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/** @file
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>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#ifndef _VIRTIO_LIB_H_
#define _VIRTIO_LIB_H_
#include <Protocol/VirtioDevice.h>
#include <IndustryStandard/Virtio.h>
/**
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] VirtIo The virtio device which will use the ring.
@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.
@return Status codes propagated from
VirtIo->AllocateSharedPages().
@retval EFI_SUCCESS Allocation and setup successful. Ring->Base
(and nothing else) is responsible for
deallocation.
**/
EFI_STATUS
EFIAPI
VirtioRingInit (
IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
IN UINT16 QueueSize,
OUT VRING *Ring
);
/**
Map the ring buffer so that it can be accessed equally by both guest
and hypervisor.
@param[in] VirtIo The virtio device instance.
@param[in] Ring The virtio ring to map.
@param[out] RingBaseShift A resulting translation offset, to be
passed to VirtIo->SetQueueAddress().
@param[out] Mapping A resulting token to pass to
VirtIo->UnmapSharedBuffer().
@return Status code from VirtIo->MapSharedBuffer()
**/
EFI_STATUS
EFIAPI
VirtioRingMap (
IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
IN VRING *Ring,
OUT UINT64 *RingBaseShift,
OUT VOID **Mapping
);
/**
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[in] VirtIo The virtio device which was using the ring.
@param[out] Ring The virtio ring to clean up.
**/
VOID
EFIAPI
VirtioRingUninit (
IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
IN OUT VRING *Ring
);
//
// Internal use structure for tracking the submission of a multi-descriptor
// request.
//
typedef struct {
UINT16 HeadDescIdx;
UINT16 NextDescIdx;
} DESC_INDICES;
/**
Turn off interrupt notifications from the host, and prepare for appending
multiple descriptors to the virtio ring.
The calling driver must be in VSTAT_DRIVER_OK state.
@param[in,out] Ring The virtio ring we intend to append descriptors to.
@param[out] Indices The DESC_INDICES structure to initialize.
**/
VOID
EFIAPI
VirtioPrepare (
IN OUT VRING *Ring,
OUT DESC_INDICES *Indices
);
/**
Append a contiguous buffer for transmission / reception via the virtio ring.
This function implements the following section from virtio-0.9.5:
- 2.4.1.1 Placing Buffers into the Descriptor Table
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.
The caller is responsible for initializing *Indices with VirtioPrepare()
first.
@param[in,out] Ring The virtio ring to append the buffer to,
as a descriptor.
@param[in] BufferDeviceAddress (Bus master device) 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,out] Indices Indices->HeadDescIdx is not accessed.
On input, Indices->NextDescIdx identifies
the next descriptor to carry the buffer.
On output, Indices->NextDescIdx is
incremented by one, modulo 2^16.
**/
VOID
EFIAPI
VirtioAppendDesc (
IN OUT VRING *Ring,
IN UINT64 BufferDeviceAddress,
IN UINT32 BufferSize,
IN UINT16 Flags,
IN OUT DESC_INDICES *Indices
);
/**
Notify the host about the descriptor chain just built, and wait until the
host processes it.
@param[in] VirtIo The target virtio device to notify.
@param[in] VirtQueueId Identifies the queue for the target device.
@param[in,out] Ring The virtio ring with descriptors to submit.
@param[in] Indices Indices->NextDescIdx is not accessed.
Indices->HeadDescIdx identifies the head descriptor
of the descriptor chain.
@param[out] UsedLen On success, the total number of bytes, consecutively
across the buffers linked by the descriptor chain,
that the host wrote. May be NULL if the caller
doesn't care, or can compute the same information
from device-specific request structures linked by the
descriptor chain.
@return Error code from VirtIo->SetQueueNotify() if it fails.
@retval EFI_SUCCESS Otherwise, the host processed all descriptors.
**/
EFI_STATUS
EFIAPI
VirtioFlush (
IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
IN UINT16 VirtQueueId,
IN OUT VRING *Ring,
IN DESC_INDICES *Indices,
OUT UINT32 *UsedLen OPTIONAL
);
/**
Report the feature bits to the VirtIo 1.0 device that the VirtIo 1.0 driver
understands.
In VirtIo 1.0, a device can reject a self-inconsistent feature bitmap through
the new VSTAT_FEATURES_OK status bit. (For example if the driver requests a
higher level feature but clears a prerequisite feature.) This function is a
small wrapper around VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures() that also
verifies if the VirtIo 1.0 device accepts the feature bitmap.
@param[in] VirtIo Report feature bits to this device.
@param[in] Features The set of feature bits that the driver wishes
to report. The caller is responsible to perform
any masking before calling this function; the
value is directly written with
VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures().
@param[in,out] DeviceStatus On input, the status byte most recently written
to the device's status register. On output (even
on error), DeviceStatus will be updated so that
it is suitable for further status bit
manipulation and writing to the device's status
register.
@retval EFI_SUCCESS The device accepted the configuration in Features.
@return EFI_UNSUPPORTED The device rejected the configuration in Features.
@retval EFI_UNSUPPORTED VirtIo->Revision is smaller than 1.0.0.
@return Error codes from the SetGuestFeatures(),
SetDeviceStatus(), GetDeviceStatus() member
functions.
**/
EFI_STATUS
EFIAPI
Virtio10WriteFeatures (
IN VIRTIO_DEVICE_PROTOCOL *VirtIo,
IN UINT64 Features,
IN OUT UINT8 *DeviceStatus
);
/**
Provides the virtio device address required to access system memory from a
DMA bus master.
The interface follows the same usage pattern as defined in UEFI spec 2.6
(Section 13.2 PCI Root Bridge I/O Protocol)
The VirtioMapAllBytesInSharedBuffer() is similar to VIRTIO_MAP_SHARED
with exception that NumberOfBytes is IN-only parameter. The function
maps all the bytes specified in NumberOfBytes param in one consecutive
range.
@param[in] VirtIo The virtio device for which the mapping is
requested.
@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] NumberOfBytes Number of bytes to map.
@param[out] DeviceAddress The resulting shared map address for the
bus master to access the hosts HostAddress.
@param[out] Mapping A resulting token to pass to
VIRTIO_UNMAP_SHARED.
@retval EFI_SUCCESS The NumberOfBytes is successfully mapped.
@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. This includes the case
when NumberOfBytes bytes cannot be mapped
in one consecutive range.
@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_
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