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Message-ID: <1035fbeb-3f03-e6e6-881d-fdf71eedd177@linux.ibm.com>
Date:   Wed, 2 Feb 2022 12:55:10 +0200
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Subject: Re: [PATCH v7 3/5] virt: Add efi_secret module to expose confidential
 computing secrets
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To:     Gerd Hoffmann <kraxel@redhat.com>
Cc:     linux-efi@vger.kernel.org, Borislav Petkov <bp@suse.de>,
        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>,
        Greg KH <gregkh@linuxfoundation.org>,
        Andrew Scull <ascull@google.com>,
        Dave Hansen <dave.hansen@intel.com>,
        "Dr. David Alan Gilbert" <dgilbert@redhat.com>,
        Lenny Szubowicz <lszubowi@redhat.com>,
        Peter Gonda <pgonda@google.com>,
        James Bottomley <jejb@linux.ibm.com>,
        Tobin Feldman-Fitzthum <tobin@linux.ibm.com>,
        Jim Cadden <jcadden@ibm.com>,
        Daniele Buono <dbuono@linux.vnet.ibm.com>,
        linux-coco@lists.linux.dev, linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org, Dov Murik <dovmurik@linux.ibm.com>
References: <20220201124413.1093099-1-dovmurik@linux.ibm.com>
 <20220201124413.1093099-4-dovmurik@linux.ibm.com>
 <20220202084512.2errjezf7ugrhntr@sirius.home.kraxel.org>
From:   Dov Murik <dovmurik@linux.ibm.com>
In-Reply-To: <20220202084512.2errjezf7ugrhntr@sirius.home.kraxel.org>
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On 02/02/2022 10:45, Gerd Hoffmann wrote:
>   Hi,
> 
>> +	s->coco_dir = NULL;
>> +	s->fs_dir = NULL;
>> +	memset(s->fs_files, 0, sizeof(s->fs_files));
>> +
>> +	dent = securityfs_create_dir("coco", NULL);
>> +	if (IS_ERR(dent)) {
>> +		pr_err("Error creating coco securityfs directory entry err=%ld\n", PTR_ERR(dent));
>> +		return PTR_ERR(dent);
>> +	}
>> +	s->coco_dir = dent;
>> +
>> +	dent = securityfs_create_dir("efi_secret", s->coco_dir);
>> +	if (IS_ERR(dent)) {
>> +		pr_err("Error creating efi_secret securityfs directory entry err=%ld\n",
>> +		       PTR_ERR(dent));
>> +		return PTR_ERR(dent);
>> +	}
>> +	d_inode(dent)->i_op = &efi_secret_dir_inode_operations;
>> +	s->fs_dir = dent;
> 
> Why have two levels of subdirectories here?  Do we expect more users for
> the coco/ directory?
> 

In the RFCv2 of this series Borislav Petkov suggested [1] adding a
"coco/" directory (originally it was "<securityfs>/sev_secret"); he
envisioned that other coco platforms (SNP, TDX) might want to expose
something to userspace via filesystem.

[1] https://lore.kernel.org/linux-coco/YNoiydeow+ftvfYX@zn.tnic/


> See also the naming discussion in the cover letter sub-thread.

Yep, following.


Thanks,
Dov