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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 "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
// FIXME: too common a name?
typedef uint64_t dma_addr_t;
typedef struct {
dma_addr_t dma_addr;
int region;
int length;
uint64_t offset;
} dma_sg_t;
typedef struct vfu_ctx vfu_ctx_t;
struct vfu_mmap_area {
uint64_t start;
uint64_t size;
};
struct vfu_sparse_mmap_areas {
int nr_mmap_areas;
struct vfu_mmap_area areas[];
};
/**
* Prototype for memory access callback. The program MUST first map device
* memory in its own virtual address space using vfu_mmap, do any additional work
* required, and finally return that memory. When a region is memory mapped,
* libvfio-user calls the previously registered callback with the following
* arguments:
*
* @pvt: private pointer
* @off: offset of memory area being memory mapped
* @len: length of memory area being memory mapped
*
* @returns the memory address returned by vfu_mmap, or MAP_FAILED on failure
*/
typedef unsigned long (vfu_map_region_cb_t) (void *pvt, unsigned long off,
unsigned long len);
/**
* 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);
/*
* Returns a pointer to the standard part of the PCI configuration space.
*/
vfu_pci_config_space_t *
vfu_pci_get_config_space(vfu_ctx_t *vfu_ctx);
#define VFU_DMA_REGIONS 0x10
typedef enum {
VFU_ERR,
VFU_INF,
VFU_DBG
} vfu_log_lvl_t;
/**
* Callback function signature for log function
* @pvt: private pointer
* @vfu_log_fn_t: typedef for log function.
* @msg: message
*/
typedef void (vfu_log_fn_t) (void *pvt, vfu_log_lvl_t lvl, const char *msg);
/**
* Callback function that gets called when a capability is accessed. The
* callback is not called when the ID and next fields are accessed, these are
* handled by the library.
*
* @pvt: private pointer
* @id: capability ID being accessed
* @buf: pointer to data being read or written
* @count: number of bytes being read or written
* @offset: offset within the capability
* @is_write: whether the capability is read or written
*
* @returns the number of bytes read or written
*/
typedef ssize_t (vfu_cap_access_t) (void *pvt, uint8_t id,
char *buf, size_t count,
loff_t offset, bool is_write);
/* FIXME does it have to be packed as well? */
typedef union {
struct msicap msi;
struct msixcap msix;
struct pmcap pm;
struct pxcap px;
} vfu_cap_t;
typedef enum {
VFU_TRANS_SOCK,
VFU_TRANS_MAX
} vfu_trans_t;
#define VFU_MAX_CAPS (PCI_CFG_SPACE_SIZE - PCI_STD_HEADER_SIZEOF) / PCI_CAP_SIZEOF
/*
* FIXME the names of migration callback functions are probably far too long,
* but for now it helps with the implementation.
*/
/**
* Migration callback function.
* @pvt: private pointer
*/
typedef int (vfu_migration_callback_t)(void *pvt);
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)(void *pvt, 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)(void *pvt);
/*
* 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)(void *pvt, __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)(void *pvt, 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)(void *pvt, __u64 count, __u64 offset);
/* Fuction that is called for writing previously stored device state. */
size_t (*write_data)(void *pvt, void *buf, __u64 count, __u64 offset);
} vfu_migration_callbacks_t;
typedef struct {
size_t size;
vfu_migration_callbacks_t callbacks;
struct vfu_sparse_mmap_areas *mmap_areas;
} vfu_migration_t;
/*
* Attaching to the transport is non-blocking. The library will not attempt
* to attach during context creation time. The caller must then manually
* call vfu_ctx_try_attach(), which is non-blocking, as many times as
* necessary.
*/
#define LIBVFIO_USER_FLAG_ATTACH_NB (1 << 0)
/**
* Creates libvfio-user context.
* @trans: transport type
* @path: path to socket file.
* @flags: context flag
* @pvt: private data
* @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);
/**
* Setup logging information.
* @vfu_ctx: the libvfio-user context
* @log: logging function
* @log_lvl: logging level
*/
int
vfu_setup_log(vfu_ctx_t *vfu_ctx, vfu_log_fn_t *log, vfu_log_lvl_t log_lvl);
//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.
/**
* Setup PCI header data.
* @vfu_ctx: the libvfio-user context
* @id: Device and vendor ID
* @ss: Subsystem vendor and device ID
* @cc: Class code
* @extended: support extended PCI config space
*/
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,
bool extended);
//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);
// Region flags.
#define VFU_REG_FLAG_READ (1 << 0)
#define VFU_REG_FLAG_WRITE (1 << 1)
#define VFU_REG_FLAG_MMAP (1 << 2) // TODO: how this relates to IO bar?
#define VFU_REG_FLAG_RW (VFU_REG_FLAG_READ | VFU_REG_FLAG_WRITE)
#define VFU_REG_FLAG_MEM (1 << 3) // if unset, bar is IO
/**
* Prototype for region access callback. When a region is accessed, libvfio-user
* calls the previously registered callback with the following arguments:
*
* @pvt: private data originally passed by vfu_create_ctx()
* @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) (void *pvt, char *buf, size_t count,
loff_t offset, bool is_write);
/* PCI regions */
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,
};
/**
* Set up a region.
* @vfu_ctx: the libvfio-user context
* @region_idx: region index
* @size: size of the region
* @region_access: callback function to access region
* @flags: region flags
* @mmap_areas: mmap areas info
* @region_map: callback function to map region
*/
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 vfu_sparse_mmap_areas *mmap_areas,
vfu_map_region_cb_t *map);
/*
* Callback function that is called when the guest resets the device.
* @pvt: private pointer
*/
typedef int (vfu_reset_cb_t) (void *pvt);
/*
* Function that is called when the guest maps a DMA region. Optional.
* @pvt: private pointer
* @iova: iova address
* @len: length
*/
typedef void (vfu_map_dma_cb_t) (void *pvt, 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.
* @pvt: private pointer
* @iova: iova address
* @len: length
*/
typedef int (vfu_unmap_dma_cb_t) (void *pvt, uint64_t iova, uint64_t len);
/**
* 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);
/**
* Setup device DMA map/unmap callbacks.
* @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);
//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);
/**
* Destroys libvfio-user context.
*
* @vfu_ctx: the libvfio-user context to destroy
*/
void
vfu_ctx_destroy(vfu_ctx_t *vfu_ctx);
/**
* Once the vfu_ctx is configured vfu_ctx_drive() drives it. This function waits
* for commands coming from the client, and processes them in a loop.
*
* @vfu_ctx: the libvfio-user context to drive
*
* @returns 0 on success, -errno on failure.
*/
int
vfu_ctx_drive(vfu_ctx_t *vfu_ctx);
/**
* Polls, without blocking, an vfu_ctx. This is an alternative to using
* a thread and making a blocking call to vfu_ctx_drive(). Instead, the
* application can periodically poll the context directly from one of
* its own threads.
*
* This is only allowed when LIBVFIO_USER_FLAG_ATTACH_NB is specified during
* creation.
*
* @vfu_ctx: The libvfio-user context to poll
*
* @returns 0 on success, -errno on failure.
*/
int
vfu_ctx_poll(vfu_ctx_t *vfu_ctx);
/**
* 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);
/* Helper functions */
/**
* Converts a guest physical address to a dma_sg_t element which can
* be later passed on to vfu_map_sg to memory map the GPA. It is the caller's
* responsibility to unmap it by calling vfu_unmap_sg.
*
*/
/**
* 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);
/*
* Advanced stuff.
*/
/**
* Returns the non-standard part of the PCI configuration space.
* @vfu_ctx: the libvfio-user context
*/
uint8_t *
vfu_get_pci_non_std_config_space(vfu_ctx_t *vfu_ctx);
/*
* Attempts to attach to the transport. LIBVFIO_USER_FLAG_ATTACH_NB must be set
* when creating the context. Returns 0 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_ctx_try_attach(vfu_ctx_t *vfu_ctx);
/*
* FIXME need to make sure that there can be at most one capability with a given
* ID, otherwise this function will return the first one with this ID.
* @vfu_ctx: the libvfio-user context
* @id: capability id
*/
uint8_t *
vfu_ctx_get_cap(vfu_ctx_t *vfu_ctx, uint8_t id);
void
vfu_log(vfu_ctx_t *vfu_ctx, vfu_log_lvl_t lvl, const char *fmt, ...);
#ifdef __cplusplus
}
#endif
#endif /* LIB_VFIO_USER_H */
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