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Diffstat (limited to 'OvmfPkg/Include/Library/VirtioLib.h')
| -rw-r--r-- | OvmfPkg/Include/Library/VirtioLib.h | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/OvmfPkg/Include/Library/VirtioLib.h b/OvmfPkg/Include/Library/VirtioLib.h new file mode 100644 index 0000000000..95657a7111 --- /dev/null +++ b/OvmfPkg/Include/Library/VirtioLib.h @@ -0,0 +1,187 @@ +/** @file
+
+ Declarations of utility functions used by virtio device drivers.
+
+ Copyright (C) 2012, Red Hat, Inc.
+
+ 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.
+
+**/
+
+#ifndef _VIRTIO_LIB_H_
+#define _VIRTIO_LIB_H_
+
+#include <Protocol/PciIo.h>
+#include <IndustryStandard/Virtio.h>
+
+/**
+
+ Write a word into Region 0 of the device specified by PciIo.
+
+ Region 0 must be an iomem region. This is an internal function for the
+ driver-specific VIRTIO_CFG_WRITE() macros.
+
+ @param[in] PciIo Target PCI device.
+
+ @param[in] FieldOffset Destination offset.
+
+ @param[in] FieldSize Destination field size, must be in { 1, 2, 4, 8 }.
+
+ @param[in] Value Little endian value to write, converted to UINT64.
+ The least significant FieldSize bytes will be used.
+
+
+ @return Status code returned by PciIo->Io.Write().
+
+**/
+EFIAPI
+EFI_STATUS
+VirtioWrite (
+ IN EFI_PCI_IO_PROTOCOL *PciIo,
+ IN UINTN FieldOffset,
+ IN UINTN FieldSize,
+ IN UINT64 Value
+ );
+
+
+/**
+
+ Read a word from Region 0 of the device specified by PciIo.
+
+ Region 0 must be an iomem region. This is an internal function for the
+ driver-specific VIRTIO_CFG_READ() macros.
+
+ @param[in] PciIo Source PCI device.
+
+ @param[in] FieldOffset Source offset.
+
+ @param[in] FieldSize Source field size, must be in { 1, 2, 4, 8 }.
+
+ @param[in] BufferSize Number of bytes available in the target buffer. Must
+ equal FieldSize.
+
+ @param[out] Buffer Target buffer.
+
+
+ @return Status code returned by PciIo->Io.Read().
+
+**/
+EFIAPI
+EFI_STATUS
+VirtioRead (
+ IN EFI_PCI_IO_PROTOCOL *PciIo,
+ IN UINTN FieldOffset,
+ IN UINTN FieldSize,
+ IN UINTN BufferSize,
+ OUT VOID *Buffer
+ );
+
+
+/**
+
+ Configure a virtio ring.
+
+ This function sets up internal storage (the guest-host communication area)
+ and lays out several "navigation" (ie. no-ownership) pointers to parts of
+ that storage.
+
+ Relevant sections from the virtio-0.9.5 spec:
+ - 1.1 Virtqueues,
+ - 2.3 Virtqueue Configuration.
+
+ @param[in] The number of descriptors to allocate for the
+ virtio ring, as requested by the host.
+
+ @param[out] Ring The virtio ring to set up.
+
+ @retval EFI_OUT_OF_RESOURCES AllocatePages() failed to allocate contiguous
+ pages for the requested QueueSize. Fields of
+ Ring have indeterminate value.
+
+ @retval EFI_SUCCESS Allocation and setup successful. Ring->Base
+ (and nothing else) is responsible for
+ deallocation.
+
+**/
+EFI_STATUS
+EFIAPI
+VirtioRingInit (
+ IN UINT16 QueueSize,
+ OUT VRING *Ring
+ );
+
+
+/**
+
+ Tear down the internal resources of a configured virtio ring.
+
+ The caller is responsible to stop the host from using this ring before
+ invoking this function: the VSTAT_DRIVER_OK bit must be clear in
+ VhdrDeviceStatus.
+
+ @param[out] Ring The virtio ring to clean up.
+
+**/
+VOID
+EFIAPI
+VirtioRingUninit (
+ IN OUT VRING *Ring
+ );
+
+
+/**
+
+ Append a contiguous buffer for transmission / reception via the virtio ring.
+
+ This function implements the following sections from virtio-0.9.5:
+ - 2.4.1.1 Placing Buffers into the Descriptor Table
+ - 2.4.1.2 Updating the Available Ring
+
+ Free space is taken as granted, since the individual drivers support only
+ synchronous requests and host side status is processed in lock-step with
+ request submission. It is the calling driver's responsibility to verify the
+ ring size in advance.
+
+ @param[in out] Ring The virtio ring to append the buffer to, as a
+ descriptor.
+
+ @param [in] BufferPhysAddr (Guest pseudo-physical) start address of the
+ transmit / receive buffer.
+
+ @param [in] BufferSize Number of bytes to transmit or receive.
+
+ @param [in] Flags A bitmask of VRING_DESC_F_* flags. The caller
+ computes this mask dependent on further buffers
+ to append and transfer direction.
+ VRING_DESC_F_INDIRECT is unsupported. The
+ VRING_DESC.Next field is always set, but the
+ host only interprets it dependent on
+ VRING_DESC_F_NEXT.
+
+ @param [in] HeadIdx The index identifying the head buffer (first
+ buffer appended) belonging to this same
+ request.
+
+ @param [in out] NextAvailIdx On input, the index identifying the next
+ descriptor available to carry the buffer. On
+ output, incremented by one, modulo 2^16.
+
+**/
+VOID
+EFIAPI
+AppendDesc (
+ IN OUT VRING *Ring,
+ IN UINTN BufferPhysAddr,
+ IN UINT32 BufferSize,
+ IN UINT16 Flags,
+ IN UINT16 HeadIdx,
+ IN OUT UINT16 *NextAvailIdx
+ );
+
+#endif // _VIRTIO_LIB_H_
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