Re: [RFC PATCH v2 04/20] x86: Secure Memory Encryption (SME) support

From	Andy Lutomirski <luto@amacapital.net>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH v2 04/20] x86: Secure Memory Encryption (SME) support
Date	2016-08-30 17:00 +0200
Message-ID	<sbSG5-6ew-23@gated-at.bofh.it> (permalink)
References	<s9VRL-5gY-3@gated-at.bofh.it> <sa2zT-1n5-3@gated-at.bofh.it> <sa2zT-1n5-1@gated-at.bofh.it> <sbSG5-6ew-25@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Aug 30, 2016 6:34 AM, "Tom Lendacky" <thomas.lendacky@amd.com> wrote:
>
> On 08/25/2016 08:04 AM, Thomas Gleixner wrote:
> > On Mon, 22 Aug 2016, Tom Lendacky wrote:
> >
> >> Provide support for Secure Memory Encryption (SME). This initial support
> >> defines the memory encryption mask as a variable for quick access and an
> >> accessor for retrieving the number of physical addressing bits lost if
> >> SME is enabled.
> >
> > What is the reason that this needs to live in assembly code?
>
> In later patches this code is expanded and deals with a lot of page
> table manipulation, cpuid/rdmsr instructions, etc. and so I thought it
> was best to do it this way.

None of that sounds like it needs to be in asm, though.

I, at least, have a strong preference for minimizing the amount of asm
in the low-level arch code.

--Andy

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

Re: [RFC PATCH v2 04/20] x86: Secure Memory Encryption (SME)  support Thomas Gleixner <tglx@linutronix.de> - 2016-08-25 15:10 +0200
  Re: [RFC PATCH v2 04/20] x86: Secure Memory Encryption (SME) support Andy Lutomirski <luto@amacapital.net> - 2016-08-30 17:00 +0200

csiph-web