Re: Biweekly KVM Test report, kernel 51bfd299... qemu a1fce560...

Stefan Hajnoczi
2012-06-07T12:13:52Z

On Wed, Jun 6, 2012 at 3:17 AM, Ren, Yongjie <yongjie.ren@intel.com> wrote:
>> -----Original Message-----
>> From: Kevin Wolf [mailto:kwolf@redhat.com]
>> Sent: Monday, June 04, 2012 9:51 PM
>> To: Ren, Yongjie
>> Cc: Marcelo Tosatti; Avi Kivity; kvm@vger.kernel.org; Liu, RongrongX
>> Subject: Re: Biweekly KVM Test report, kernel 51bfd299... qemu
>> a1fce560...
>>
>> Am 01.06.2012 10:31, schrieb Kevin Wolf:
>> > Am 01.06.2012 09:57, schrieb Ren, Yongjie:
>> >>> -----Original Message-----
>> >>> From: Marcelo Tosatti [mailto:mtosatti@redhat.com]
>> >>> Sent: Thursday, May 31, 2012 4:28 AM
>> >>> To: Ren, Yongjie
>> >>> Cc: Kevin Wolf; Avi Kivity; kvm@vger.kernel.org; Liu, RongrongX
>> >>> Subject: Re: Biweekly KVM Test report, kernel 51bfd299... qemu
>> >>> a1fce560...
>> >>>
>> >>> On Tue, May 22, 2012 at 07:40:29AM +0000, Ren, Yongjie wrote:
>> >>>>> -----Original Message-----
>> >>>>> From: Kevin Wolf [mailto:kwolf@redhat.com]
>> >>>>> Sent: Monday, May 21, 2012 11:30 PM
>> >>>>> To: Ren, Yongjie
>> >>>>> Cc: Avi Kivity; kvm@vger.kernel.org; Liu, RongrongX
>> >>>>> Subject: Re: Biweekly KVM Test report, kernel 51bfd299... qemu
>> >>>>> a1fce560...
>> >>>>>
>> >>>>> Am 21.05.2012 11:45, schrieb Ren, Yongjie:
>> >>>>>>> -----Original Message-----
>> >>>>>>> From: Kevin Wolf [mailto:kwolf@redhat.com]
>> >>>>>>> Sent: Monday, May 21, 2012 5:05 PM
>> >>>>>>> To: Avi Kivity
>> >>>>>>> Cc: Ren, Yongjie; kvm@vger.kernel.org
>> >>>>>>> Subject: Re: Biweekly KVM Test report, kernel 51bfd299... qemu
>> >>>>>>> a1fce560...
>> >>>>>>>
>> >>>>>>> Am 21.05.2012 10:27, schrieb Avi Kivity:
>> >>>>>>>> On 05/21/2012 06:34 AM, Ren, Yongjie wrote:
>> >>>>>>>>> Hi All,
>> >>>>>>>>>
>> >>>>>>>>> This is KVM upstream test result against kvm.git
>> >>>>>>> 51bfd2998113e1f8ce8dcf853407b76a04b5f2a0 based on kernel
>> >>>>> 3.4.0-rc7,
>> >>>>>>> and qemu-kvm.git
>> a1fce560c0e5f287ed65d2aaadb3e59578aaa983.
>> >>>>>>>>>
>> >>>>>>>>> We found 1 new bug and 1 bug got fixed in the past two weeks.
>> >>>>>>>>>
>> >>>>>>>>> New issue (1):
>> >>>>>>>>> 1. disk error when guest boot up via qcow2 image
>> >>>>>>>>>   https://bugs.launchpad.net/qemu/+bug/1002121
>> >>>>>>>>>   -- Should be a regression on qemu-kvm.
>> >>>>>>>>>
>> >>>>>>>>
>> >>>>>>>> Kevin, is this the known regression in qcow2 or something new?
>> >>>>>>>
>> >>>>>>> If the commit ID is right, it must be something new. The
>> regression
>> >>> that
>> >>>>>>> Marcelo found was fixed in 54e68143.
>> >>>>>>>
>> >>>>>> Yes, it's right. This should be a new regression.
>> >>>>>> I looked at the comment of 54e68143, and found it was not related
>> >>> the
>> >>>>> issue I reported.
>> >>>>>>
>> >>>>>>> The Launchpad bug refers to commit e54f008ef, which doesn't
>> >>> include
>> >>>>> this
>> >>>>>>> fix indeed. So was the test repeated with a more current
>> qemu-kvm
>> >>>>>>> version after filing the bug in Launchpad, or is the commit ID in
>> this
>> >>>>>>> mail wrong?
>> >>>>>>>
>> >>>>>> Latest commit 3fd9fedb in qemu-kvm master tree still has this
>> issue.
>> >>>>>> And, the commit ID provided in Launchpad is correct.
>> >>>>>
>> >>>>> Can you please check if the bug exists in upstream qemu.git as well?
>> >>>>>
>> >>>> This bug doesn't exist on upstream qemu.git with latest commit:
>> >>> fd4567d9.
>> >>>> So, it should only exists on qemu-kvm tree.
>> >>>
>> >>> Please bisect manually (not using git bisect), with the attached list of
>> >>> commits. These are the qemu -> qemu-kvm merge commits in the
>> range
>> >>> described as bad/good.
>> >>>
>> >> The 1st bad commit in your attached list is abc551bd
>> >> More detailed info:
>> >> 171d2f2249a360d7d623130d3aa991418c53716d       good
>> >> fd453a24166e36a3d376c9bc221e520e3ee425af        good
>> >> abc551bd456cf0407fa798395d83dc5aa35f6dbb         bad
>> >> 823ccf41509baa197dd6a3bef63837a6cf101ad8         bad
>> >
>> > Thanks, this points to the qcow2 v3 changes. Let's try to find the exact
>> > culprit. I have rebased the qcow2 patches on top of that good merge
>> > (fd453a24). Please apply the attached mbox on top of this merge:
>> >
>> > git checkout fd453a24
>> > git am qcow2v3.mbox
>> >
>> > You can then start a git bisect between your new HEAD and fd453a24.
>>
>> Another thing you could try is if reverting e82dabd and bef0fd59 fixes
>> the problem for you.
>>
> After reverting bef0fd59, it can work fine.

I'm unable to reproduce this with qemu-kvm.git/master
(18b012756fd041556764dfa2bb1f307b6923fb71) or the commit you
3fd9fedb9fae4517d93d76e93a2924559cacf2f6 reported as bad. The RHEL 6
guest boots without any issues. My host kernel is Linux 3.2 (Debian
3.2.0-2-amd64). The guest is Linux 2.6.32-71.el6.

Since the guest sees a disk read error, it may be useful to add
printfs to hw/ide/core.c:ide_sector_read_cb(). Let's find out why the
disk read is failing.

Stefan