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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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C
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322/* SPDX-License-Identifier: GPL-2.0-or-later *//* * Linux host-side vring helpers; for when the kernel needs to access * someone else's vring. * * Copyright IBM Corporation, 2013. * Parts taken from drivers/vhost/vhost.c Copyright 2009 Red Hat, Inc. * * Written by: Rusty Russell <rusty@rustcorp.com.au> */#ifndef _LINUX_VRINGH_H#define _LINUX_VRINGH_H#include <uapi/linux/virtio_ring.h>#include <linux/virtio_byteorder.h>#include <linux/uio.h>#include <linux/slab.h>#include <linux/spinlock.h>#if IS_REACHABLE(CONFIG_VHOST_IOTLB)#include <linux/dma-direction.h>#include <linux/vhost_iotlb.h>#endif#include <asm/barrier.h>
/* virtio_ring with information needed for host access. */struct vringh { /* Everything is little endian */ bool little_endian;
/* Guest publishes used event idx (note: we always do). */ bool event_indices;
/* Can we get away with weak barriers? */ bool weak_barriers;
/* Use user's VA */ bool use_va;
/* Last available index we saw (ie. where we're up to). */ u16 last_avail_idx;
/* Last index we used. */ u16 last_used_idx;
/* How many descriptors we've completed since last need_notify(). */ u32 completed;
/* The vring (note: it may contain user pointers!) */ struct vring vring;
/* IOTLB for this vring */ struct vhost_iotlb *iotlb;
/* spinlock to synchronize IOTLB accesses */ spinlock_t *iotlb_lock;
/* The function to call to notify the guest about added buffers */ void (*notify)(struct vringh *);};
struct virtio_device;typedef void vrh_callback_t(struct virtio_device *, struct vringh *);
/** * struct vringh_config_ops - ops for creating a host vring from a virtio driver * @find_vrhs: find the host vrings and instantiate them * vdev: the virtio_device * nhvrs: the number of host vrings to find * hvrs: on success, includes new host vrings * callbacks: array of driver callbacks, for each host vring * include a NULL entry for vqs that do not need a callback * Returns 0 on success or error status * @del_vrhs: free the host vrings found by find_vrhs(). */struct vringh_config_ops { int (*find_vrhs)(struct virtio_device *vdev, unsigned nhvrs, struct vringh *vrhs[], vrh_callback_t *callbacks[]); void (*del_vrhs)(struct virtio_device *vdev);};
/* The memory the vring can access, and what offset to apply. */struct vringh_range { u64 start, end_incl; u64 offset;};
/** * struct vringh_iov - iovec mangler. * @iov: array of iovecs to operate on * @consumed: number of bytes consumed within iov[i] * @i: index of current iovec * @used: number of iovecs present in @iov * @max_num: maximum number of iovecs. * corresponds to allocated memory of @iov * * Mangles iovec in place, and restores it. * Remaining data is iov + i, of used - i elements. */struct vringh_iov { struct iovec *iov; size_t consumed; /* Within iov[i] */ unsigned i, used, max_num;};
/** * struct vringh_kiov - kvec mangler. * @iov: array of iovecs to operate on * @consumed: number of bytes consumed within iov[i] * @i: index of current iovec * @used: number of iovecs present in @iov * @max_num: maximum number of iovecs. * corresponds to allocated memory of @iov * * Mangles kvec in place, and restores it. * Remaining data is iov + i, of used - i elements. */struct vringh_kiov { struct kvec *iov; size_t consumed; /* Within iov[i] */ unsigned i, used, max_num;};
/* Flag on max_num to indicate we're kmalloced. */#define VRINGH_IOV_ALLOCATED 0x8000000
/* Helpers for userspace vrings. */int vringh_init_user(struct vringh *vrh, u64 features, unsigned int num, bool weak_barriers, vring_desc_t __user *desc, vring_avail_t __user *avail, vring_used_t __user *used);
static inline void vringh_iov_init(struct vringh_iov *iov, struct iovec *iovec, unsigned num){ iov->used = iov->i = 0; iov->consumed = 0; iov->max_num = num; iov->iov = iovec;}
static inline void vringh_iov_reset(struct vringh_iov *iov){ iov->iov[iov->i].iov_len += iov->consumed; iov->iov[iov->i].iov_base -= iov->consumed; iov->consumed = 0; iov->i = 0;}
static inline void vringh_iov_cleanup(struct vringh_iov *iov){ if (iov->max_num & VRINGH_IOV_ALLOCATED) kfree(iov->iov); iov->max_num = iov->used = iov->i = iov->consumed = 0; iov->iov = NULL;}
/* Convert a descriptor into iovecs. */int vringh_getdesc_user(struct vringh *vrh, struct vringh_iov *riov, struct vringh_iov *wiov, bool (*getrange)(struct vringh *vrh, u64 addr, struct vringh_range *r), u16 *head);
/* Copy bytes from readable vsg, consuming it (and incrementing wiov->i). */ssize_t vringh_iov_pull_user(struct vringh_iov *riov, void *dst, size_t len);
/* Copy bytes into writable vsg, consuming it (and incrementing wiov->i). */ssize_t vringh_iov_push_user(struct vringh_iov *wiov, const void *src, size_t len);
/* Mark a descriptor as used. */int vringh_complete_user(struct vringh *vrh, u16 head, u32 len);int vringh_complete_multi_user(struct vringh *vrh, const struct vring_used_elem used[], unsigned num_used);
/* Do we need to fire the eventfd to notify the other side? */int vringh_need_notify_user(struct vringh *vrh);
bool vringh_notify_enable_user(struct vringh *vrh);void vringh_notify_disable_user(struct vringh *vrh);
/* Helpers for kernelspace vrings. */int vringh_init_kern(struct vringh *vrh, u64 features, unsigned int num, bool weak_barriers, struct vring_desc *desc, struct vring_avail *avail, struct vring_used *used);
static inline void vringh_kiov_init(struct vringh_kiov *kiov, struct kvec *kvec, unsigned num){ kiov->used = kiov->i = 0; kiov->consumed = 0; kiov->max_num = num; kiov->iov = kvec;}
static inline void vringh_kiov_reset(struct vringh_kiov *kiov){ kiov->iov[kiov->i].iov_len += kiov->consumed; kiov->iov[kiov->i].iov_base -= kiov->consumed; kiov->consumed = 0; kiov->i = 0;}
static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov){ if (kiov->max_num & VRINGH_IOV_ALLOCATED) kfree(kiov->iov); kiov->max_num = kiov->used = kiov->i = kiov->consumed = 0; kiov->iov = NULL;}
static inline size_t vringh_kiov_length(struct vringh_kiov *kiov){ size_t len = 0; int i;
for (i = kiov->i; i < kiov->used; i++) len += kiov->iov[i].iov_len;
return len;}
void vringh_kiov_advance(struct vringh_kiov *kiov, size_t len);
int vringh_getdesc_kern(struct vringh *vrh, struct vringh_kiov *riov, struct vringh_kiov *wiov, u16 *head, gfp_t gfp);
int vringh_complete_kern(struct vringh *vrh, u16 head, u32 len);
bool vringh_notify_enable_kern(struct vringh *vrh);void vringh_notify_disable_kern(struct vringh *vrh);
int vringh_need_notify_kern(struct vringh *vrh);
/* Notify the guest about buffers added to the used ring */static inline void vringh_notify(struct vringh *vrh){ if (vrh->notify) vrh->notify(vrh);}
static inline bool vringh_is_little_endian(const struct vringh *vrh){ return vrh->little_endian || virtio_legacy_is_little_endian();}
static inline u16 vringh16_to_cpu(const struct vringh *vrh, __virtio16 val){ return __virtio16_to_cpu(vringh_is_little_endian(vrh), val);}
static inline __virtio16 cpu_to_vringh16(const struct vringh *vrh, u16 val){ return __cpu_to_virtio16(vringh_is_little_endian(vrh), val);}
static inline u32 vringh32_to_cpu(const struct vringh *vrh, __virtio32 val){ return __virtio32_to_cpu(vringh_is_little_endian(vrh), val);}
static inline __virtio32 cpu_to_vringh32(const struct vringh *vrh, u32 val){ return __cpu_to_virtio32(vringh_is_little_endian(vrh), val);}
static inline u64 vringh64_to_cpu(const struct vringh *vrh, __virtio64 val){ return __virtio64_to_cpu(vringh_is_little_endian(vrh), val);}
static inline __virtio64 cpu_to_vringh64(const struct vringh *vrh, u64 val){ return __cpu_to_virtio64(vringh_is_little_endian(vrh), val);}
#if IS_REACHABLE(CONFIG_VHOST_IOTLB)
void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb, spinlock_t *iotlb_lock);
int vringh_init_iotlb(struct vringh *vrh, u64 features, unsigned int num, bool weak_barriers, struct vring_desc *desc, struct vring_avail *avail, struct vring_used *used);
int vringh_init_iotlb_va(struct vringh *vrh, u64 features, unsigned int num, bool weak_barriers, struct vring_desc *desc, struct vring_avail *avail, struct vring_used *used);
int vringh_getdesc_iotlb(struct vringh *vrh, struct vringh_kiov *riov, struct vringh_kiov *wiov, u16 *head, gfp_t gfp);
ssize_t vringh_iov_pull_iotlb(struct vringh *vrh, struct vringh_kiov *riov, void *dst, size_t len);ssize_t vringh_iov_push_iotlb(struct vringh *vrh, struct vringh_kiov *wiov, const void *src, size_t len);
int vringh_complete_iotlb(struct vringh *vrh, u16 head, u32 len);
int vringh_need_notify_iotlb(struct vringh *vrh);
#endif /* CONFIG_VHOST_IOTLB */
#endif /* _LINUX_VRINGH_H */