Re: [PATCH v2 for-4.15 3/7] CHANGELOG.md: Add dom0/domU zstd compression support

[Julien Grall <julien@xen.org>]

On 30/03/2021 11:56, Jan Beulich wrote:
> On 30.03.2021 12:14, Julien Grall wrote:
>>
>>
>> On 30/03/2021 11:08, George Dunlap wrote:
>>>
>>>
>>>> On Mar 29, 2021, at 7:54 PM, Julien Grall <julien.grall.oss@gmail.com> wrote:
>>>>
>>>> Hi George,
>>>>
>>>> On Mon, 29 Mar 2021 at 17:15, George Dunlap <george.dunlap@citrix.com> wrote:
>>>>> diff --git a/CHANGELOG.md b/CHANGELOG.md
>>>>> index 8c89212f14..538eae611c 100644
>>>>> --- a/CHANGELOG.md
>>>>> +++ b/CHANGELOG.md
>>>>> @@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
>>>>>    - ARM SMMUv3 (Tech Preview)
>>>>>    - Intel Processor Trace support (Tech Preview)
>>>>>    - Named PCI devices for xl/libxl
>>>>> + - Support for zstd-compressed dom0 and domU kernels
>>>>
>>>> Looking at the log, the feature looks x86 only (at least the dom0 part).
>>>
>>> Oh, interesting.  So what about the following?
>>>
>>> - Support for zstd-compressed dom0 (x86) and domU kernels
>>
>> Sounds fine to me. Note that I haven't tried zstd-compressed for domu
>> Kernel on Arm.
>>
>> Maybe the author (Jan) can confirm whether this was plumbed in common
>> libxc code?
> 
> Well, I've followed the model used for other compression methods. I have
> no idea what this means or does not mean for Arm; in fact so far I was
> under the impression that like in the hypervisor decompression support
> was an x86-only feature, but from what you say I conclude I have been
> wrong with this.

We support gzip for dom0. For guests, I am not entirely sure what the 
state as I tend to uncompressed kernel every time.

Cheers,

-- 
Julien Grall