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

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 01/06/2020 16:48, Roger Pau Monné wrote:
> 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?

Not at the moment.  (I'm attempting to solve this...)

>
>> 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,

~Andrew