All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dave Hansen <dave.hansen@intel.com>
To: Borislav Petkov <bp@alien8.de>,
	Martin Fernandez <martin.fernandez@eclypsium.com>
Cc: Richard Hughes <hughsient@gmail.com>,
	linux-efi@vger.kernel.org,
	Platform Driver <platform-driver-x86@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, X86 ML <x86@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	ardb@kernel.org, dvhart@infradead.org, andy@infradead.org,
	Greg KH <gregkh@linuxfoundation.org>,
	rafael@kernel.org, Daniel Gutson <daniel.gutson@eclypsium.com>
Subject: Re: [PATCH v2 0/5] [RFC] x86: Export information about hardware memory encryption to sysfs
Date: Thu, 28 Oct 2021 11:17:48 -0700	[thread overview]
Message-ID: <aa030d5a-0cb1-6cac-b04e-7ab1c3624658@intel.com> (raw)
In-Reply-To: <YXrnkxgdjWbcPlJA@zn.tnic>

On 10/28/21 11:10 AM, Borislav Petkov wrote:
>> and even if it is activated you will need to be sure that you are
>> storing your data in a region flagged with this new attribute.
> Can you have a system where some of the memory is crypto-capable and
> some of it is not? I've never heard about such a system. At least, on
> AMD SME, all your memory gets encrypted...

Yes, unfortunately.

As an example, an Intel system with TME support will *not* encrypt data
going to Optane (aka. pmem).  That pmem might be online and being used
by the kernel as normal RAM with my fancy "kmem" DAX driver.

CXL devices will have normal RAM on them, be exposed as "System RAM" and
they won't have encryption capabilities.  I think these devices were
probably the main motivation for EFI_MEMORY_CPU_CRYPTO.

  reply	other threads:[~2021-10-28 18:17 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-27 19:55 [PATCH v2 0/5] [RFC] x86: Export information about hardware memory encryption to sysfs Martin Fernandez
2021-10-27 19:55 ` [PATCH v2 1/5] Extend memblock to support memory encryption Martin Fernandez
2021-10-27 19:55 ` [PATCH v2 2/5] Extend pg_data_t to hold information about " Martin Fernandez
2021-10-27 19:55 ` [PATCH v2 3/5] Extend e820_table " Martin Fernandez
2021-10-27 19:55 ` [PATCH v2 4/5] Mark e820_entries as crypto capable from EFI memmap Martin Fernandez
2021-10-27 19:55 ` [PATCH v2 5/5] Show in sysfs if a memory node is able to do memory encryption Martin Fernandez
2021-10-28 18:09   ` Dave Hansen
2021-10-27 20:21 ` [PATCH v2 0/5] [RFC] x86: Export information about hardware memory encryption to sysfs Dave Hansen
2021-10-28 14:28   ` Martin Fernandez
2021-10-28 14:55     ` Borislav Petkov
2021-10-28 16:03       ` Richard Hughes
2021-10-28 16:35         ` Borislav Petkov
2021-10-28 17:39           ` Martin Fernandez
2021-10-28 18:10             ` Borislav Petkov
2021-10-28 18:17               ` Dave Hansen [this message]
2021-10-29 17:08             ` Dave Hansen
2021-11-01 18:12               ` Martin Fernandez
2021-11-01 20:10               ` Martin Fernandez
2021-10-29 13:14           ` Richard Hughes
2021-10-28 15:24     ` Dave Hansen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=aa030d5a-0cb1-6cac-b04e-7ab1c3624658@intel.com \
    --to=dave.hansen@intel.com \
    --cc=andy@infradead.org \
    --cc=ardb@kernel.org \
    --cc=bp@alien8.de \
    --cc=daniel.gutson@eclypsium.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=dvhart@infradead.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=hpa@zytor.com \
    --cc=hughsient@gmail.com \
    --cc=linux-efi@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=martin.fernandez@eclypsium.com \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=platform-driver-x86@vger.kernel.org \
    --cc=rafael@kernel.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.