Re: [PATCH v2] Linux VM workaround for Knights Landing A/D leak

[Nadav Amit]

Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> wrote:

> On 06/15/2016 01:04 PM, Nadav Amit wrote:
>> Be careful here. According to the SDM when invalidating a huge-page,
>> each 4KB page needs to be invalidated separately. In practice, when
>> Linux invalidates 2MB/1GB pages it performs a full TLB flush. The
>> full flush may not be required on knights landing, and specifically
>> for the workaround, but you should check.  
> 
> Where do you get that?  The SDM says: "they (TLB invalidation operations
> invalidate all TLB entries corresponding to the translation specified by
> the paging structures.”

You are absolutely correct. Last time I write something based on my
recollection of the SDM without re-reading again. Sorry.

Nadav