From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: qemu-kvm-1.0.1 - unable to exit if vcpu is in infinite loop Date: Mon, 02 Jul 2012 09:05:57 +0200 Message-ID: <4FF14855.2040306@siemens.com> References: <4FEC56B2.6050502@dlhnet.de> <4FEC5B5A.4060302@siemens.com> <4FEC7214.2020900@dlhnet.de> <4FEC76A8.6060100@siemens.com> <4FEC866F.5000402@dlhnet.de> <4FEC8722.7070301@redhat.com> <7C6F41F3-D0BC-4753-853D-E68B2AAAAADB@dlhnet.de> <4FF00825.7090606@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , "kvm@vger.kernel.org" , "qemu-devel@nongnu.org" To: Peter Lieven Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On 2012-07-01 21:18, Peter Lieven wrote: > > Am 01.07.2012 um 10:19 schrieb Avi Kivity: > >> On 06/28/2012 10:27 PM, Peter Lieven wrote: >>> >>> Am 28.06.2012 um 18:32 schrieb Avi Kivity: >>> >>>> On 06/28/2012 07:29 PM, Peter Lieven wrote: >>>>>> Yes. A signal is sent, and KVM returns from the guest to userspace on >>>>>> pending signals. >>>> >>>>> is there a description available how this process exactly works? >>>> >>>> The kernel part is in vcpu_enter_guest(), see the check for >>>> signal_pending(). But this hasn't seen changes for quite a long while. >>> >>> Thank you, i will have a look. I noticed a few patches that where submitted >>> during the last year, maybe one of them is related: >>> >>> Switch SIG_IPI to SIGUSR1 >>> Fix signal handling of SIG_IPI when io-thread is enabled >>> >>> In the first commit there is mentioned a "32-on-64-bit Linux kernel bug" >>> is there any reference to that? >> >> >> http://web.archiveorange.com/archive/v/1XS1vwGSFLyYygwTXg1K. Are you >> running 32-on-64? > > I think the issue occurs when running a 32-bit guest on a 64-bit system. Afaik, the > isolinux loader where is see the race is 32-bit altough it is a 64-bit ubuntu lts > cd image. The second case where i have seen the race is on shutdown of a > Windows 2000 Server which is also 32-bit. "32-on-64" particularly means using a 32-bit QEMU[-kvm] binary on a 64-bit host kernel. What does "file qemu-system-x86_64" report about yours? Jan -- Siemens AG, Corporate Technology, CT RTC ITP SDP-DE Corporate Competence Center Embedded Linux