[PATCH v2 10/23] OvmfPkg/VirtioLib: add VirtioMapAllBytesInSharedBuffer() helper function

[Brijesh Singh <brijesh.singh@amd.com>]

The function can be used for mapping the system physical address to virtio
device address using VIRTIO_DEVICE_PROTOCOL.MapSharedBuffer (). The
function helps centralizing error handling, and it allows caller to pass
in constant or other evaluated expression for NumberOfBytes.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 OvmfPkg/Include/Library/VirtioLib.h   | 44 +++++++++++
 OvmfPkg/Library/VirtioLib/VirtioLib.c | 78 ++++++++++++++++++++
 2 files changed, 122 insertions(+)

diff --git a/OvmfPkg/Include/Library/VirtioLib.h b/OvmfPkg/Include/Library/VirtioLib.h
index 5badfb32917f..d8f24a5d68b1 100644
--- a/OvmfPkg/Include/Library/VirtioLib.h
+++ b/OvmfPkg/Include/Library/VirtioLib.h
@@ -3,6 +3,7 @@
   Declarations of utility functions used by virtio device drivers.
 
   Copyright (C) 2012-2016, Red Hat, Inc.
+  Copyright (C) 2017, AMD Inc, All rights reserved.<BR>
 
   This program and the accompanying materials are licensed and made available
   under the terms and conditions of the BSD License which accompanies this
@@ -235,4 +236,47 @@ Virtio10WriteFeatures (
   IN OUT UINT8                  *DeviceStatus
   );
 
+/**
+  Provides the virtio device address required to access system memory from a
+  DMA bus master.
+
+  @param[in]     This             The protocol instance pointer.
+
+  @param[in]     Operation        Indicates if the bus master is going to
+                                  read or write to system memory.
+
+  @param[in]     HostAddress      The system memory address to map to shared
+                                  buffer address.
+
+  @param[in,out] NumberOfBytes    On input the number of bytes to map.
+                                  On output the number of bytes that were
+                                  mapped.
+
+  @param[out]    DeviceAddress    The resulting shared map address for the
+                                  bus master to access the hosts HostAddress.
+
+  @param[out]    Mapping          A resulting taken to pass to
+                                  VIRTIO_UNMAP_SHARED.
+
+
+  @retval EFI_SUCCESS             The range was mapped for the returned
+                                  NumberOfBytes.
+  @retval EFI_UNSUPPORTED         The HostAddress cannot be mapped as a
+                                  common buffer.
+  @retval EFI_INVALID_PARAMETER   One or more parameters are invalid.
+  @retval EFI_OUT_OF_RESOURCES    The request could not be completed due to
+                                  a lack of resources.
+  @retval EFI_DEVICE_ERROR        The system hardware could not map the
+                                  requested address.
+**/
+EFI_STATUS
+EFIAPI
+VirtioMapAllBytesInSharedBuffer (
+  IN  VIRTIO_DEVICE_PROTOCOL  *VirtIo,
+  IN  VIRTIO_MAP_OPERATION    Operation,
+  IN  VOID                    *HostAddress,
+  IN  UINTN                   NumberOfBytes,
+  OUT EFI_PHYSICAL_ADDRESS    *DeviceAddress,
+  OUT VOID                    **Mapping
+  );
 #endif // _VIRTIO_LIB_H_
diff --git a/OvmfPkg/Library/VirtioLib/VirtioLib.c b/OvmfPkg/Library/VirtioLib/VirtioLib.c
index 845f206369a3..ac0ae97f3692 100644
--- a/OvmfPkg/Library/VirtioLib/VirtioLib.c
+++ b/OvmfPkg/Library/VirtioLib/VirtioLib.c
@@ -4,6 +4,7 @@
 
   Copyright (C) 2012-2016, Red Hat, Inc.
   Portion of Copyright (C) 2013, ARM Ltd.
+  Copyright (C) 2017, AMD Inc, All rights reserved.<BR>
 
   This program and the accompanying materials are licensed and made available
   under the terms and conditions of the BSD License which accompanies this
@@ -414,3 +415,80 @@ Virtio10WriteFeatures (
 
   return Status;
 }
+
+/**
+  Provides the virtio device address required to access system memory from a
+  DMA bus master.
+
+  @param[in]     This             The protocol instance pointer.
+
+  @param[in]     Operation        Indicates if the bus master is going to
+                                  read or write to system memory.
+
+  @param[in]     HostAddress      The system memory address to map to shared
+                                  buffer address.
+
+  @param[in,out] NumberOfBytes    On input the number of bytes to map.
+                                  On output the number of bytes that were
+                                  mapped.
+
+  @param[out]    DeviceAddress    The resulting shared map address for the
+                                  bus master to access the hosts HostAddress.
+
+  @param[out]    Mapping          A resulting taken to pass to
+                                  VIRTIO_UNMAP_SHARED.
+
+
+  @retval EFI_SUCCESS             The range was mapped for the returned
+                                  NumberOfBytes.
+  @retval EFI_UNSUPPORTED         The HostAddress cannot be mapped as a
+                                  common buffer.
+  @retval EFI_INVALID_PARAMETER   One or more parameters are invalid.
+  @retval EFI_OUT_OF_RESOURCES    The request could not be completed due to
+                                  a lack of resources.
+  @retval EFI_DEVICE_ERROR        The system hardware could not map the
+                                  requested address.
+**/
+EFI_STATUS
+EFIAPI
+VirtioMapAllBytesInSharedBuffer (
+  IN  VIRTIO_DEVICE_PROTOCOL  *VirtIo,
+  IN  VIRTIO_MAP_OPERATION    Operation,
+  IN  VOID                    *HostAddress,
+  IN  UINTN                   NumberOfBytes,
+  OUT EFI_PHYSICAL_ADDRESS    *DeviceAddress,
+  OUT VOID                    **Mapping
+  )
+{
+  EFI_STATUS            Status;
+  VOID                  *MapInfo;
+  UINTN                 Size;
+  EFI_PHYSICAL_ADDRESS  PhysicalAddress;
+
+  Size = NumberOfBytes;
+  Status = VirtIo->MapSharedBuffer (
+                     VirtIo,
+                     Operation,
+                     HostAddress,
+                     &Size,
+                     &PhysicalAddress,
+                     &MapInfo
+                     );
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  if (Size < NumberOfBytes) {
+    goto Failed;
+  }
+
+  *Mapping = MapInfo;
+  *DeviceAddress = PhysicalAddress;
+
+  return EFI_SUCCESS;
+
+Failed:
+  VirtIo->UnmapSharedBuffer (VirtIo, MapInfo);
+  *Mapping = NULL;
+  return EFI_OUT_OF_RESOURCES;
+}
-- 
2.7.4