2.3 */ - ret = -ENOMEM; - vcpu->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!vcpu->guest_msrs) - goto out; - vcpu->host_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!vcpu->host_msrs) - goto out_free_guest_msrs; - for (i = 0; i < NR_VMX_MSR; ++i) { u32 index = vmx_msr_index[i]; u32 data_low, data_high; @@ -1155,8 +1147,6 @@ static int vmx_vcpu_setup(struct kvm_vcp return 0; -out_free_guest_msrs: - kfree(vcpu->guest_msrs); out: return ret; } @@ -1906,13 +1896,33 @@ static int vmx_create_vcpu(struct kvm_vc { struct vmcs *vmcs; + vcpu->guest_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!vcpu->guest_msrs) + return -ENOMEM; + + vcpu->host_msrs = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!vcpu->host_msrs) + goto out_free_guest_msrs; + vmcs = alloc_vmcs(); if (!vmcs) - return -ENOMEM; + goto out_free_msrs; + vmcs_clear(vmcs); vcpu->vmcs = vmcs; vcpu->launched = 0; + return 0; + +out_free_msrs: + kfree(vcpu->host_msrs); + vcpu->host_msrs = NULL; + +out_free_guest_msrs: + kfree(vcpu->guest_msrs); + vcpu->guest_msrs = NULL; + + return -ENOMEM; } static struct kvm_arch_ops vmx_arch_ops = {