On Sun, Feb 28, 2021 at 05:15:22PM -0800, Michael Kelley wrote:

To support Linux guests on Hyper-V on multiple architectures, the original
approach factored out all differences between Hyper-V on x86/x64 and
Hyper-V on ARM64 into functions or #defines under arch/x86 and
arch/arm64. Some of these differences are truly related to the
architecture, but others are more properly treated as Linux OS
differences or just quirks in Hyper-V. Feedback from Arnd Bergmann[1]
recommended that differences other than architecture should be
incorporated into the architecture independent Hyper-V code. Each
difference can be handled with conditions specific to the difference
instead of tying it to the broader x86/x64 vs. ARM64. This approach
reduces the amount of code under arch/x86 and arch/arm64 and keeps
the non-architectural differences localized and more easily understood.

This patch set implements the new approach by changing the interface
between the architecture independent code and the architecture dependent
code for x86/x64. The patches move code from arch/x86 to the
architecture independent Hyper-V code whenever possible, and add
architecture independent support needed by other architectures like
ARM64.  No functionality is changed for x86/x64.  A subsequent patch
set will provide the Hyper-V support code under arch/arm64.

This patch set results in an increase in lines of code (though some
of the increase is additional comments).  But the lines needed under
arch/arm64 in the upcoming patch set is significantly reduced, resulting
in a net decrease of about 125 lines.

[1] https://lore.kernel.org/lkml/CAK8P3a1hDBVembCd+6=ENUWYFz=72JBTFMrKYZ2aFd+_Q04F+g@mail.gmail.com/ (local)

This series looks good to me.

Given this series touches mostly Hyper-V code. I will be taking this it
via hyperv-next once the last two patches are reviewed.

Wei.