From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v10 00/26] guest dedicated crypto adapters Date: Mon, 24 Sep 2018 12:45:38 -0400 Message-ID: References: <1536781396-13601-1-git-send-email-akrowiak@linux.vnet.ibm.com> <20180924134931.6c67a3d2.cohuck@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180924134931.6c67a3d2.cohuck@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Cornelia Huck , Tony Krowiak Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, borntraeger@de.ibm.com, kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com, alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com, thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com, fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com, frankja@linux.ibm.com List-ID: On 09/24/2018 07:49 AM, Cornelia Huck wrote: > On Wed, 12 Sep 2018 15:42:50 -0400 > Tony Krowiak wrote: > >> Abstract: >> ======== >> >> On s390, we have cryptographic coprocessor cards, which are modeled on >> Linux as devices on the AP bus. Each card can be partitioned into domains >> which can be thought of as a set of hardware registers for processing >> crypto commands. Crypto commands are sent to a specific domain within a >> card is via a queue which is identified as a (card,domain) tuple. We model >> this something like the following (assuming we have access to cards 3 and >> 4 and domains 1 and 2): >> >> AP -> card3 -> queue (3,1) >> -> queue (3,2) >> -> card4 -> queue (4,1) >> -> queue (4,2) >> >> If we want to virtualize this, we can use a feature provided by the >> hardware. We basically attach a satellite control block to our main >> hardware virtualization control block and the hardware takes care of >> most of the rest. >> >> For this control block, we don't specify explicit tuples, but a list of >> cards and a list of domains. The guest will get access to the cross >> product. >> >> Because of this, we need to take care that the lists provided to >> different guests don't overlap; i.e., we need to enforce sane >> configurations. Otherwise, one guest may get access to things like >> secret keys for another guest. >> >> The idea of this patch set is to introduce a new device, the matrix >> device. This matrix device hangs off a different root and acts as the >> parent node for mdev devices. >> >> If you now want to give the tuples (4,1) and (4,2), you need to do the >> following: >> >> - Make sure the queues (4,1) and (4,2) belong to vfio_ap (see patches >> #5 and #6) >> - Create the mediated device. >> - Assign card 4 and domains 1 and 2 to the mediated device >> - Optionally activate the mediated device. >> >> QEMU will now simply consume the mediated device and things should work. >> >> For a complete description of the architecture and concepts underlying >> the design, see the Documentation/s390/vfio-ap.txt file included with this >> patch set. > > I did not spot anything major, and if v11 addresses the issues raised > by various reviewers I don't see why it should not be merged (interface > looks sane). I skipped looking at the vsie stuff, though ;) I think David has that covered. >