From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH] Fixed KVM problems with old DOS programs. Compatibility can be forced by module parameter. Date: Thu, 5 Nov 2015 17:19:27 +0100 Message-ID: <563B818F.6080008@redhat.com> References: <563A5D7D.4080201@wiesinger.com> <563A7827.8030506@redhat.com> <563A79B8.3020900@wiesinger.com> <563A80F4.6090204@redhat.com> <563B7ECB.9030504@wiesinger.com> <563B809D.5040306@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit To: Gerhard Wiesinger , kvm@vger.kernel.org Return-path: Received: from mail-wm0-f47.google.com ([74.125.82.47]:34959 "EHLO mail-wm0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162010AbbKEQTe (ORCPT ); Thu, 5 Nov 2015 11:19:34 -0500 Received: by wmll128 with SMTP id l128so15919879wml.0 for ; Thu, 05 Nov 2015 08:19:33 -0800 (PST) In-Reply-To: <563B809D.5040306@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 05/11/2015 17:15, Paolo Bonzini wrote: > > > On 05/11/2015 17:07, Gerhard Wiesinger wrote: >>> >> >> ./trace-cmd record -b 20000 -e kvm >> ./trace-cmd report | grep -i task_switch >> qemu-system-x86-6024 [001] 792774.719297: kvm_exit: reason task_switch >> rip 0x4883 info 158 4000000000 > > 0x158 is the segment selector of the incoming TSS, and the task switch > was caused by a far jump. > >> But I can't interpret it. > > Neither can I; you have to send the whole trace. > >> But I know my patch works well. Since it is >> just a module parameter it is fully backward compatible by default and >> because of the one liner no side effects are possible. So a intergration >> would be good. > > It's also papering over a bug, and likely the bug still triggers on > Intel systems. So it's not acceptable. > > Can you provide reproduction instructions please? At the very least, does it reproduce without KVM? Paolo