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

[Balbir Singh <bsingharora@gmail.com>]

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

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