Re: "X86_PV_VCPU_MSRS record truncated" during domain restore

[Massimo Colombi <mcolombi1@gmail.com>]

The patches (that are attached to "[PATCH RFC 0/4] Fix issues with 
zero-length records in migration v2") work!

I patched locally qubes-builder to import your patches and recreate rpm 
files. These patches also work on Xen 4.6.1.

Best regards,

   Massimo

On 07/21/2016 10:53 AM, Andrew Cooper wrote:
> On 21/07/2016 09:39, Massimo Colombi wrote:
>> This is the output of verify-stream-v2:
>>
>> [user@dom0 scripts]$ sudo xl save fedora-23-dvm /fedora-23-dvm-savefile
>> Saving to /fedora-23-dvm-savefile new xl format (info 0x3/0x0/1991)
>> xc: info: Saving domain 4, type x86 PV
>> xc: Frames: 912384/912384  100%
>> xc: End of stream: 0/0    0%
>>
>> [user@dom0 scripts]$ ./verify-stream-v2 -f xl -i /fedora-23-dvm-savefile
>> Stream Error:
>> Traceback (most recent call last):
>>    File "./verify-stream-v2", line 82, in read_stream
>>      VerifyLibxl(info, stream_read).verify()
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxl.py",
>> line 82, in verify
>>      while self.verify_record() != REC_TYPE_end:
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxl.py",
>> line 136, in verify_record
>>      record_verifiers[rtype](self, content[:length])
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxl.py",
>> line 155, in verify_record_libxc_context
>>      VerifyLibxc(self.info, self.read).verify()
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxc.py",
>> line 132, in verify
>>      while self.verify_record() != REC_TYPE_end:
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxc.py",
>> line 227, in verify_record
>>      record_verifiers[rtype](self, content[:length])
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxc.py",
>> line 429, in <lambda>
>>      VerifyLibxc.verify_record_x86_pv_vcpu_generic(s, x, "msrs"),
>>    File "/usr/lib64/python2.7/site-packages/xen/migration/libxc.py",
>> line 323, in verify_record_x86_pv_vcpu_generic
>>      " bytes long" % (name, minsz))
>> RecordError: X86_PV_VCPU_msrs record length must be at least 8 bytes long
>>
>>
>> On 07/21/2016 02:10 AM, Andrew Cooper wrote:
>>> Is it possible to do an `xl save` equivalent on the domain, and run
>>> tools/python/scripts/verify-stream-v2 against the resulting file?  That
>>> should identify whether it is a malformed X86_PV_VCPU_MSRS record but
>>> otherwise intact stream, or whether the stream becomes corrupted
>>> elsewhere?
>> Thanks for your explanation of the bug.
> I should also improve the reported error message.
>
> Do you mind rerunning with an extra -v to dump a list of the records
> found in the stream?
>
> ~Andrew


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel