Re: [PATCH v2 4/4] virt: Add sev_secret module to expose confidential computing secrets

* Dave Hansen (dave.hansen@intel.com) wrote:

On 10/6/21 11:18 PM, Dov Murik wrote:

quoted

+static int sev_secret_map_area(void)
+{
+	struct sev_secret *s = sev_secret_get();
+	struct linux_efi_coco_secret_area *secret_area;
+	u32 secret_area_size;
+
+	if (efi.coco_secret == EFI_INVALID_TABLE_ADDR) {
+		pr_err("Secret area address is not available\n");
+		return -EINVAL;
+	}
+
+	secret_area = memremap(efi.coco_secret, sizeof(*secret_area), MEMREMAP_WB);
+	if (secret_area == NULL) {
+		pr_err("Could not map secret area header\n");
+		return -ENOMEM;
+	}

There doesn't seem to be anything truly SEV-specific in here at all.
Isn't this more accurately called "efi_secret" or something?  What's to
prevent Intel or an ARM vendor from implementing this?

I don't think anything; although the last discussion I remember on list
with Intel was that Intel preferred some interface with an ioctl to read
the secrets and stuff.  I'm not quite sure if the attestation/secret
delivery order makes sense with TDX, but if it does, then if you could
persuade someone to standardise on this it would be great.

Dave

-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK