Re: [Qemu-devel] [Qemu-ppc] ppc64 TCG emulation broken

[Nikunj A Dadhania]

Alexander Graf <address@hidden> writes:
> On 09/29/2016 09:47 AM, David Gibson wrote:
>> On Thu, Sep 29, 2016 at 12:41:04PM +0530, Bharata B Rao wrote:
>> [   78.015142] Kernel panic - not syncing: Attempted to kill init!
>>> exitcode=0x00000084
>>> [   78.015142]
>>> [   78.016926] CPU: 0 PID: 1 Comm: systemd Not tainted 4.6.4-301.fc24.ppc64 
>>> #1
>>> [   78.017726] Call Trace:
>>> [   78.019154] [c00000007e6638d0] [c0000000009df0f0]
>>> .dump_stack+0xa8/0xe8 (unreliable)
>>> [   78.022485] [c00000007e663960] [c0000000009dd6bc] .panic+0x12c/0x2fc
>>> [   78.022631] [c00000007e663a00] [c0000000000cd6a8] .do_exit+0xca8/0xcb0
>>> [   78.022735] [c00000007e663ae0] [c0000000000cd77c] 
>>> .do_group_exit+0x5c/0xf0
>>> [   78.022815] [c00000007e663b70] [c0000000000dd4ec] .get_signal+0x3bc/0x770
>>> [   78.022918] [c00000007e663c70] [c00000000001761c] .do_signal+0x4c/0x2a0
>>> [   78.023021] [c00000007e663db0] [c000000000017a4c] 
>>> .do_notify_resume+0xac/0xc0
>>> [   78.023411] [c00000007e663e30] [c000000000009944]
>>> .ret_from_except_lite+0x70/0x74
>>> [   78.077889] ---[ end Kernel panic - not syncing: Attempted to kill
>>> init! exitcode=0x00000084
>> Huh.  Well, that's unfortunate.  I don't imagine the guest is trying
>> to use any of those new POWER9 instructions, so I guess we must have
>> broken decode of one of the existing vector instructions with which it
>> shares some part of the opcode.
>>
>> Any chance you could trace this and work out what instruction is
>> giving the first illegal instruction exception?
>
> ... and whenever someone has some spare time, I would strongly advise 
> for implementing RISU on PowerPC to catch these things before they happen ;)
>
>    https://wiki.linaro.org/PeterMaydell/Risu

Ziviani is spending time to get this working for PowerPC

Regards
Nikunj