• Tony Krowiak's avatar
    s390: vfio-ap: base implementation of VFIO AP device driver · 1fde5734
    Tony Krowiak authored
    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.
    
      3. A lack of older systems on which to test older devices.
    
      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: default avatarTony Krowiak <akrowiak@linux.ibm.com>
    Reviewed-by: default avatarHalil Pasic <pasic@linux.ibm.com>
    Tested-by: default avatarMichael Mueller <mimu@linux.ibm.com>
    Tested-by: default avatarFarhan Ali <alifm@linux.ibm.com>
    Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
    Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
    Message-Id: <20180925231641.4954-5-akrowiak@linux.vnet.ibm.com>
    Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
    1fde5734
Makefile 623 Bytes