From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Tosatti Subject: Re: [PATCH v3 1/3] KVM: fix rcu usage warning in kvm_arch_vcpu_ioctl_set_sregs() Date: Wed, 19 Jan 2011 16:13:47 -0200 Message-ID: <20110119181347.GA13142@amt.cnet> References: <4D2D5AA6.9080804@cn.fujitsu.com> <4D3673A7.4090402@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity , LKML , KVM To: Xiao Guangrong Return-path: Received: from mx1.redhat.com ([209.132.183.28]:15364 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751412Ab1ASSPZ (ORCPT ); Wed, 19 Jan 2011 13:15:25 -0500 Content-Disposition: inline In-Reply-To: <4D3673A7.4090402@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Jan 19, 2011 at 01:16:23PM +0800, Xiao Guangrong wrote: > On 01/12/2011 03:39 PM, Xiao Guangrong wrote: > > Fix: > > > > [ 1001.499596] =================================================== > > [ 1001.499599] [ INFO: suspicious rcu_dereference_check() usage. ] > > [ 1001.499601] --------------------------------------------------- > > [ 1001.499604] include/linux/kvm_host.h:301 invoked rcu_dereference_check() without protection! > > ...... > > [ 1001.499636] Pid: 6035, comm: qemu-system-x86 Not tainted 2.6.37-rc6+ #62 > > [ 1001.499638] Call Trace: > > [ 1001.499644] [] lockdep_rcu_dereference+0x9d/0xa5 > > [ 1001.499653] [] gfn_to_memslot+0x8d/0xc8 [kvm] > > [ 1001.499661] [] gfn_to_hva+0x16/0x3f [kvm] > > [ 1001.499669] [] kvm_read_guest_page+0x1e/0x5e [kvm] > > [ 1001.499681] [] kvm_read_guest_page_mmu+0x53/0x5e [kvm] > > [ 1001.499699] [] load_pdptrs+0x3f/0x9c [kvm] > > [ 1001.499705] [] ? vmx_set_cr0+0x507/0x517 [kvm_intel] > > [ 1001.499717] [] kvm_arch_vcpu_ioctl_set_sregs+0x1f3/0x3c0 [kvm] > > [ 1001.499727] [] kvm_vcpu_ioctl+0x6a5/0xbc5 [kvm] > > > > Signed-off-by: Xiao Guangrong > > Ping ...? Applied this fix. For the make_all_cpus_request optimization, can you show numbers with this new version? Because now there is LOCK# similarly to the spinlock.