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Diffstat (limited to 'roms/edk2/OvmfPkg/Include/Library/VirtioLib.h')
| -rw-r--r-- | roms/edk2/OvmfPkg/Include/Library/VirtioLib.h | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/roms/edk2/OvmfPkg/Include/Library/VirtioLib.h b/roms/edk2/OvmfPkg/Include/Library/VirtioLib.h new file mode 100644 index 000000000..e714ec7ae --- /dev/null +++ b/roms/edk2/OvmfPkg/Include/Library/VirtioLib.h @@ -0,0 +1,316 @@ +/** @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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