From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49208) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c7ifS-00047I-Kh for qemu-devel@nongnu.org; Fri, 18 Nov 2016 07:53:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c7ifN-0000mk-PT for qemu-devel@nongnu.org; Fri, 18 Nov 2016 07:53:22 -0500 Received: from 7.mo53.mail-out.ovh.net ([46.105.61.78]:34052) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c7ifN-0000mE-Iv for qemu-devel@nongnu.org; Fri, 18 Nov 2016 07:53:17 -0500 Received: from player158.ha.ovh.net (b7.ovh.net [213.186.33.57]) by mo53.mail-out.ovh.net (Postfix) with ESMTP id 4227244993 for ; Fri, 18 Nov 2016 13:53:15 +0100 (CET) Date: Fri, 18 Nov 2016 13:53:03 +0100 From: Greg Kurz Message-ID: <20161118135303.0b4f9006@bahia> In-Reply-To: <1b4598af-5109-b54e-7958-f8e9f346c1df@redhat.com> References: <1479285571-28145-1-git-send-email-thuth@redhat.com> <20161116131321.35d58700@bahia> <20161116122450.GC2050@work-vm> <20161116133756.76854958@bahia> <2f74eb45-b36d-3d4d-5b47-f06259ade5c4@redhat.com> <20161116151755.47c05cb7@bahia> <1b4598af-5109-b54e-7958-f8e9f346c1df@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] tests/postcopy: Use KVM on ppc64 only if it is KVM-HV List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laurent Vivier Cc: Thomas Huth , "Dr. David Alan Gilbert" , David Gibson , qemu-ppc@nongnu.org, Stefan Hajnoczi , qemu-devel@nongnu.org, Andrea Arcangeli , Eric Blake Hi Laurent, On Thu, 17 Nov 2016 21:22:33 +0100 Laurent Vivier wrote: > On 16/11/2016 15:17, Greg Kurz wrote: > > On Wed, 16 Nov 2016 14:17:47 +0100 > > Thomas Huth wrote: > > > >> On 16.11.2016 13:37, Greg Kurz wrote: > >>> On Wed, 16 Nov 2016 12:24:50 +0000 > >>> "Dr. David Alan Gilbert" wrote: > >>> > >>>> * Greg Kurz (groug@kaod.org) wrote: > >>>>> On Wed, 16 Nov 2016 09:39:31 +0100 > >>>>> Thomas Huth wrote: > >>>>> > >>>>>> The ppc64 postcopy test does not work with KVM-PR, and it is also > >>>>>> causing annoying warning messages when run on a x86 host. So let's > >>>>>> use KVM here only if we know that we're running with KVM-HV (which > >>>>>> automatically also means that we're running on a ppc64 host), and > >>>>>> fall back to TCG otherwise. > >>>>>> > [..] > > The changes to the code look ok and I prefer to spend time chasing the > > KVM PR issue rather than arguing on a comment... > > For the problem itself, it seems to appear only after a > BOOK3S_INTERRUPT_SYSCALL interrupt for an KVM_EXIT_PAPR_HCALL > (H_PUT_TERM_CHAR). In this case, KVM has to exit to QEMU to manage the > output. The following interrupt is always an BOOK3S_INTERRUPT_PROGRAM > with an emulation failure. > Which specific problem are you referring to ? On my side, when running postcopy-test in a nested guest, I hit either one of the three following issues (in decreasing order of probability of occurence): 1) "Memory content inconsistency at ..." like Stefan 2) "Unexpected 32 on dest_serial serial" accompanied by the following in dmesg [131613.428616] Couldn't emulate instruction 0x00000000 (op 0 xop 0) [131613.503515] kvmppc_handle_exit_pr: emulation at d8 failed (00000000) 3) hang because the destination QEMU is looping on: ioctl(19, KVM_RUN, 0) = 2 (RESUME_HOST) Host runs OpenPower HostOS (kernel 4.9, QEMU 2.7) and guest runs fedora25. Cheers. -- Greg > Laurent