Re: [PATCH v10 04/26] s390: vfio-ap: base implementation of VFIO AP device driver

Tony Krowiak
2018-09-20T15:53:19Z

On 09/20/2018 11:31 AM, Cornelia Huck wrote:
> On Wed, 12 Sep 2018 15:42:54 -0400
> Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
>
>> From: Tony Krowiak <akrowiak@linux.ibm.com>
>>
>> Introduces a new AP device driver. This device driver
>> is built on the VFIO mediated device framework. The framework
>> provides sysfs interfaces that facilitate passthrough
>> access by guests to devices installed on the linux host.
>>
>> The VFIO AP device driver will serve two purposes:
>>
>> 1. Provide the interfaces to reserve AP devices for exclusive
>> use by KVM guests. This is accomplished by unbinding the
>> devices to be reserved for guest usage from the zcrypt
>> device driver and binding them to the VFIO AP device driver.
>>
>> 2. Implements the functions, callbacks and sysfs attribute
>> interfaces required to create one or more VFIO mediated
>> devices each of which will be used to configure the AP
>> matrix for a guest and serve as a file descriptor
>> for facilitating communication between QEMU and the
>> VFIO AP device driver.
>>
>> When the VFIO AP device driver is initialized:
>>
>> * It registers with the AP bus for control of type 10 (CEX4
>> and newer) AP queue devices. This limitation was imposed
>> due to:
>>
>> 1. A desire to keep the code as simple as possible;
>>
>> 2. Some older models are no longer supported by the kernel
>> and others are getting close to end of service.
>>
>> The probe and remove callbacks will be provided to support
>> the binding/unbinding of AP queue devices to/from the VFIO
>> AP device driver.
>>
>> * Creates a matrix device, /sys/devices/vfio_ap/matrix,
>> to serve as the parent of the mediated devices created, one
>> for each guest, and to hold the APQNs of the AP devices bound to
>> the VFIO AP device driver.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>> Tested-by: Michael Mueller <mimu@linux.ibm.com>
>> Tested-by: Farhan Ali <alifm@linux.ibm.com>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Christian's S-o-b looks a bit odd here; OTOH, it's probably him anyway
> who will queue the patches in the end :)

It went in there when Christian submitted the patch series in my absence
back in
July while I was on vacation. I wasn't aware it was in the actual commit
message,
so it never got removed. I'll remove it if a v11 needs to be submitted.

>
>> ---
>> MAINTAINERS | 10 +++
>> arch/s390/Kconfig | 11 +++
>> drivers/iommu/Kconfig | 8 ++
>> drivers/s390/crypto/Makefile | 4 +
>> drivers/s390/crypto/vfio_ap_drv.c | 134 +++++++++++++++++++++++++++++++++
>> drivers/s390/crypto/vfio_ap_private.h | 34 ++++++++
>> 6 files changed, 201 insertions(+), 0 deletions(-)
>> create mode 100644 drivers/s390/crypto/vfio_ap_drv.c
>> create mode 100644 drivers/s390/crypto/vfio_ap_private.h
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>