chore: support ppc64le and riscv64

[Desiki-high]

Changes

Add BASE_MAGIC_ID in ppc64le and riscv64 arches to support using snapshot in ppc64le and riscv64.

Reason

Ref:#4162 kata-containers#5 dragonflyoss/nydus#1510

Our project depends on firecracker's snapshot crate, we need to work on different arches like ppc64le and riscv64. I think many other projects must also work on ppc64le and riscv64.

License Acceptance

By submitting this pull request, I confirm that my contribution is made under
the terms of the Apache 2.0 license. For more information on following
Developer Certificate of Origin and signing off your commits, please check
CONTRIBUTING.md.

PR Checklist

• If a specific issue led to this PR, this PR closes the issue.
• The description of changes is clear and encompassing.
• Any required documentation changes (code and docs) are included in this PR.
• API changes follow the Runbook for Firecracker API changes.
• User-facing changes are mentioned in CHANGELOG.md.
• All added/changed functionality is tested.
• New TODOs link to an issue.
• Commits meet contribution quality standards.

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• This functionality cannot be added in rust-vmm.

[roypat]

Hi @Desiki-high,
thank you for your contribution. Firecracker does not support ppc64le and riscv64, so I don't think having these two constants here is a very good idea, as it might send a wrong message about which platforms Firecracker supports. From my understanding of #4162, you were already planning on having a fork of this crate, is there a specific reason why this change cannot live in that fork?

[Desiki-high]

Hi @Desiki-high, thank you for your contribution. Firecracker does not support ppc64le and riscv64, so I don't think having these two constants here is a very good idea, as it might send a wrong message about which platforms Firecracker supports. From my understanding of #4162, you were already planning on having a fork of this crate, is there a specific reason why this change cannot live in that fork?

Thanks for the review @roypat.
We only consider if the Firecracker needs this contribution, because this is useful for many projects which dependts on firecracker's snapshot crate. However it does lead to make a wrong message about which platforms Firecracker supports, so we will only use it in our fork crate. Thanks for your review again.