Re: [PATCH][4.15] x86/shadow: replace bogus return path in shadow_get_page_from_l1e()

[Jan Beulich <jbeulich@xxxxxxxx>]

On 26.02.2021 16:08, Jan Beulich wrote:
> Prior to be640b1800bb ("x86: make get_page_from_l1e() return a proper
> error code") a positive return value did indicate an error. Said commit
> failed to adjust this return path, but luckily the only caller has
> always been inside a shadow_mode_refcounts() conditional.
> 
> Subsequent changes caused 1 to end up at the default (error) label in
> the caller's switch() again, but the returning of 1 (== _PAGE_PRESENT)
> is still rather confusing here, and a latent risk.

The confusion on my part was so significant that I screwed up
the shadow mode fix for "VMX: use a single, global APIC access
page" (which turned out to be necessary) initially. Hence my
proposing this for 4.15. I'm on the edge at this point whether
I'd even consider this a backporting candidate.

Jan