Re: [Qemu-devel] qemu-system-sparc64 hang (possibly virtio related?) with 2.1

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> writes:

> Stefan Hajnoczi <stefanha@gmail.com> writes:
>
>> On Tue, Sep 02, 2014 at 02:12:45PM +0100, Mark Cave-Ayland wrote:
>>> Fortunately I can reproduce the issue with a debug-enabled build of
>>> qemu-system-sparc64, and I've posted a backtrace obtained during the hung
>>> state at http://www.ilande.co.uk/tmp/sparc64-gdb-bt.txt. I can't see
>>> anything too obvious, other than that the ppoll() could possibly be waiting
>>> for a bad file descriptor?
>>
>> The backtrace looks like a normal QEMU run.  Nothing obvious there.
>>
>> This suggests the QEMU monitor is still operational and the guest is
>> still executing code.
>>
>> Does the I/O time out inside the guest?  Normally messages are printed
>> in dmesg if I/O requests are pending for too long.
>
> I am also finding this on ppc64. The system hang even with virtio-9p, so
> it may not be virtio blk related. git bisect is complicated because few
> commits in between cause other boot failures with ppc64.

The bad commit is:

git show cc943c36faa192cd4b32af8fe5edb31894017d35
commit cc943c36faa192cd4b32af8fe5edb31894017d35
Author: Jan Kiszka <jan.kiszka@siemens.com>
Date:   Sun Jul 27 09:08:29 2014 +0200

    pci: Use bus master address space for delivering MSI/MSI-X messages


git bisect log
git bisect start
# good: [5149e557d786ab83748588c9b1b13b43c81af6ab] Open 2.1 development tree
git bisect good 5149e557d786ab83748588c9b1b13b43c81af6ab
# bad: [246ad8e69be03d2774401adf63d7e1da8df166ac] hw/9pfs: Don't return type from host in readdir on local 9p filesystem
git bisect bad 246ad8e69be03d2774401adf63d7e1da8df166ac
# good: [d1a721ab816d1b954c0988aafdec4e109b953a9f] target-ppc: Add POWER8's TIR SPR
git bisect good d1a721ab816d1b954c0988aafdec4e109b953a9f
# good: [85d1277e668106294d134a101729c6f36289da1a] virtio: move common virtio properties to bus class device
git bisect good 85d1277e668106294d134a101729c6f36289da1a
# good: [86298845e127365e8a5b7419a5ee9039bbd1837f] qtest: Adding qtest_memset and qmemset.
git bisect good 86298845e127365e8a5b7419a5ee9039bbd1837f
# bad: [33886ebeec0c0ff6253a49253fae0db44c9ed0f3] Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging
git bisect bad 33886ebeec0c0ff6253a49253fae0db44c9ed0f3
# bad: [8e6e2c2ae7a81f625cf1cb320891d5270e277548] Merge remote-tracking branch 'remotes/qmp-unstable/queue/qmp' into staging
git bisect bad 8e6e2c2ae7a81f625cf1cb320891d5270e277548
# good: [39ba3bf69c4ef4d8a8b683ee7282efd25b3f01ff] qcow2: fix new_blocks double-free in alloc_refcount_block()
git bisect good 39ba3bf69c4ef4d8a8b683ee7282efd25b3f01ff
# good: [5edbdbcdf882e4220adc7dbf433351077cd1fbbc] ivshmem: check the value returned by fstat()
git bisect good 5edbdbcdf882e4220adc7dbf433351077cd1fbbc
# bad: [f2c85a2f36f57f155cda7bc9f7c42b44f1a2439e] Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging
git bisect bad f2c85a2f36f57f155cda7bc9f7c42b44f1a2439e
# bad: [988eba0f681bd4f82e9e02998da8106f165ed82c] pc-dimm: fix up error message
git bisect bad 988eba0f681bd4f82e9e02998da8106f165ed82c
# bad: [d209c7440a642ba08bbb0f13e22390460d3661ed] hw/audio/intel-hda: Fix MSI capability address
git bisect bad d209c7440a642ba08bbb0f13e22390460d3661ed
# bad: [cc943c36faa192cd4b32af8fe5edb31894017d35] pci: Use bus master address space for delivering MSI/MSI-X messages
git bisect bad cc943c36faa192cd4b32af8fe5edb31894017d35
# good: [2d591ce2aeebf9620ff527c7946844a3122afeec] Merge remote-tracking branch 'remotes/mdroth/qga-pull-2014-08-08' into staging
git bisect good 2d591ce2aeebf9620ff527c7946844a3122afeec
# first bad commit: [cc943c36faa192cd4b32af8fe5edb31894017d35] pci: Use bus master address space for delivering MSI/MSI-X messages
-bash-4.2#