Qemu PPC64 kvm no display if  --device virtio-gpu-pci is selected

Hi,
i did many tests on qemu 2.8 on my BE machines and i found an issue that i think was need to be reported

Test Machines BE 970MP 

if i setup qemu with

qemu-system-ppc64 -M 1024 --display sdl(or gtk),gl=on --device virtio-gpu-pci,virgl --enable-kvm and so and so

result is doubled window one is vga other is virtio-gpu-pci without any start of the VM . pratically i dont have any output of openbios and on the virtual serial output

the same issue i found is if i select:
qemu-system-ppc64 -M 1024 --display gtk(or sdl) --device virtio-gpu-pci --enable-kvm and so and so


i had been try to change all the -M types of all kind of pseries without any positive result.

Ciao 
Luigi

Hi! I think unless you use "-vga none" or "-nodefaults", QEMU will always start your guest with a VGA card by default, so if you add an additional "--device virtio-gpu-pci", you'll end up with a guest that has two video cards, one VGA and one virtio-gpu.
Also there is a known bug in the SLOF version that has been shipped with QEMU 2.8, which causes trouble with virtio-gpu:
http://git.qemu-project.org/?p=SLOF.git;a=commitdiff;h=38bf852e73ce6f0ac801dfe8ef1545c4cd0b5ddb
Please try again with the latest release candidate of QEMU 2.9, it should be fixed there.
(But please note that SLOF does not contain a driver for virtio-gpu, so you won't see any output from the firmware when starting your guest ... i.e. you'll just see some output once Linux has been started)

Hi Thomas, thanks for your reply i will test and report my experience ASAP 

Ciao
Luigi 

Hi Thomas with 2.9 rc1 i have this with --enable-kvm

emu-system-ppc64 --enable-kvm
qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS

and the qemu dont run.

Ciao 
Luigi 

Hi Thomas,

just exit like it is an error with a wrong option.
the output is only this   qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS
Same is if i add all the options i have the seme error.
look like qemu need for run in kvm  a  kernel with XICS option enabled and XICS  is present only from ibm power 5 to up if i remember good.
After work i can test it if needed on Qoriq e5500 too for check if there is the same issue on an emb ppc64 processor.

Ciao
Luigi



On 22.03.2017 14:35, luigiburdo wrote:
> Hi Thomas with 2.9 rc1 i have this with --enable-kvm
>
> emu-system-ppc64 --enable-kvm
> qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS
>
> and the qemu dont run.

Does it exit, or just hang afterwards? Was this with or without --device
virtio-gpu-pci option? Do you get any output if you run QEMU with
"-nographic" instead?

 Thomas




Hi Cédric,

i have the 4.11 rc1 . on fedora 25 ppc 64 on both machine Qoriq and on G5 Quad.

On the 2.8 this issue isnt present but
I did the test o Qoriq  e5500 a book3e processor and on 2.8 if i made:

qemu-system-ppc64 --enable-kvm the true result is:
qemu-system-ppc64: Unable to find CPU definition: host

on qemu 2.9 rc1

./qemu-system-ppc64 --enable-kvm i have :
qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS

On Qoriq if i pass the -cpu e500 (normal thing) all is working right qemu 2.9rc1 all boot and so and so.

On G5 the -cpu variable dont fix the issue.

I can build a new kernel release , usually mine dont have xics enabled because G5 dont have that feature, if needed i can enable it for testing.


Hope my english is understandable.

ciao

Luigi

________________________________
Da: Qemu-ppc <email address hidden> per conto di Cédric Le Goater <email address hidden>
Inviato: mercoledì 22 marzo 2017 18.29
A: Thomas Huth; Bug 1674925; <email address hidden>
Cc: <email address hidden>
Oggetto: Re: [Qemu-ppc] [Qemu-devel] [Bug 1674925] Re: Qemu PPC64 kvm no display if --device virtio-gpu-pci is selected

On 03/22/2017 03:15 PM, Thomas Huth wrote:
> On 22.03.2017 14:35, luigiburdo wrote:
>> Hi Thomas with 2.9 rc1 i have this with --enable-kvm
>>
>> emu-system-ppc64 --enable-kvm
>> qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS
>>
>> and the qemu dont run.
>
> Does it exit, or just hang afterwards? Was this with or without --device
> virtio-gpu-pci option? Do you get any output if you run QEMU with
> "-nographic" instead?

I guess this is an issue with the host kernel. Which one are you running ?

C.






Hello Cédric,

with your last message you made me think about and make more test.

>The default machine for qemu-system-ppc64 is pseries.
yes usually with 2.8 i  boot  the VM without issue on G5 Quad  with the option  -M  pseries from 2.1 to 2.5 with kvm-pr enabled.
i did the tests and with all pseries now on 2.9 i have the same issue.
example:
qemu-system-ppc64 --enable-kvm -cpu 970fx_v2.0 -m 1024 -M pseries-2.1
qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS

but no issue if i run with -M mac99 before 2.9 was not possible use it on qemu-system-ppc64
It means it will no possible anymore in future release of qemu use open firmware on powermacs any moore?


>I admit the message is not very clear, but the host kernel is
>using a dev config.

Im so sorry, i learn English by my self reading ml and on irc chatting is too difficult where no one speak English  around.

>> On Qoriq if i pass the -cpu e500 (normal thing) all is working right qemu 2.9rc1
>> all boot and so and so.
>but you must be changing the machine right ?
not on Qoriq because it is book3e and is not so flexible like the G5 Quad who is book3s machine.
i can run qemu kvm only with emb hardware on Qoriq

>>On G5 the -cpu variable dont fix the issue.
>with which machine ?
On PowerMac G5 Quad 970MP it have similar hardware configuration of IBM intellistation power 285

> >I can build a new kernel release , usually mine dont have xics enabled because G5
>> dont have that feature, if needed i can enable it for testing.**
>Yes that would be interesting.

I will do ASAP just the time to build it .

Thank you really much for your time and patience.
Luigi
________________________________


Hi Cèdric,

first of all thanks for your relpy.



>I have some difficulty sorting out what is going on and what
>could be considered a regression :/ you are reporting many
>issues at the same time with a home made kernel.

>Could you please use the kernel shipped with the distro to
>start with ?

I can do it and report.

> yes usually with 2.8 i  boot  the VM without issue on G5 Quad  with the option
> -M  pseries from 2.1 to 2.5 with kvm-pr enabled.
> i did the tests and with all pseries now on 2.9 i have the same issue.
> example:
> qemu-system-ppc64 --enable-kvm -cpu 970fx_v2.0 -m 1024 -M pseries-2.1
> qemu-system-ppc64: KVM and IRQ_XICS capability must be present for in-kernel XICS

>This error message is because your host kernel lacks in-kernel XICS,
>but you are saying that was not an issue with QEMU-2.8. Correct ?

Exactly i have the same on Qoriq too.

>Here is the command line I used on a 17.04 host :
>qemu-system-ppc64 -M pseries-2.[1-8],accel=kvm,kvm-type=PR -cpu 970fx_v2.0 -m 1024 -nographic

I will try your same command line and see what will exit on me.
I cant use qemu on 17.04 host because there is no more support for PPC32, PPC64 dead line is 16.10 and last working version
of qemu on PPC  is 2.6.1  i dint try 2.9 there if needed i can do i have ubuntu mate 17.04 installed too.

>Did we introduce a regression in compatibility in QEMU 2.9 ?  or
Im facing many issue on this last update im try to help how i can before all come upstream.
i like really much qemu. i can help in testing on PPC64 Be if need with my hw.
>was it bogus before ? That needs a little digging. I did not work
>on that part.
dont worry you did much

Thanks
Luigi





Hi Cèdric,

i had been build the kernel with the Xics option enabled and all work on G5 970MP on Mate 17.04

i will test the same kernel of Fedora server PPC64 and see if there will work too.

but it is strange thing, because the option was not needed (by the kernel default)

on PowerMacs and was not need to be enabled on Qemu 2.8.

I suggest to add this in the user faq PowerPC.


I  will test it on Qoriq too if kernel build with this option enabled and if all work ok there too

in case i will report as usual.


I will warn all the PowerPc comunity about if the qemu devs will need to have Xics turned on as default in the kernel

Thanks for your support
Luigi

________________________________


Hi,

now i understand .  xics  have to be build in kernel and is needed by qemu 2.9 with kvm.
if is not present in the kernel have the issue that i  been reported about xics.
I make a test on ubuntu 16.10 and on 17.04. the two distro are ppc 32 and generic.
i had build the stable kernel 4.10.5 two times with the same config  the  only parameter that  i had change  was the xics one was yes and the other was no.

On the two ubuntu version when  i run kernel without xics i had  the issue reported. if i run the kernel with xics enabled qemu 2.9 is working and was gave no issue.
but ...
on Fedora server 25 ppc64 if xics is present in the kernel the system (fedora) not run and freeze after the kernel bootstrap.



Hope all is understandable

Thanks
Luigi



When you use "-vga none" or "-nodefaults" with that kernel where you've enabled xics, do you now get some output in the windows once Linux has booted?

hi thomas on Qoriq Xics isnt present and cant be selected and i dont have video output too
this is a shot of the kernel config.
On G5 Quad i will made a shoot too i thinks screenshots is better then may english knowledge :P


attched the booted mate 16.10 Qemu system ppc64 --kvm on Qoriq without video initialized
only way i have to see something is with --serial stdio 

here i post the log of Qemu-system-ppc64 i filed a new bug about https://bugs.launchpad.net/qemu/+bug/1677247

soon the G5 Quad shots

Hi thomas,
this is the quad G5 shot on ubuntu mate 17.04 with last stable kernel 4.10.7 with xics builded inside
you can see i have the same result i have on Qoriq on fedora ppc64 . the only way for see something is use -serial stdio option

sorry for the extra comment on g5 quad i use this options 
gigi@gigi-desktop:~/qemu-2.9.0-rc1/ppc64-softmmu$ sudo ./qemu-system-ppc64 -enable-kvm -m 1024 -display sdl,gl=on -device virtio-gpu-pci,virgl  --nodefaults -vga none  -M pseries-2.5 -smp 2 -serial stdio

for no serial 

sudo ./qemu-system-ppc64 -enable-kvm -m 1024 -display sdl,gl=on -device virtio-gpu-pci,virgl  --nodefaults -vga none  -M pseries-2.5 -smp 2 -serial stdio .
you can see i dont have any output on the virtio-gpu-pci . itry with virgl and without and i try with -device virtio-vga too .. all gave the same result changing the pseries too.


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