adding qemu devel and add Daniel and Erik from libvirt to keep them in the loop. On 10/29/2017 12:11 PM, Cornelia Huck wrote: > On Fri, 13 Oct 2017 13:38:45 -0400 > Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote: > >> Tony Krowiak (19): >> KVM: s390: SIE considerations for AP Queue virtualization >> KVM: s390: refactor crypto initialization >> s390/zcrypt: new AP matrix bus >> s390/zcrypt: create an AP matrix device on the AP matrix bus >> s390/zcrypt: base implementation of AP matrix device driver >> s390/zcrypt: register matrix device with VFIO mediated device >> framework >> KVM: s390: introduce AP matrix configuration interface >> s390/zcrypt: support for assigning adapters to matrix mdev >> s390/zcrypt: validate adapter assignment >> s390/zcrypt: sysfs interfaces supporting AP domain assignment >> s390/zcrypt: validate domain assignment >> s390/zcrypt: sysfs support for control domain assignment >> s390/zcrypt: validate control domain assignment >> KVM: s390: Connect the AP mediated matrix device to KVM >> s390/zcrypt: introduce ioctl access to VFIO AP Matrix driver >> KVM: s390: interface to configure KVM guest's AP matrix >> KVM: s390: validate input to AP matrix config interface >> KVM: s390: New ioctl to configure KVM guest's AP matrix >> s390/facilities: enable AP facilities needed by guest > > I'll try to summarize all of this in my own words, both to make sure I > understand the design correctly and to give others a different view on > this. > > [I'm completely disregarding control domains here.] > > On s390, we have cryptographic coprocessor cards, which are modeled on > Linux as devices on the AP bus. There's also a concept called domains, > which means an individual queue of a crypto device is basically 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) > > (The AP bus is a bit different for backwards compat.) > > 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 > (mostly) everything. > > 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 > node where mdev devices hang off. > > If you now want to give the tuples (4,1) and (4,2), you need to do the > following: > > - Unbind the (4,1) and (4,2) tuples from their ap bus driver. > - Bind the (4,1) and (4,2) tuples to the ap matrix driver. > - Create the mediated device. > - Assign card 4 and domains 1 and 2. > > QEMU will now simply consume the mediated device and things should work. > This is probably the shortest possible summary I can imagine. Tony can you double check if it matches your understanding as well?
