[ipxe-devel] [PATCH v4 0/4] Implement virtio 1.0 support

[Ladi Prosek]

The goal here is to support booting from modern and transitional
virtio-net devices using the new virtio 1.0 protocol. The code
strives to comply with the virtio 1.0 spec and is heavily inspired
by the Linux kernel implementation.

Changes from v3:

* reverted the device initialization change, adjust_pci_device
  is called unconditionally again

Changes from v2:

* adjust_pci_device is called only if we actually use a bar,
  otherwise the device is left uninitialized

* vpm_reset now waits for the device to report status == 0

* added an explicit "case VIRTIO_PCI_REGION_PCI_CONFIG" and
  "default: assert(0)" to read/write functions (assert seems
  to be appropriate here, I haven't found a true crash or
  fail-fast function)

* now checking for a valid Ethernet MAC address as part of
  initialization - that includes the case where the device does
  not support VIRTIO_NET_F_MAC

* virtnet_open_modern fails if VIRTIO_F_VERSION_1 is not offered

* added a check for device ID < 0x1040 before falling back to
  the legacy probe

* new virtio_version field is used instead of ioaddr to tell if
  we're talking to the device using virtio 1.0

* comments and minor code changes

* rebased to latest master

Changes from v1:

* removed the packed attribute from virtio structures

* notification cap is now always mapped per queue - results in
  one more ioremap call but eliminates special case code

* only sizeof(struct virtio_net_config) instead of PAGE_SIZE
  of the device cap is mapped

* the config cap is now looked for and required

* vpm_ioread* and vpm_iowrite* support memory, port I/O, and PCI
  config space access through the config cap as a fallback, and
  are not declared inline anymore

* extra parameter is now used by virtnet_probe_modern instead of
  specific error code to indicate that a 1.0 device was found

* device initialization follows the spec - note that reset,
  ACKNOWLEDGE, and DRIVER happen in virtnet_probe_modern and the
  rest in virtnet_open_modern

* nits, comments, and typos here and there

 src/drivers/bus/pciextra.c     |  54 +++++--
 src/drivers/bus/virtio-pci.c   | 353 ++++++++++++++++++++++++++++++++++++++++-
 src/drivers/bus/virtio-ring.c  |  17 +-
 src/drivers/net/virtio-net.c   | 265 +++++++++++++++++++++++++++++--
 src/drivers/net/virtio-net.h   |  16 ++
 src/include/ipxe/errfile.h     |   1 +
 src/include/ipxe/pci.h         |   2 +
 src/include/ipxe/virtio-pci.h  | 207 ++++++++++++++++++++++++
 src/include/ipxe/virtio-ring.h |  14 +-
 9 files changed, 894 insertions(+), 35 deletions(-)