Re: pvgrub "Error 9: Unknown boot failure" booting Debian Jessie kernel (Was: Re: [PATCH v5 6/9] libxc: create unmapped initrd in domain builder if supported)

From: Juergen Gross <jgross@suse.com>
To: Ian Campbell <ian.campbell@citrix.com>, Wei Liu <wei.liu2@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	xen-devel@lists.xen.org, ian.jackson@eu.citrix.com,
	stefano.stabellini@eu.citrix.com, roger.pau@citrix.com
Subject: Re: pvgrub "Error 9: Unknown boot failure" booting Debian Jessie kernel (Was: Re: [PATCH v5 6/9] libxc: create unmapped initrd in domain builder if supported)
Date: Mon, 30 Nov 2015 17:15:45 +0100	[thread overview]
Message-ID: <565C7631.4000505@suse.com> (raw)
In-Reply-To: <1448890911.15768.39.camel@citrix.com>

On 30/11/15 14:41, Ian Campbell wrote:
> On Mon, 2015-11-30 at 13:16 +0000, Ian Campbell wrote:
>> On Mon, 2015-11-30 at 13:59 +0100, Juergen Gross wrote:
>>> On 30/11/15 13:35, Ian Campbell wrote:
>>>> FYI attempting to upgrade osstest to use Debian Jessie in the guest
>>>> seems
>>>> to have exposed another issue here.
>>>>
>>>> http://logs.test-lab.xenproject.org/osstest/logs/65172/test-amd64-amd
>>>> 64-amd64-pvgrub/info.html
>>>>
>>>>       Booting 'Debian GNU/Linux, kernel 3.16.0-4-amd64'
>>>>
>>>>     root  (hd0,0)
>>>>      Filesystem type is ext2fs, partition type 0x83
>>>>     kernel  /boot/vmlinuz-3.16.0-4-amd64 root=UUID=12447529-e85a-
>>>> 4b41-86b6-3e83ccfc
>>>>     1377 ro 
>>>>     initrd  /boot/initrd.img-3.16.0-4-amd64
>>>>
>>>>     ============= Init TPM Front ================
>>>>     Tpmfront:Error Unable to read device/vtpm/0/backend-id during
>>>> tpmfront initialization! error = ENOENT
>>>>     Tpmfront:Info Shutting down tpmfront
>>>>     pin_table(x) returned 1357193
>>>>     close(3)
>>>>
>>>>     Error 9: Unknown boot failure
>>>>
>>>>     Press any key to continue...
>>>>
>>>> xen.git 6853c9bf9ff0 is OK, whereas 713b7e4ef2aa is not. Adding your
>>>> two
>>>> outstanding patches:
>>>>     libxc: correct domain builder for 64 bit guest with 32 bit tools
>>>>     libxc: use correct return type for do_memory_op()
>>>>
>>>> Doesn't appear to have helped. Anyway, I was in the process of
>>>> investigating/bisecting etc but since I was mailing you any way I
>>>> thought
>>>> I'd mention it. I'll start a fresh thread once I have some more to go
>>>> on.
>>>
>>> When something was wrong with pvgrub in my tests of the patches it died
>>> right away and didn't show random errors later. I don't think the
>>> problem you are seeing is related to my recent changes. OTOH I have
>>> been
>>> wrong before. :-(
>>
>> Bisection has blamed 06954411ee14 "xen: add generic flag to elf_dom_parms
>> indicating support of unmapped initrd" which I'm struggling to explain
>> right now...
> 
> And trying again it has blamed ea7c8a3d0e82 "libxc: reorganize domain
> builder guest memory allocator" which is far more likely.
> 
> I double checked clean rebuilds twice this time and ea7c8a3d0e82 is bad
> while 6853c9bf9ff0 "MINIOS_UPSTREAM_REVISION Update" is good.
> 
> Now, the question is why...

Indeed.

I can't spot anything wrong with that patch. I could imagine the change
is triggering an issue which has been present in pvgrub before but
didn't show up.

I'll try to trigger it on my machine and see if I can get some more
debug information.

Juergen