Re: [PATCHv15 00/17] Linear Address Masking enabling

[Kirill A. Shutemov]

On Tue, Jan 24, 2023 at 02:01:58PM +0300, Kirill A. Shutemov wrote:
> On Mon, Jan 23, 2023 at 06:07:20PM -0800, Linus Torvalds wrote:
> > On Mon, Jan 23, 2023 at 2:05 PM Kirill A. Shutemov
> > <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
> > >
> > > Linear Address Masking[1] (LAM) modifies the checking that is applied to
> > > 64-bit linear addresses, allowing software to use of the untranslated
> > > address bits for metadata.
> > >
> > > The capability can be used for efficient address sanitizers (ASAN)
> > > implementation and for optimizations in JITs and virtual machines.
> > >
> > > The patchset brings support for LAM for userspace addresses. Only LAM_U57 at
> > > this time.
> > 
> > I didn't react to anything objectionable in the series.
> > 
> > My only reaction was actually to ask "when / what CPU cores are
> > expected to support this feature"?
> > 
> > Maybe it was mentioned somewhere, and I'm just blind and not finding
> > it.  But even the "Instruction Set Extensions and Future Features"
> > paper seems to just be talking about the CPUID bits, not about any
> > actual "this is when we expect it".
> 
> There's no announced CPUs that have the feature. And it is above my pay
> grade to disclose anything beyond that.

I've asked around and if everything goes well it will be available early
2024.

-- 
  Kiryl Shutsemau / Kirill A. Shutemov