OvmfPkg/VirtioMmioDeviceLib: Implement VIRTIO_DEVICE_PROTOCOL for VirtIo Devices over MMIO

Why is the virtio-mmio implementation of the protocol a library,
instead of a driver binary?
The UEFI driver model would encourage to create a virtio-mmio driver
instead of a library. But the reasons why I created a library are:

- A virtio-mmio driver would imply an additional protocol that would
probably have a single attribute field:

typedef struct {
  PHYSICAL_ADDRESS       BaseAddress;
} VIRTIO_MMIO_DEVICE_PROTOCOL;

- There is no (easy) way to scan the available VirtIo devices on a
platform. So, the UEFI firmware for this platform would need a driver
to produce instances for every virtio devices it wants to expose in
UEFI. A single call to a helper library (ie: VirtioMmioDeviceLib)
make the porting easier.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>

v5:
- typo fix in VirtioMmioInstallDevice() comment block
- plug MmioDevice leak in VirtioMmioUninstallDevice()
- return EFI_INVALID_PARAMETER in VirtioMmioGetQueueAddress() if
  QueueAddress is NULL
- VirtioMmioSetQueueSize(): fix return value (it's a status code)
- VirtioMmioSetPageSize(): check against EFI_PAGE_SIZE with "if" plus
  EFI_UNSUPPORTED, rather than ASSERT()
- VirtioMmioDeviceWrite(), VirtioMmioDeviceRead(): remove redundant
  (FieldSize > 8) checks
- VirtioMmioDeviceLib.inf: drop UefiDriverEntryPoint library dependency

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14965 6f19259b-4bc3-4df7-8a09-765794883524

OvmfPkg/Library/VirtioMmioDeviceLib/VirtioMmioDeviceLib.inf

@@ -0,0 +1,42 @@
+## @file
+# This driver produces the VirtIo Device Protocol instances for VirtIo Mmio
+# Device
+#
+# Copyright (C) 2013, ARM Ltd
+#
+# This program and the accompanying materials are licensed and made available
+# under the terms and conditions of the BSD License which accompanies this
+# distribution. The full text of the license may be found at
+# http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+# WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x00010006
+  BASE_NAME                      = VirtioMmioDeviceLib
+  FILE_GUID                      = 3b6ed966-b5d1-46a8-965b-867ff22d9c89
+  MODULE_TYPE                    = UEFI_DRIVER
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = VirtioMmioDeviceLib
+
+[Sources]
+  VirtioMmioDevice.c
+  VirtioMmioDeviceFunctions.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  OvmfPkg/OvmfPkg.dec
+
+[LibraryClasses]
+  BaseMemoryLib
+  DebugLib
+  IoLib
+  MemoryAllocationLib
+  UefiBootServicesTableLib
+  UefiLib
+
+[Protocols]
+  gVirtioDeviceProtocolGuid		## PRODUCES