Re: [PATCH for-4.14] x86/ucode: Fix errors with start/end_update()

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

On Mon, Jun 01, 2020 at 03:57:55PM +0100, Andrew Cooper wrote:
> c/s 9267a439c "x86/ucode: Document the behaviour of the microcode_ops hooks"
> identified several poor behaviours of the start_update()/end_update_percpu()
> hooks.
> 
> AMD have subsequently confirmed that OSVW don't, and are not expected to,
> change across a microcode load, rendering all of this complexity unecessary.

Is there a reference to some AMD PM or similar document that can be
added here for completeness?

> Instead of fixing up the logic to not leave the OSVW state reset in a number
> of corner cases, delete the logic entirely.  This in turn allows for the
> removal of the poorly-named 'start_update' parameter to
> microcode_update_one().
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

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

Thanks, Roger.