On 03.02.2022 19:10, Andrew Cooper wrote:
> It was Xen 4.14 where CPUID data was added to the migration stream, and 4.13
> that we need to worry about with regards to compatibility. Xen 4.12 isn't
> relevant.
>
> Expand and correct the commentary.
>
> Fixes: 111c8c33a8a1 ("x86/cpuid: do not expand max leaves on restore")
But doesn't this commit amend 685e922d6f30 ("tools/libxc: Rework
xc_cpuid_apply_policy() to use {get,set}_cpu_policy()"), which is
where DEF_MAX_* disappeared? That was a 4.13 change, and iirc that
was also why the commit above moved the 4.13/4.14 boundary related
comment from outside of the if() to inside it.
While looking at this, wasn't Roger's change incomplete, in that
for Intel the extended leaf upper bound was 0x80000008 in 4.12?
Jan
