Re: [PATCH 0/5] Add support for ppc64le in kvmtool

[Laurent Vivier <lvivier@redhat.com>]

On 04/04/2016 10:34, Balbir Singh wrote:
> On Fri, Apr 1, 2016 at 11:12 AM, Balbir Singh <bsingharora@gmail.com> wrote:
>>
>>
>> On 01/04/16 00:38, Laurent Vivier wrote:
>>> Hi,
>>>
>>>
>>> could you add "kvmtool" in the subject, next time, please? :)
>>> And it could be a good idea to send to kvm-ppc ML too.
>> You mean like in [kvmtool]? The cover letter does have kvmtool, I think
>> adding [kvmtool] tag helps. I'll keep it in mind
>>> On 31/03/2016 13:28, Balbir Singh wrote:
>>>> Changelog v2: Add support for running a task on all cpus by
>>>>               Michael Ellerman. Large improvements to patch 2/4
>>>>
>>>> This patchset adds support for ppc64le. As a part of the support 1/4 converts
>>>> key data structures in the fdt to big endian. 2/4 introduces h_set_mode call
>>>> to support little endian interrupt processing. This requires support to execute
>>>> and queue commands to a particular vcpu and hence a generic infrastructure
>>>> is added in patch 2/4. Patch 3/4 fixes a race condition found during exit.
>>>> Patch 4/4 adds support for fixing spapr_pci to support little endian guests
>>>> so that virtio-pci can be detected and virtio can work
>>>>
>>>> This patchset was tested on x64 (on my laptop) and on a ppc64le system.
>>>>
>>>> Balbir Singh (5):
>>>>   Add basic little endian support.
>>>>   Add basic infrastructure to run tasks on vCPUs
>>>>   Implement H_SET_MODE for ppc64le
>>>>   Fix a race during exit processing
>>>>   Implement spapr pci for little endian systems.
>>> I was trying to use kvmtool on ppc64, some days ago, and I was not able
>>> to run anything (yes, I'm stupid), So could you also update the README
>>> with some ppc64/ppc64le stuff explaining how to use kvmtool on POWER?
>> No.. I don't think anyone is stupid, may be it just doesn't work. For ppc64le
>> here are the steps. I'll write a README after this series is committed
>>
>> 1. Make sure you have this patchset
>> 2. Compile a ppc64le_defconfig kernel
>> 3. Strip the elf header from vmlinux (yes, we don't yet have an elf parser - TODO)
>> 4. lkvm run -c <cpus> -m <mem{constrained to 4G}> -k <kernel from step 3> -i <initrd> -d <diskimage> -p <args> --console hv
>>
>> There are two limitations that need to be fixed
>> 1. memory is limited to 4G because of the way RTAS is currently setup in kvmtool, I have a brute force
>>    fix for it, I'll post it after this series is merged
>> 2. HPT size is limited to 16MB, will post a patch after this series is merged

Do you know David Gibson is working on a patch series for QEMU/KVM to
change the size of the HPT while the guest is running?

http://patchwork.ozlabs.org/patch/599965/

>>
>> TODOs
>> 1. Implement an elf parser so that we don't have to do step 3
>>
>>
>>> Or give me a link to the information, and I'll do.
>> I hope this helps, I can do some documentation once we get the limitations and TODOs
>> resolved
>>> Thanks,
>>> Laurent
>> Thanks for looking into this
>> Balbir
> 
> Hi,

Hi,

> Did the instructions help? Any luck with running kvmtool?
> 

This is helpful but I didn't have the time to try again.

Just one more question: how do you strip the ELF header (step 3)?

Thanks,
Laurent