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-rw-r--r--drivers/vhost/vhost.h343
1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
new file mode 100644
index 0000000000..f60d5f7bef
--- /dev/null
+++ b/drivers/vhost/vhost.h
@@ -0,0 +1,343 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _VHOST_H
+#define _VHOST_H
+
+#include <linux/eventfd.h>
+#include <linux/vhost.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/file.h>
+#include <linux/uio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+#include <linux/atomic.h>
+#include <linux/vhost_iotlb.h>
+#include <linux/irqbypass.h>
+
+struct vhost_work;
+struct vhost_task;
+typedef void (*vhost_work_fn_t)(struct vhost_work *work);
+
+#define VHOST_WORK_QUEUED 1
+struct vhost_work {
+ struct llist_node node;
+ vhost_work_fn_t fn;
+ unsigned long flags;
+};
+
+struct vhost_worker {
+ struct vhost_task *vtsk;
+ /* Used to serialize device wide flushing with worker swapping. */
+ struct mutex mutex;
+ struct llist_head work_list;
+ u64 kcov_handle;
+ u32 id;
+ int attachment_cnt;
+};
+
+/* Poll a file (eventfd or socket) */
+/* Note: there's nothing vhost specific about this structure. */
+struct vhost_poll {
+ poll_table table;
+ wait_queue_head_t *wqh;
+ wait_queue_entry_t wait;
+ struct vhost_work work;
+ __poll_t mask;
+ struct vhost_dev *dev;
+ struct vhost_virtqueue *vq;
+};
+
+void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn,
+ __poll_t mask, struct vhost_dev *dev,
+ struct vhost_virtqueue *vq);
+int vhost_poll_start(struct vhost_poll *poll, struct file *file);
+void vhost_poll_stop(struct vhost_poll *poll);
+void vhost_poll_queue(struct vhost_poll *poll);
+
+void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn);
+void vhost_dev_flush(struct vhost_dev *dev);
+
+struct vhost_log {
+ u64 addr;
+ u64 len;
+};
+
+enum vhost_uaddr_type {
+ VHOST_ADDR_DESC = 0,
+ VHOST_ADDR_AVAIL = 1,
+ VHOST_ADDR_USED = 2,
+ VHOST_NUM_ADDRS = 3,
+};
+
+struct vhost_vring_call {
+ struct eventfd_ctx *ctx;
+ struct irq_bypass_producer producer;
+};
+
+/* The virtqueue structure describes a queue attached to a device. */
+struct vhost_virtqueue {
+ struct vhost_dev *dev;
+ struct vhost_worker __rcu *worker;
+
+ /* The actual ring of buffers. */
+ struct mutex mutex;
+ unsigned int num;
+ vring_desc_t __user *desc;
+ vring_avail_t __user *avail;
+ vring_used_t __user *used;
+ const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS];
+ struct file *kick;
+ struct vhost_vring_call call_ctx;
+ struct eventfd_ctx *error_ctx;
+ struct eventfd_ctx *log_ctx;
+
+ struct vhost_poll poll;
+
+ /* The routine to call when the Guest pings us, or timeout. */
+ vhost_work_fn_t handle_kick;
+
+ /* Last available index we saw.
+ * Values are limited to 0x7fff, and the high bit is used as
+ * a wrap counter when using VIRTIO_F_RING_PACKED. */
+ u16 last_avail_idx;
+
+ /* Caches available index value from user. */
+ u16 avail_idx;
+
+ /* Last index we used.
+ * Values are limited to 0x7fff, and the high bit is used as
+ * a wrap counter when using VIRTIO_F_RING_PACKED. */
+ u16 last_used_idx;
+
+ /* Used flags */
+ u16 used_flags;
+
+ /* Last used index value we have signalled on */
+ u16 signalled_used;
+
+ /* Last used index value we have signalled on */
+ bool signalled_used_valid;
+
+ /* Log writes to used structure. */
+ bool log_used;
+ u64 log_addr;
+
+ struct iovec iov[UIO_MAXIOV];
+ struct iovec iotlb_iov[64];
+ struct iovec *indirect;
+ struct vring_used_elem *heads;
+ /* Protected by virtqueue mutex. */
+ struct vhost_iotlb *umem;
+ struct vhost_iotlb *iotlb;
+ void *private_data;
+ u64 acked_features;
+ u64 acked_backend_features;
+ /* Log write descriptors */
+ void __user *log_base;
+ struct vhost_log *log;
+ struct iovec log_iov[64];
+
+ /* Ring endianness. Defaults to legacy native endianness.
+ * Set to true when starting a modern virtio device. */
+ bool is_le;
+#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
+ /* Ring endianness requested by userspace for cross-endian support. */
+ bool user_be;
+#endif
+ u32 busyloop_timeout;
+};
+
+struct vhost_msg_node {
+ union {
+ struct vhost_msg msg;
+ struct vhost_msg_v2 msg_v2;
+ };
+ struct vhost_virtqueue *vq;
+ struct list_head node;
+};
+
+struct vhost_dev {
+ struct mm_struct *mm;
+ struct mutex mutex;
+ struct vhost_virtqueue **vqs;
+ int nvqs;
+ struct eventfd_ctx *log_ctx;
+ struct vhost_iotlb *umem;
+ struct vhost_iotlb *iotlb;
+ spinlock_t iotlb_lock;
+ struct list_head read_list;
+ struct list_head pending_list;
+ wait_queue_head_t wait;
+ int iov_limit;
+ int weight;
+ int byte_weight;
+ struct xarray worker_xa;
+ bool use_worker;
+ int (*msg_handler)(struct vhost_dev *dev, u32 asid,
+ struct vhost_iotlb_msg *msg);
+};
+
+bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len);
+void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs,
+ int nvqs, int iov_limit, int weight, int byte_weight,
+ bool use_worker,
+ int (*msg_handler)(struct vhost_dev *dev, u32 asid,
+ struct vhost_iotlb_msg *msg));
+long vhost_dev_set_owner(struct vhost_dev *dev);
+bool vhost_dev_has_owner(struct vhost_dev *dev);
+long vhost_dev_check_owner(struct vhost_dev *);
+struct vhost_iotlb *vhost_dev_reset_owner_prepare(void);
+void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb);
+void vhost_dev_cleanup(struct vhost_dev *);
+void vhost_dev_stop(struct vhost_dev *);
+long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp);
+long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp);
+long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl,
+ void __user *argp);
+bool vhost_vq_access_ok(struct vhost_virtqueue *vq);
+bool vhost_log_access_ok(struct vhost_dev *);
+void vhost_clear_msg(struct vhost_dev *dev);
+
+int vhost_get_vq_desc(struct vhost_virtqueue *,
+ struct iovec iov[], unsigned int iov_size,
+ unsigned int *out_num, unsigned int *in_num,
+ struct vhost_log *log, unsigned int *log_num);
+void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
+
+void vhost_vq_flush(struct vhost_virtqueue *vq);
+bool vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work);
+bool vhost_vq_has_work(struct vhost_virtqueue *vq);
+bool vhost_vq_is_setup(struct vhost_virtqueue *vq);
+int vhost_vq_init_access(struct vhost_virtqueue *);
+int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len);
+int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,
+ unsigned count);
+void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *,
+ unsigned int id, int len);
+void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *,
+ struct vring_used_elem *heads, unsigned count);
+void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *);
+void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *);
+bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *);
+bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *);
+
+int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log,
+ unsigned int log_num, u64 len,
+ struct iovec *iov, int count);
+int vq_meta_prefetch(struct vhost_virtqueue *vq);
+
+struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type);
+void vhost_enqueue_msg(struct vhost_dev *dev,
+ struct list_head *head,
+ struct vhost_msg_node *node);
+struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev,
+ struct list_head *head);
+void vhost_set_backend_features(struct vhost_dev *dev, u64 features);
+
+__poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev,
+ poll_table *wait);
+ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to,
+ int noblock);
+ssize_t vhost_chr_write_iter(struct vhost_dev *dev,
+ struct iov_iter *from);
+int vhost_init_device_iotlb(struct vhost_dev *d);
+
+void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,
+ struct vhost_iotlb_map *map);
+
+#define vq_err(vq, fmt, ...) do { \
+ pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
+ if ((vq)->error_ctx) \
+ eventfd_signal((vq)->error_ctx, 1);\
+ } while (0)
+
+enum {
+ VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
+ (1ULL << VIRTIO_RING_F_INDIRECT_DESC) |
+ (1ULL << VIRTIO_RING_F_EVENT_IDX) |
+ (1ULL << VHOST_F_LOG_ALL) |
+ (1ULL << VIRTIO_F_ANY_LAYOUT) |
+ (1ULL << VIRTIO_F_VERSION_1)
+};
+
+/**
+ * vhost_vq_set_backend - Set backend.
+ *
+ * @vq Virtqueue.
+ * @private_data The private data.
+ *
+ * Context: Need to call with vq->mutex acquired.
+ */
+static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq,
+ void *private_data)
+{
+ vq->private_data = private_data;
+}
+
+/**
+ * vhost_vq_get_backend - Get backend.
+ *
+ * @vq Virtqueue.
+ *
+ * Context: Need to call with vq->mutex acquired.
+ * Return: Private data previously set with vhost_vq_set_backend.
+ */
+static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq)
+{
+ return vq->private_data;
+}
+
+static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit)
+{
+ return vq->acked_features & (1ULL << bit);
+}
+
+static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit)
+{
+ return vq->acked_backend_features & (1ULL << bit);
+}
+
+#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
+static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
+{
+ return vq->is_le;
+}
+#else
+static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq)
+{
+ return virtio_legacy_is_little_endian() || vq->is_le;
+}
+#endif
+
+/* Memory accessors */
+static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val)
+{
+ return __virtio16_to_cpu(vhost_is_little_endian(vq), val);
+}
+
+static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val)
+{
+ return __cpu_to_virtio16(vhost_is_little_endian(vq), val);
+}
+
+static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val)
+{
+ return __virtio32_to_cpu(vhost_is_little_endian(vq), val);
+}
+
+static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val)
+{
+ return __cpu_to_virtio32(vhost_is_little_endian(vq), val);
+}
+
+static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val)
+{
+ return __virtio64_to_cpu(vhost_is_little_endian(vq), val);
+}
+
+static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val)
+{
+ return __cpu_to_virtio64(vhost_is_little_endian(vq), val);
+}
+#endif