[Qemu-devel] [RFC v6-based v1 0/5] refine mdev framework

[Jike Song]

This patchset is based on NVidia's "Add Mediated device support" series, 
version 6:

        http://www.spinics.net/lists/kvm/msg136472.html


Background:

        The patchset from NVidia introduced the Mediated Device support to
        Linux/VFIO. With that series, one can create virtual devices (supporting
        by underlying physical device and vendor driver), and assign them to
        userspace like QEMU/KVM, in the same way as device assignment via VFIO.

        Based on that, NVidia and Intel implemented their vGPU solutions, IBM
        implemented its CCW pass-through.  However, there are limitations
        imposed by current (v6 in particular) mdev framework: the mdev must be
        represented as a PCI device, several vfio capabilities such as
        sparse mmap are not possible, and so forth.

        This series aims to address above limitations and simplify the 
implementation.


Key Changes:

        - An independent "struct device" was introduced to parent_device, thus
          a hierarchy in driver core is formed with physical device, parent 
device
          and mdev device;

        - Leveraging the mechanism and APIs provided by Linux driver core, it
          is now safe to remove all refcnts and locks;

        - vfio_mpci (later renamed to vfio_mdev) was made BUS-agnostic: all
          PCI-specific logic was removed, accesses from userspace are now
          passed to vendor driver directly, thus guaranteed that full VFIO
          capabilities provided: e.g. dynamic regions, sparse mmap, etc.;

          With vfio_mdev being BUS-agnostic, it is enough to have only one
          driver for all mdev devices;

        - UUID was removed from the interface between mdev and vendor driver;


TODO

        remove mdev stuff from vfio.h
        update doc



Jike Song (3):
  mdev: remove uuid from parent_ops
  vfio_mpci: remove PCI-specific logic
  rename 'vfio_mpci' to 'vfio_mdev' since it is now BUS-agnostic

Xiao Guangrong (2):
  mdev: create separate device for parent_device
  mdev: drop management information and utilize driver-core instead

 drivers/vfio/mdev/Kconfig           |  10 +-
 drivers/vfio/mdev/Makefile          |   5 +-
 drivers/vfio/mdev/mdev_core.c       | 483 +++++---------------------------
 drivers/vfio/mdev/mdev_private.h    |   9 +-
 drivers/vfio/mdev/mdev_sysfs.c      |  82 ++----
 drivers/vfio/mdev/vfio_mdev.c       | 168 +++++++++++
 drivers/vfio/mdev/vfio_mpci.c       | 536 ------------------------------------
 drivers/vfio/pci/vfio_pci_private.h |   6 +
 include/linux/mdev.h                |  87 ++----
 include/linux/vfio.h                |   7 -
 10 files changed, 302 insertions(+), 1091 deletions(-)
 create mode 100644 drivers/vfio/mdev/vfio_mdev.c
 delete mode 100644 drivers/vfio/mdev/vfio_mpci.c

-- 
1.9.1