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/*
* Copyright (c) 2019 Nutanix Inc. All rights reserved.
*
* Authors: Thanos Makatos <thanos@nutanix.com>
* Swapnil Ingle <swapnil.ingle@nutanix.com>
* Felipe Franciosi <felipe@nutanix.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Nutanix nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
*/
/*
* Defines the libvfio-user server-side API. The protocol definitions can be
* found in vfio-user.h.
*/
#ifndef LIB_VFIO_USER_H
#define LIB_VFIO_USER_H
#include <stdint.h>
#include <sys/uio.h>
#include <unistd.h>
#include <syslog.h>
#include "pci.h"
#include "pci_caps/pm.h"
#include "pci_caps/px.h"
#include "pci_caps/msi.h"
#include "pci_caps/msix.h"
#include "vfio-user.h"
#ifdef __cplusplus
extern "C" {
#endif
#define LIB_VFIO_USER_MAJOR 0
#define LIB_VFIO_USER_MINOR 1
#define VFU_DMA_REGIONS 0x10
// FIXME: too common a name?
typedef uint64_t dma_addr_t;
typedef struct {
dma_addr_t dma_addr;
int region; /* TODO replace region and length with struct iovec */
int length;
uint64_t offset;
bool mappable;
} dma_sg_t;
typedef struct vfu_ctx vfu_ctx_t;
/*
* Attaching to the transport is non-blocking.
* The caller must then manually call vfu_attach_ctx(),
* which is non-blocking, as many times as necessary.
*/
#define LIBVFIO_USER_FLAG_ATTACH_NB (1 << 0)
typedef enum {
VFU_TRANS_SOCK,
VFU_TRANS_MAX
} vfu_trans_t;
typedef enum {
VFU_DEV_TYPE_PCI
} vfu_dev_type_t;
/**
* Creates libvfio-user context. By default one ERR and one REQ IRQs are
* initialized, this can be overridden with vfu_setup_device_nr_irqs.
*
* @trans: transport type
* @path: path to socket file.
* @flags: context flags
* @pvt: private data
* @dev_type: device type
*
* @returns the vfu_ctx to be used or NULL on error. Sets errno.
*/
vfu_ctx_t *
vfu_create_ctx(vfu_trans_t trans, const char *path,
int flags, void *pvt, vfu_dev_type_t dev_type);
/*
* Finalizes the device making it ready for vfu_attach_ctx(). This function is
* mandatory to be called before vfu_attach_ctx().
* @vfu_ctx: the libvfio-user context
*
* @returns: 0 on success, -1 on error. Sets errno.
*/
int
vfu_realize_ctx(vfu_ctx_t *vfu_ctx);
/*
* Attempts to attach to the transport. Attach is mandatory before
* vfu_run_ctx() and is non blocking if context is created
* with LIBVFIO_USER_FLAG_ATTACH_NB flag.
* Returns client's file descriptor on success and -1 on error. If errno is
* set to EAGAIN or EWOULDBLOCK then the transport is not ready to attach to and
* the operation must be retried.
*
* @vfu_ctx: the libvfio-user context
*/
int
vfu_attach_ctx(vfu_ctx_t *vfu_ctx);
/**
* Polls the vfu_ctx and processes the command recieved from client.
* - Blocking vfu_ctx:
* Blocks until new request is received from client and continues processing
* the requests. Exits only in case of error or if the client disconnects.
* - Non-blocking vfu_ctx(LIBVFIO_USER_FLAG_ATTACH_NB):
* Processes one request from client if it's available, otherwise it
* immediatelly returns and the caller is responsible for periodically
* calling again.
*
* @vfu_ctx: The libvfio-user context to poll
*
* @returns 0 on success, -errno on failure.
*/
int
vfu_run_ctx(vfu_ctx_t *vfu_ctx);
/**
* Destroys libvfio-user context.
*
* @vfu_ctx: the libvfio-user context to destroy
*/
void
vfu_destroy_ctx(vfu_ctx_t *vfu_ctx);
/**
* Return the private pointer given to vfu_create_ctx().
*/
void *
vfu_get_private(vfu_ctx_t *vfu_ctx);
/**
* Callback function signature for log function
* @vfu_ctx: the libvfio-user context
* @level: log level as defined in syslog(3)
* @vfu_log_fn_t: typedef for log function.
* @msg: message
*/
typedef void (vfu_log_fn_t)(vfu_ctx_t *vfu_ctx, int level, const char *msg);
/**
* Log to the logging function configured for this context.
*/
void
vfu_log(vfu_ctx_t *vfu_ctx, int level, const char *fmt, ...);
/**
* Setup logging information.
* @vfu_ctx: the libvfio-user context
* @log: logging function
* @level: logging level as defined in syslog(3)
*/
int
vfu_setup_log(vfu_ctx_t *vfu_ctx, vfu_log_fn_t *log, int level);
/**
* Creates a mapping of a device region into the caller's virtual memory. It
* must be called by vfu_map_region_cb_t.
*
* @vfu_ctx: the context to create mapping from
* @offset: offset of the region being mapped
* @length: size of the region being mapped
*
* @returns a pointer to the requested memory or MAP_FAILED on error. Sets errno.
*/
void *
vfu_mmap(vfu_ctx_t * vfu_ctx, off_t offset, size_t length);
/**
* Prototype for region access callback. When a region is accessed, libvfio-user
* calls the previously registered callback with the following arguments:
*
* @vfu_ctx: the libvfio-user context
* @buf: buffer containing the data to be written or data to be read into
* @count: number of bytes being read or written
* @offset: byte offset within the region
* @is_write: whether or not this is a write
*
* @returns the number of bytes read or written, or a negative integer on error
*/
typedef ssize_t (vfu_region_access_cb_t)(vfu_ctx_t *vfu_ctx, char *buf,
size_t count, loff_t offset,
bool is_write);
#define VFU_REGION_FLAG_READ (1 << 0)
#define VFU_REGION_FLAG_WRITE (1 << 1)
#define VFU_REGION_FLAG_MMAP (1 << 2) // TODO: how this relates to IO bar?
#define VFU_REGION_FLAG_RW (VFU_REGION_FLAG_READ | VFU_REGION_FLAG_WRITE)
#define VFU_REGION_FLAG_MEM (1 << 3) // if unset, bar is IO
/**
* Set up a region.
*
* If this is the PCI configuration space, the @size argument is ignored. The
* size of the region is determined by the PCI type (set when the libvfio-user
* context is created). Accesses to the PCI configuration space header and the
* PCI capabilities are handled internally; the user supplied callback is not
* called.
*
* @vfu_ctx: the libvfio-user context
* @region_idx: region index
* @size: size of the region
* @region_access: callback function to access region. If the region is memory
* mappable and the client accesses the region or part of sparse area, then
* the callback is not called.
* @flags: region flags (VFU_REGION_FLAG_)
* @mmap_areas: array of memory mappable areas. This array provides to the
* server greater control of which specific areas should be memory mapped by
* the client. Each element in the @mmap_areas array describes one such area.
* Ignored if @nr_mmap_areas is 0 or if the region is not memory mappable.
* @nr_mmap_areas: number of sparse areas in @mmap_areas. Must be 0 if the
* region is not memory mappable.
* @fd: file descriptor of the file backing the region if it's a mappable
* region. It is the server's responsibility to create a file suitable for
* memory mapping by the client. Ignored if the region is not memory mappable.
*
* A note on memory-mappable regions: the client can memory map any part of the
* file descriptor, even if not supposed to do so acocrding to @mmap_areas.
* There is no way in Linux to avoid this.
*
* TODO maybe we should introduce per-sparse region file descriptors so that
* the client cannot possibly memory map areas it's not supposed to. Even if
* the client needs to have region under the same backing file, it is possible
* to create linear device-mapper targets, one for each area, and provide file
* descriptors of these DM targets. This is something we can document and
* demonstrate in a sample.
*
* @returns 0 on success, -1 on error, Sets errno.
*/
int
vfu_setup_region(vfu_ctx_t *vfu_ctx, int region_idx, size_t size,
vfu_region_access_cb_t *region_access, int flags,
struct iovec *mmap_areas, uint32_t nr_mmap_areas,
int fd);
/*
* Callback function that is called when the guest resets the device.
*/
typedef int (vfu_reset_cb_t)(vfu_ctx_t *vfu_ctx);
/**
* Setup device reset callback.
* @vfu_ctx: the libvfio-user context
* @reset: device reset callback (optional)
*/
int
vfu_setup_device_reset_cb(vfu_ctx_t *vfu_ctx, vfu_reset_cb_t *reset);
/*
* Function that is called when the guest maps a DMA region. Optional.
*
* @vfu_ctx: the libvfio-user context
* @iova: iova address
* @len: length
*/
typedef void (vfu_map_dma_cb_t)(vfu_ctx_t *vfu_ctx,
uint64_t iova, uint64_t len);
/*
* Function that is called when the guest unmaps a DMA region. The device
* must release all references to that region before the callback returns.
* This is required if you want to be able to access guest memory.
*
* @vfu_ctx: the libvfio-user context
* @iova: iova address
* @len: length
*/
typedef int (vfu_unmap_dma_cb_t)(vfu_ctx_t *vfu_ctx,
uint64_t iova, uint64_t len);
/**
* Setup device DMA map/unmap callbacks. This will also enable bookkeeping of
* DMA regions received from client, otherwise they will be just acknowledged.
*
* @vfu_ctx: the libvfio-user context
* @map_dma: DMA region map callback (optional)
* @unmap_dma: DMA region unmap callback (optional)
*/
int
vfu_setup_device_dma_cb(vfu_ctx_t *vfu_ctx, vfu_map_dma_cb_t *map_dma,
vfu_unmap_dma_cb_t *unmap_dma);
enum vfu_dev_irq_type {
VFU_DEV_INTX_IRQ,
VFU_DEV_MSI_IRQ,
VFU_DEV_MSIX_IRQ,
VFU_DEV_ERR_IRQ,
VFU_DEV_REQ_IRQ,
VFU_DEV_NUM_IRQS
};
/**
* Setup device IRQ counts.
* @vfu_ctx: the libvfio-user context
* @type: IRQ type (VFU_DEV_INTX_IRQ ... VFU_DEV_REQ_IRQ)
* @count: number of irqs
*/
int
vfu_setup_device_nr_irqs(vfu_ctx_t *vfu_ctx, enum vfu_dev_irq_type type,
uint32_t count);
/*
* FIXME the names of migration callback functions are probably far too long,
* but for now it helps with the implementation.
*/
/**
* Migration callback function.
* @vfu_ctx: the libvfio-user context
*/
typedef int (vfu_migration_callback_t)(vfu_ctx_t *vfu_ctx);
typedef enum {
VFU_MIGR_STATE_STOP,
VFU_MIGR_STATE_RUNNING,
VFU_MIGR_STATE_STOP_AND_COPY,
VFU_MIGR_STATE_PRE_COPY,
VFU_MIGR_STATE_RESUME
} vfu_migr_state_t;
typedef struct {
/* migration state transition callback */
/* TODO rename to vfu_migration_state_transition_callback */
/* FIXME maybe we should create a single callback and pass the state? */
int (*transition)(vfu_ctx_t *vfu_ctx, vfu_migr_state_t state);
/* Callbacks for saving device state */
/*
* Function that is called to retrieve pending migration data. If migration
* data were previously made available (function prepare_data has been
* called) then calling this function signifies that they have been read
* (e.g. migration data can be discarded). If the function returns 0 then
* migration has finished and this function won't be called again.
*/
__u64 (*get_pending_bytes)(vfu_ctx_t *vfu_ctx);
/*
* Function that is called to instruct the device to prepare migration data.
* The function must return only after migration data are available at the
* specified offset.
*/
int (*prepare_data)(vfu_ctx_t *vfu_ctx, __u64 *offset, __u64 *size);
/*
* Function that is called to read migration data. offset and size can
* be any subrange on the offset and size previously returned by
* prepare_data. The function must return the amount of data read. This
* function can be called even if the migration data can be memory mapped.
*
* Does this mean that reading data_offset/data_size updates the values?
*/
size_t (*read_data)(vfu_ctx_t *vfu_ctx, void *buf,
__u64 count, __u64 offset);
/* Callbacks for restoring device state */
/*
* Function that is called when client has written some previously stored
* device state.
*/
int (*data_written)(vfu_ctx_t *vfu_ctx,
__u64 count, __u64 offset);
/* Fuction that is called for writing previously stored device state. */
size_t (*write_data)(vfu_ctx_t *vfu_ctx, void *buf,
__u64 count, __u64 offset);
} vfu_migration_callbacks_t;
typedef struct {
size_t size;
vfu_migration_callbacks_t callbacks;
struct iovec *mmap_areas;
uint32_t nr_mmap_areas;
} vfu_migration_t;
//TODO: Re-visit once migration support is done.
/**
* Enable support for device migration.
* @vfu_ctx: the libvfio-user context
* @migration: information required to migrate device
*/
int
vfu_setup_device_migration(vfu_ctx_t *vfu_ctx, vfu_migration_t *migration);
/**
* Triggers an interrupt.
*
* libvfio-user takes care of using the correct IRQ type (IRQ index: INTx or
* MSI/X), the caller only needs to specify the sub-index.
*
* @vfu_ctx: the libvfio-user context to trigger interrupt
* @subindex: vector subindex to trigger interrupt on
*
* @returns 0 on success, or -1 on failure. Sets errno.
*/
int
vfu_irq_trigger(vfu_ctx_t *vfu_ctx, uint32_t subindex);
/**
* Sends message to client to trigger an interrupt.
*
* libvfio-user takes care of using the IRQ type (INTx, MSI/X), the caller only
* needs to specify the sub-index.
* This api can be used to trigger interrupt by sending message to client.
*
* @vfu_ctx: the libvfio-user context to trigger interrupt
* @subindex: vector subindex to trigger interrupt on
*
* @returns 0 on success, or -1 on failure. Sets errno.
*/
int
vfu_irq_message(vfu_ctx_t *vfu_ctx, uint32_t subindex);
/**
* Takes a guest physical address and returns a list of scatter/gather entries
* than can be individually mapped in the program's virtual memory. A single
* linear guest physical address span may need to be split into multiple
* scatter/gather regions due to limitations of how memory can be mapped.
* Field unmap_dma must have been provided at context creation time in order
* to use this function.
*
* @vfu_ctx: the libvfio-user context
* @dma_addr: the guest physical address
* @len: size of memory to be mapped
* @sg: array that receives the scatter/gather entries to be mapped
* @max_sg: maximum number of elements in above array
* @prot: protection as define in <sys/mman.h>
*
* @returns the number of scatter/gather entries created on success, and on
* failure:
* -1: if the GPA address span is invalid, or
* (-x - 1): if @max_sg is too small, where x is the number of scatter/gather
* entries necessary to complete this request.
*/
int
vfu_addr_to_sg(vfu_ctx_t *vfu_ctx, dma_addr_t dma_addr, uint32_t len,
dma_sg_t *sg, int max_sg, int prot);
/**
* Maps a list scatter/gather entries from the guest's physical address space
* to the program's virtual memory. It is the caller's responsibility to remove
* the mappings by calling vfu_unmap_sg.
* Field unmap_dma must have been provided at context creation time in order
* to use this function.
*
* @vfu_ctx: the libvfio-user context
* @sg: array of scatter/gather entries returned by vfu_addr_to_sg
* @iov: array of iovec structures (defined in <sys/uio.h>) to receive each
* mapping
* @cnt: number of scatter/gather entries to map
*
* @returns 0 on success, -1 on failure
*/
int
vfu_map_sg(vfu_ctx_t *vfu_ctx, const dma_sg_t *sg,
struct iovec *iov, int cnt);
/**
* Unmaps a list scatter/gather entries (previously mapped by vfu_map_sg) from
* the program's virtual memory.
* Field unmap_dma must have been provided at context creation time in order
* to use this function.
*
* @vfu_ctx: the libvfio-user context
* @sg: array of scatter/gather entries to unmap
* @iov: array of iovec structures for each scatter/gather entry
* @cnt: number of scatter/gather entries to unmap
*/
void
vfu_unmap_sg(vfu_ctx_t *vfu_ctx, const dma_sg_t *sg,
struct iovec *iov, int cnt);
//FIXME: Remove if we dont need this.
/**
* Returns the PCI region given the position and size of an address span in the
* PCI configuration space.
*
* @pos: offset of the address span
* @count: size of the address span
* @off: output parameter that receives the relative offset within the region.
*
* Returns the PCI region (VFU_PCI_DEV_XXX_REGION_IDX), or -errno on error.
*/
int
vfu_get_region(loff_t pos, size_t count, loff_t *off);
/**
* Read from the dma region exposed by the client.
*
* @vfu_ctx: the libvfio-user context
* @sg: a DMA segment obtained from dma_addr_to_sg
* @data: data buffer to read into
*/
int
vfu_dma_read(vfu_ctx_t *vfu_ctx, dma_sg_t *sg, void *data);
/**
* Write to the dma region exposed by the client.
*
* @vfu_ctx: the libvfio-user context
* @sg: a DMA segment obtained from dma_addr_to_sg
* @data: data buffer to write
*/
int
vfu_dma_write(vfu_ctx_t *vfu_ctx, dma_sg_t *sg, void *data);
/*
* Supported PCI regions.
*
* FIXME: update with CFG behaviour etc.
*/
enum {
VFU_PCI_DEV_BAR0_REGION_IDX,
VFU_PCI_DEV_BAR1_REGION_IDX,
VFU_PCI_DEV_BAR2_REGION_IDX,
VFU_PCI_DEV_BAR3_REGION_IDX,
VFU_PCI_DEV_BAR4_REGION_IDX,
VFU_PCI_DEV_BAR5_REGION_IDX,
VFU_PCI_DEV_ROM_REGION_IDX,
VFU_PCI_DEV_CFG_REGION_IDX,
VFU_PCI_DEV_VGA_REGION_IDX,
VFU_PCI_DEV_NUM_REGIONS,
};
typedef enum {
VFU_PCI_TYPE_CONVENTIONAL,
VFU_PCI_TYPE_PCI_X_1,
VFU_PCI_TYPE_PCI_X_2,
VFU_PCI_TYPE_EXPRESS
} vfu_pci_type_t;
/**
* Setup PCI configuration space header data. This function must be called only
* once per libvfio-user context.
*
* @vfu_ctx: the libvfio-user context
* @id: Device and vendor ID
* @ss: Subsystem vendor and device ID
* @cc: Class code
* @pci_type: PCI type (convention PCI, PCI-X mode 1, PCI-X mode2, PCI-Express)
* @revision: PCI/PCI-X/PCIe revision
*
* @returns 0 on success, -1 on failure and sets errno.
* TODO: Check other PCI header registers suitable to be filled by device.
* Or should we pass whole vfu_pci_hdr_t to be filled by user.
*/
int
vfu_pci_setup_config_hdr(vfu_ctx_t *vfu_ctx, vfu_pci_hdr_id_t id,
vfu_pci_hdr_ss_t ss, vfu_pci_hdr_cc_t cc,
vfu_pci_type_t pci_type,
int revision __attribute__((unused)));
/*
* Returns a pointer to the PCI configuration space.
*
* PCI config space consists of an initial 64-byte vfu_pci_hdr_t, plus
* additional space, either containing capabilities, or device-specific
* configuration. Standard config space is 256 bytes; extended config space is
* 4096 bytes.
*/
vfu_pci_config_space_t *
vfu_pci_get_config_space(vfu_ctx_t *vfu_ctx);
/* FIXME does it have to be packed as well? */
typedef union {
struct msicap msi;
struct msixcap msix;
struct pmcap pm;
struct pxcap px;
struct vsc vsc;
} vfu_cap_t;
//TODO: Support variable size capabilities.
/**
* Setup PCI capabilities.
*
* @vfu_ctx: the libvfio-user context
* @caps: array of (vfu_cap_t *)
* @nr_caps: number of elements in @caps
*/
int
vfu_pci_setup_caps(vfu_ctx_t *vfu_ctx, vfu_cap_t **caps, int nr_caps);
/* FIXME this function is broken as the can be multiples capabilities with the
* same ID, e.g. the vendor-specific capability.
* @vfu_ctx: the libvfio-user context
* @id: capability id
*/
uint8_t *
vfu_ctx_get_cap(vfu_ctx_t *vfu_ctx, uint8_t id);
#ifdef __cplusplus
}
#endif
#endif /* LIB_VFIO_USER_H */
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