linux-coco.lists.linux.dev archive mirror
 help / color / mirror / Atom feed
From: Dov Murik <dovmurik@linux.ibm.com>
To: Borislav Petkov <bp@suse.de>
Cc: linux-efi@vger.kernel.org, Laszlo Ersek <lersek@redhat.com>,
	Ashish Kalra <ashish.kalra@amd.com>,
	Brijesh Singh <brijesh.singh@amd.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	James Morris <jmorris@namei.org>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	Andi Kleen <ak@linux.intel.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	James Bottomley <jejb@linux.ibm.com>,
	Tobin Feldman-Fitzthum <tobin@linux.ibm.com>,
	Jim Cadden <jcadden@ibm.com>,
	linux-coco@lists.linux.dev,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, Dov Murik <dovmurik@linux.ibm.com>
Subject: Re: [RFC PATCH v2 3/3] virt: Add sev_secret module to expose confidential computing secrets
Date: Tue, 29 Jun 2021 10:23:49 +0300	[thread overview]
Message-ID: <6e35f6db-9c5b-3c75-a66b-de1392295f6a@linux.ibm.com> (raw)
In-Reply-To: <YNojYBIwk0xCHQ0v@zn.tnic>



On 28/06/2021 22:30, Borislav Petkov wrote:
> On Mon, Jun 28, 2021 at 06:34:31PM +0000, Dov Murik wrote:
>> The new sev_secret module exposes the confidential computing secret area
>> via securityfs interface.
>>
>> When the module is loaded (and securityfs is mounted, typically under
>> /sys/kernel/security), an "sev_secret" directory is created in
>> securityfs.  In it, a file is created for each secret entry.  The name
>> of each such file is the GUID of the secret entry, and its content is
>> the secret data.
>>
>> This allows applications running in a confidential computing setting to
>> read secrets provided by the guest owner via a secure secret injection
>> mechanism (such as AMD SEV's LAUNCH_SECRET command).
>>
>> Removing (unlinking) files in the "sev_secret" directory will zero out
>> the secret in memory, and remove the filesystem entry.  If the module
>> is removed and loaded again, that secret will not appear in the
>> filesystem.
>>
>> Signed-off-by: Dov Murik <dovmurik@linux.ibm.com>
>> ---
>>  drivers/virt/Kconfig                 |   2 +
>>  drivers/virt/Makefile                |   1 +
>>  drivers/virt/sev_secret/Kconfig      |  11 +
>>  drivers/virt/sev_secret/Makefile     |   2 +
>>  drivers/virt/sev_secret/sev_secret.c | 298 +++++++++++++++++++++++++++
>>  5 files changed, 314 insertions(+)
>>  create mode 100644 drivers/virt/sev_secret/Kconfig
>>  create mode 100644 drivers/virt/sev_secret/Makefile
>>  create mode 100644 drivers/virt/sev_secret/sev_secret.c
> 
> Same question here: maybe have 
> 
> drivers/virt/coco/
> 
> and put all coco guest stuff in there.
> 

I agree, according to what comes up of the conversation we have in
replies to the cover letter.


>> diff --git a/drivers/virt/Kconfig b/drivers/virt/Kconfig
>> index 8061e8ef449f..c222cc625891 100644
>> --- a/drivers/virt/Kconfig
>> +++ b/drivers/virt/Kconfig
>> @@ -36,4 +36,6 @@ source "drivers/virt/vboxguest/Kconfig"
>>  source "drivers/virt/nitro_enclaves/Kconfig"
>>  
>>  source "drivers/virt/acrn/Kconfig"
>> +
>> +source "drivers/virt/sev_secret/Kconfig"
>>  endif
>> diff --git a/drivers/virt/Makefile b/drivers/virt/Makefile
>> index 3e272ea60cd9..0765e5418d1d 100644
>> --- a/drivers/virt/Makefile
>> +++ b/drivers/virt/Makefile
>> @@ -8,3 +8,4 @@ obj-y				+= vboxguest/
>>  
>>  obj-$(CONFIG_NITRO_ENCLAVES)	+= nitro_enclaves/
>>  obj-$(CONFIG_ACRN_HSM)		+= acrn/
>> +obj-y				+= sev_secret/
>> diff --git a/drivers/virt/sev_secret/Kconfig b/drivers/virt/sev_secret/Kconfig
>> new file mode 100644
>> index 000000000000..4505526b8ef1
>> --- /dev/null
>> +++ b/drivers/virt/sev_secret/Kconfig
>> @@ -0,0 +1,11 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +config AMD_SEV_SECRET_SECURITYFS
>> +	tristate "AMD SEV secret area securityfs support"
>> +	depends on EFI
> 
> That probably needs to depend on CONFIG_AMD_MEM_ENCRYPT - otherwise
> what's the point for it.
> 

But not if it's a generic driver that is useful for other confidential
computing implementations.  Consider some non-encrypting guest memory
isolation mechanism where the host can't read most guest pages; this
module might be useful there too.

Also, isn't it a bit weird to depend on CONFIG_AMD_MEM_ENCRYPT but not
use any of its APIs?


-Dov

  reply	other threads:[~2021-06-29  7:24 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-28 18:34 [RFC PATCH v2 0/3] Allow access to confidential computing secret area Dov Murik
2021-06-28 18:34 ` [RFC PATCH v2 1/3] efi/libstub: Copy " Dov Murik
2021-06-28 18:34 ` [RFC PATCH v2 2/3] efi: Reserve " Dov Murik
2021-06-28 20:40   ` Tom Lendacky
2021-06-29  6:04     ` Dov Murik
2021-06-28 18:34 ` [RFC PATCH v2 3/3] virt: Add sev_secret module to expose confidential computing secrets Dov Murik
2021-06-28 19:30   ` Borislav Petkov
2021-06-29  7:23     ` Dov Murik [this message]
2021-06-29 22:48       ` Borislav Petkov
2021-06-28 19:28 ` [RFC PATCH v2 0/3] Allow access to confidential computing secret area Borislav Petkov
2021-06-29  7:16   ` Dov Murik
2021-06-29 17:33     ` Borislav Petkov

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=6e35f6db-9c5b-3c75-a66b-de1392295f6a@linux.ibm.com \
    --to=dovmurik@linux.ibm.com \
    --cc=ak@linux.intel.com \
    --cc=ardb@kernel.org \
    --cc=ashish.kalra@amd.com \
    --cc=bp@suse.de \
    --cc=brijesh.singh@amd.com \
    --cc=dgilbert@redhat.com \
    --cc=jcadden@ibm.com \
    --cc=jejb@linux.ibm.com \
    --cc=jmorris@namei.org \
    --cc=lersek@redhat.com \
    --cc=linux-coco@lists.linux.dev \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=serge@hallyn.com \
    --cc=thomas.lendacky@amd.com \
    --cc=tobin@linux.ibm.com \
    --subject='Re: [RFC PATCH v2 3/3] virt: Add sev_secret module to expose confidential computing secrets' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).