From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: qemu-kvm-1.1.0 crashing with kernel 3.5.0-rc6 Date: Tue, 31 Jul 2012 19:46:38 +0300 Message-ID: <50180BEE.6000409@redhat.com> References: <5015662A.2000006@redhat.com> <501577D1.7030205@googlemail.com> <20120729175453.GA32360@redhat.com> <50158A97.3050909@googlemail.com> <50169389.1020607@googlemail.com> <50169421.6060406@redhat.com> <50169515.7050900@googlemail.com> <5016B8C3.7040103@redhat.com> <20120730233616.GA24530@amt.cnet> <5017A131.8000609@redhat.com> <20120731162940.GA7243@amt.cnet> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Chris Clayton , Gleb Natapov , Eric Northup , kvm@vger.kernel.org, Jan Kiszka To: Marcelo Tosatti Return-path: Received: from mx1.redhat.com ([209.132.183.28]:55020 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751793Ab2GaQqr (ORCPT ); Tue, 31 Jul 2012 12:46:47 -0400 In-Reply-To: <20120731162940.GA7243@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: On 07/31/2012 07:29 PM, Marcelo Tosatti wrote: >> >> So the same problem should happen with %fs and %gs, no? > > AFAICS: > > depends on CONFIG_X86_32_LAZY_GS for GS, unconditional for FS. This fs/gs were already in there, I wonder how it wasn't broken before. Something's fishy here. > >> x86_64 is safe, since it entry_64.S never saves/restores segment registers. > > Is the comment > > /* > * The sysexit path does not restore ds/es, so we must set them > * to > * a reasonable value ourselves. > */ > > Correct? > > syscall_exit -> syscall_exit_work -> resume_userspace -> > restore_all -> RESTORE_REGS > That's the non-sysexit path (could have arrived here by sysenter). Look at sysenter_exit. -- error compiling committee.c: too many arguments to function