#include "hw/virtio/virtio.h"
#include "exec/memory.h"
+#define VHOST_F_DEVICE_IOTLB 63
+#define VHOST_USER_F_PROTOCOL_FEATURES 30
+
+#define VU_REALIZE_CONN_RETRIES 3
+
/* Generic structures common for any vhost based device. */
struct vhost_inflight {
unsigned long long used_phys;
unsigned used_size;
EventNotifier masked_notifier;
+ EventNotifier error_notifier;
+ EventNotifier masked_config_notifier;
struct vhost_dev *dev;
};
#define VHOST_LOG_BITS (8 * sizeof(vhost_log_chunk_t))
#define VHOST_LOG_CHUNK (VHOST_LOG_PAGE * VHOST_LOG_BITS)
#define VHOST_INVALID_FEATURE_BIT (0xff)
+#define VHOST_QUEUE_NUM_CONFIG_INR 0
struct vhost_log {
unsigned long long size;
} VhostDevConfigOps;
struct vhost_memory;
+
+/**
+ * struct vhost_dev - common vhost_dev structure
+ * @vhost_ops: backend specific ops
+ * @config_ops: ops for config changes (see @vhost_dev_set_config_notifier)
+ */
struct vhost_dev {
VirtIODevice *vdev;
MemoryListener memory_listener;
int vq_index_end;
/* if non-zero, minimum required value for max_queues */
int num_queues;
+ /**
+ * vhost feature handling requires matching the feature set
+ * offered by a backend which may be a subset of the total
+ * features eventually offered to the guest.
+ *
+ * @features: available features provided by the backend
+ * @acked_features: final negotiated features with front-end driver
+ *
+ * @backend_features: this is used in a couple of places to either
+ * store VHOST_USER_F_PROTOCOL_FEATURES to apply to
+ * VHOST_USER_SET_FEATURES or VHOST_NET_F_VIRTIO_NET_HDR. Its
+ * future use should be discouraged and the variable retired as
+ * its easy to confuse with the VirtIO backend_features.
+ */
uint64_t features;
uint64_t acked_features;
uint64_t backend_features;
+
+ /**
+ * @protocol_features: is the vhost-user only feature set by
+ * VHOST_USER_SET_PROTOCOL_FEATURES. Protocol features are only
+ * negotiated if VHOST_USER_F_PROTOCOL_FEATURES has been offered
+ * by the backend (see @features).
+ */
uint64_t protocol_features;
+
uint64_t max_queues;
uint64_t backend_cap;
+ /* @started: is the vhost device started? */
bool started;
bool log_enabled;
uint64_t log_size;
NetClientState *nc;
};
+/**
+ * vhost_dev_init() - initialise the vhost interface
+ * @hdev: the common vhost_dev structure
+ * @opaque: opaque ptr passed to backend (vhost/vhost-user/vdpa)
+ * @backend_type: type of backend
+ * @busyloop_timeout: timeout for polling virtqueue
+ * @errp: error handle
+ *
+ * The initialisation of the vhost device will trigger the
+ * initialisation of the backend and potentially capability
+ * negotiation of backend interface. Configuration of the VirtIO
+ * itself won't happen until the interface is started.
+ *
+ * Return: 0 on success, non-zero on error while setting errp.
+ */
int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
VhostBackendType backend_type,
uint32_t busyloop_timeout, Error **errp);
+
+/**
+ * vhost_dev_cleanup() - tear down and cleanup vhost interface
+ * @hdev: the common vhost_dev structure
+ */
void vhost_dev_cleanup(struct vhost_dev *hdev);
-int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
-void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
+
+/**
+ * vhost_dev_enable_notifiers() - enable event notifiers
+ * @hdev: common vhost_dev structure
+ * @vdev: the VirtIODevice structure
+ *
+ * Enable notifications directly to the vhost device rather than being
+ * triggered by QEMU itself. Notifications should be enabled before
+ * the vhost device is started via @vhost_dev_start.
+ *
+ * Return: 0 on success, < 0 on error.
+ */
int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
+
+/**
+ * vhost_dev_disable_notifiers - disable event notifications
+ * @hdev: common vhost_dev structure
+ * @vdev: the VirtIODevice structure
+ *
+ * Disable direct notifications to vhost device.
+ */
void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
+bool vhost_config_pending(struct vhost_dev *hdev);
+void vhost_config_mask(struct vhost_dev *hdev, VirtIODevice *vdev, bool mask);
+
+/**
+ * vhost_dev_is_started() - report status of vhost device
+ * @hdev: common vhost_dev structure
+ *
+ * Return the started status of the vhost device
+ */
+static inline bool vhost_dev_is_started(struct vhost_dev *hdev)
+{
+ return hdev->started;
+}
+
+/**
+ * vhost_dev_start() - start the vhost device
+ * @hdev: common vhost_dev structure
+ * @vdev: the VirtIODevice structure
+ * @vrings: true to have vrings enabled in this call
+ *
+ * Starts the vhost device. From this point VirtIO feature negotiation
+ * can start and the device can start processing VirtIO transactions.
+ *
+ * Return: 0 on success, < 0 on error.
+ */
+int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
+
+/**
+ * vhost_dev_stop() - stop the vhost device
+ * @hdev: common vhost_dev structure
+ * @vdev: the VirtIODevice structure
+ * @vrings: true to have vrings disabled in this call
+ *
+ * Stop the vhost device. After the device is stopped the notifiers
+ * can be disabled (@vhost_dev_disable_notifiers) and the device can
+ * be torn down (@vhost_dev_cleanup).
+ */
+void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings);
+
+/**
+ * DOC: vhost device configuration handling
+ *
+ * The VirtIO device configuration space is used for rarely changing
+ * or initialisation time parameters. The configuration can be updated
+ * by either the guest driver or the device itself. If the device can
+ * change the configuration over time the vhost handler should
+ * register a @VhostDevConfigOps structure with
+ * @vhost_dev_set_config_notifier so the guest can be notified. Some
+ * devices register a handler anyway and will signal an error if an
+ * unexpected config change happens.
+ */
+
+/**
+ * vhost_dev_get_config() - fetch device configuration
+ * @hdev: common vhost_dev_structure
+ * @config: pointer to device appropriate config structure
+ * @config_len: size of device appropriate config structure
+ *
+ * Return: 0 on success, < 0 on error while setting errp
+ */
+int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
+ uint32_t config_len, Error **errp);
+
+/**
+ * vhost_dev_set_config() - set device configuration
+ * @hdev: common vhost_dev_structure
+ * @data: pointer to data to set
+ * @offset: offset into configuration space
+ * @size: length of set
+ * @flags: @VhostSetConfigType flags
+ *
+ * By use of @offset/@size a subset of the configuration space can be
+ * written to. The @flags are used to indicate if it is a normal
+ * transaction or related to migration.
+ *
+ * Return: 0 on success, non-zero on error
+ */
+int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
+ uint32_t offset, uint32_t size, uint32_t flags);
+
+/**
+ * vhost_dev_set_config_notifier() - register VhostDevConfigOps
+ * @hdev: common vhost_dev_structure
+ * @ops: notifier ops
+ *
+ * If the device is expected to change configuration a notifier can be
+ * setup to handle the case.
+ */
+void vhost_dev_set_config_notifier(struct vhost_dev *dev,
+ const VhostDevConfigOps *ops);
+
/* Test and clear masked event pending status.
* Should be called after unmask to avoid losing events.
*/
void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n,
bool mask);
+
+/**
+ * vhost_get_features() - return a sanitised set of feature bits
+ * @hdev: common vhost_dev structure
+ * @feature_bits: pointer to terminated table of feature bits
+ * @features: original feature set
+ *
+ * This returns a set of features bits that is an intersection of what
+ * is supported by the vhost backend (hdev->features), the supported
+ * feature_bits and the requested feature set.
+ */
uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bits,
uint64_t features);
+
+/**
+ * vhost_ack_features() - set vhost acked_features
+ * @hdev: common vhost_dev structure
+ * @feature_bits: pointer to terminated table of feature bits
+ * @features: requested feature set
+ *
+ * This sets the internal hdev->acked_features to the intersection of
+ * the backends advertised features and the supported feature_bits.
+ */
void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits,
uint64_t features);
-bool vhost_has_free_slot(void);
+unsigned int vhost_get_max_memslots(void);
+unsigned int vhost_get_free_memslots(void);
int vhost_net_set_backend(struct vhost_dev *hdev,
struct vhost_vring_file *file);
+void vhost_toggle_device_iotlb(VirtIODevice *vdev);
int vhost_device_iotlb_miss(struct vhost_dev *dev, uint64_t iova, int write);
-int vhost_dev_get_config(struct vhost_dev *hdev, uint8_t *config,
- uint32_t config_len, Error **errp);
-int vhost_dev_set_config(struct vhost_dev *dev, const uint8_t *data,
- uint32_t offset, uint32_t size, uint32_t flags);
-/* notifier callback in case vhost device config space changed
- */
-void vhost_dev_set_config_notifier(struct vhost_dev *dev,
- const VhostDevConfigOps *ops);
+
+int vhost_virtqueue_start(struct vhost_dev *dev, struct VirtIODevice *vdev,
+ struct vhost_virtqueue *vq, unsigned idx);
+void vhost_virtqueue_stop(struct vhost_dev *dev, struct VirtIODevice *vdev,
+ struct vhost_virtqueue *vq, unsigned idx);
void vhost_dev_reset_inflight(struct vhost_inflight *inflight);
void vhost_dev_free_inflight(struct vhost_inflight *inflight);
struct vhost_inflight *inflight);
int vhost_dev_get_inflight(struct vhost_dev *dev, uint16_t queue_size,
struct vhost_inflight *inflight);
+bool vhost_dev_has_iommu(struct vhost_dev *dev);
+
+#ifdef CONFIG_VHOST
+int vhost_reset_device(struct vhost_dev *hdev);
+#else
+static inline int vhost_reset_device(struct vhost_dev *hdev)
+{
+ return -ENOSYS;
+}
+#endif /* CONFIG_VHOST */
+
+/**
+ * vhost_supports_device_state(): Checks whether the back-end supports
+ * transferring internal device state for the purpose of migration.
+ * Support for this feature is required for vhost_set_device_state_fd()
+ * and vhost_check_device_state().
+ *
+ * @dev: The vhost device
+ *
+ * Returns true if the device supports these commands, and false if it
+ * does not.
+ */
+bool vhost_supports_device_state(struct vhost_dev *dev);
+
+/**
+ * vhost_set_device_state_fd(): Begin transfer of internal state from/to
+ * the back-end for the purpose of migration. Data is to be transferred
+ * over a pipe according to @direction and @phase. The sending end must
+ * only write to the pipe, and the receiving end must only read from it.
+ * Once the sending end is done, it closes its FD. The receiving end
+ * must take this as the end-of-transfer signal and close its FD, too.
+ *
+ * @fd is the back-end's end of the pipe: The write FD for SAVE, and the
+ * read FD for LOAD. This function transfers ownership of @fd to the
+ * back-end, i.e. closes it in the front-end.
+ *
+ * The back-end may optionally reply with an FD of its own, if this
+ * improves efficiency on its end. In this case, the returned FD is
+ * stored in *reply_fd. The back-end will discard the FD sent to it,
+ * and the front-end must use *reply_fd for transferring state to/from
+ * the back-end.
+ *
+ * @dev: The vhost device
+ * @direction: The direction in which the state is to be transferred.
+ * For outgoing migrations, this is SAVE, and data is read
+ * from the back-end and stored by the front-end in the
+ * migration stream.
+ * For incoming migrations, this is LOAD, and data is read
+ * by the front-end from the migration stream and sent to
+ * the back-end to restore the saved state.
+ * @phase: Which migration phase we are in. Currently, there is only
+ * STOPPED (device and all vrings are stopped), in the future,
+ * more phases such as PRE_COPY or POST_COPY may be added.
+ * @fd: Back-end's end of the pipe through which to transfer state; note
+ * that ownership is transferred to the back-end, so this function
+ * closes @fd in the front-end.
+ * @reply_fd: If the back-end wishes to use a different pipe for state
+ * transfer, this will contain an FD for the front-end to
+ * use. Otherwise, -1 is stored here.
+ * @errp: Potential error description
+ *
+ * Returns 0 on success, and -errno on failure.
+ */
+int vhost_set_device_state_fd(struct vhost_dev *dev,
+ VhostDeviceStateDirection direction,
+ VhostDeviceStatePhase phase,
+ int fd,
+ int *reply_fd,
+ Error **errp);
+
+/**
+ * vhost_set_device_state_fd(): After transferring state from/to the
+ * back-end via vhost_set_device_state_fd(), i.e. once the sending end
+ * has closed the pipe, inquire the back-end to report any potential
+ * errors that have occurred on its side. This allows to sense errors
+ * like:
+ * - During outgoing migration, when the source side had already started
+ * to produce its state, something went wrong and it failed to finish
+ * - During incoming migration, when the received state is somehow
+ * invalid and cannot be processed by the back-end
+ *
+ * @dev: The vhost device
+ * @errp: Potential error description
+ *
+ * Returns 0 when the back-end reports successful state transfer and
+ * processing, and -errno when an error occurred somewhere.
+ */
+int vhost_check_device_state(struct vhost_dev *dev, Error **errp);
+
+/**
+ * vhost_save_backend_state(): High-level function to receive a vhost
+ * back-end's state, and save it in @f. Uses
+ * `vhost_set_device_state_fd()` to get the data from the back-end, and
+ * stores it in consecutive chunks that are each prefixed by their
+ * respective length (be32). The end is marked by a 0-length chunk.
+ *
+ * Must only be called while the device and all its vrings are stopped
+ * (`VHOST_TRANSFER_STATE_PHASE_STOPPED`).
+ *
+ * @dev: The vhost device from which to save the state
+ * @f: Migration stream in which to save the state
+ * @errp: Potential error message
+ *
+ * Returns 0 on success, and -errno otherwise.
+ */
+int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp);
+
+/**
+ * vhost_load_backend_state(): High-level function to load a vhost
+ * back-end's state from @f, and send it over to the back-end. Reads
+ * the data from @f in the format used by `vhost_save_state()`, and uses
+ * `vhost_set_device_state_fd()` to transfer it to the back-end.
+ *
+ * Must only be called while the device and all its vrings are stopped
+ * (`VHOST_TRANSFER_STATE_PHASE_STOPPED`).
+ *
+ * @dev: The vhost device to which to send the state
+ * @f: Migration stream from which to load the state
+ * @errp: Potential error message
+ *
+ * Returns 0 on success, and -errno otherwise.
+ */
+int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp);
+
#endif
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