From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6781CD505 for ; Tue, 21 Mar 2023 18:50:17 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 5E65D203A3; Tue, 21 Mar 2023 18:50:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1679424615; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Gx1zHnKibOB/qZ9NAYIrNX0wXPKwNQLXbcqGgVodubY=; b=wVMwl9f6HH1Qr390iRu0UQb/fmpPtmUyyZFbevnA4xU5Bkp1PkOIU3MI3ljAfnf3POoQu4 VSEJENV8WtWOzAAGdhXHgi6M+fU1HCu4+Y7M/SyGQZvGqCC8m3nLVvVIFH7weLWew46HUT f0naiIhUXlKNpm4Sl9SvHxHZRcZCEII= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1679424615; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Gx1zHnKibOB/qZ9NAYIrNX0wXPKwNQLXbcqGgVodubY=; b=fhWRTiBacCKcF5/fErC+XC8UQ5GmR91L8YsUhcdwKT9pw5tUykNFHqwaRRXIWC51Y9otKg nvauJWm1dtSohGCg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 2C3E813451; Tue, 21 Mar 2023 18:50:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id ZhVQCWf8GWSeTAAAMHmgww (envelope-from ); Tue, 21 Mar 2023 18:50:15 +0000 Date: Tue, 21 Mar 2023 19:50:13 +0100 From: =?iso-8859-1?Q?J=F6rg_R=F6del?= To: "Dr. David Alan Gilbert" Cc: James Bottomley , amd-sev-snp@lists.suse.com, linux-coco@lists.linux.dev, kvm@vger.kernel.org Subject: Re: [ANNOUNCEMENT] COCONUT Secure VM Service Module for SEV-SNP Message-ID: References: <66eee693371c11bbd2173ad5d91afc740aa17b46.camel@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Mar 21, 2023 at 05:48:38PM +0000, Dr. David Alan Gilbert wrote: > I'm curious why you're doing isolation using ring-3 stuff rather than > another VMPL level? Two reasons: 1) CPL switch is much cheaper than VMPL switch 2) CPLs allow to isolate different services within the same VMPL. Having services run at, say, VMPL1 on CPL-0 will allow all services on VMPL1 to access each others memory. Regards, -- Jörg Rödel jroedel@suse.de SUSE Software Solutions Germany GmbH Frankenstraße 146 90461 Nürnberg Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman