Re: [PATCH] x86/msr: Unify the real {rd,wr}msr() paths in guest_{rd,wr}msr()

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Wed, Jul 22, 2020 at 11:55:29AM +0100, Andrew Cooper wrote:
> Both the read and write side have commonalities which can be abstracted away.
> This also allows for additional safety in release builds, and slightly more
> helpful diagnostics in debug builds.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>

> ---
> CC: Jan Beulich <JBeulich@xxxxxxxx>
> CC: Wei Liu <wl@xxxxxxx>
> CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
> 
> I'm not a massive fan of the global scope want_rdmsr_safe boolean, but I can't
> think of a reasonable way to fix it without starting to use other
> flexibiltiies offered to us by C99.  (And to preempt the other question, an
> extra set of braces makes extremely confusing to read logic.)

The logic could be moved to a helper that takes a expected_safe or
some such parameter, but I think I prefer this approach.

Thanks, Roger.