qemu

vmbus.h (7234B)

---

 /*
  * QEMU Hyper-V VMBus
  *
  * Copyright (c) 2017-2018 Virtuozzo International GmbH.
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  */
 
 #ifndef HW_HYPERV_VMBUS_H
 #define HW_HYPERV_VMBUS_H
 
 #include "sysemu/sysemu.h"
 #include "sysemu/dma.h"
 #include "hw/qdev-core.h"
 #include "migration/vmstate.h"
 #include "hw/hyperv/vmbus-proto.h"
 #include "qemu/uuid.h"
 #include "qom/object.h"
 
 #define TYPE_VMBUS_DEVICE "vmbus-dev"
 
 OBJECT_DECLARE_TYPE(VMBusDevice, VMBusDeviceClass,
                     VMBUS_DEVICE)
 
 #define TYPE_VMBUS "vmbus"
 OBJECT_DECLARE_SIMPLE_TYPE(VMBus, VMBUS)
 
 /*
  * Object wrapping a GPADL -- GPA Descriptor List -- an array of guest physical
  * pages, to be used for various buffers shared between the host and the guest.
  */
 typedef struct VMBusGpadl VMBusGpadl;
 /*
  * VMBus channel -- a pair of ring buffers for either direction, placed within
  * one GPADL, and the associated notification means.
  */
 typedef struct VMBusChannel VMBusChannel;
 /*
  * Base class for VMBus devices.  Includes one or more channels.  Identified by
  * class GUID and instance GUID.
  */
 
 typedef void(*VMBusChannelNotifyCb)(struct VMBusChannel *chan);
 
 struct VMBusDeviceClass {
     DeviceClass parent;
 
     QemuUUID classid;
     QemuUUID instanceid;     /* Fixed UUID for singleton devices */
     uint16_t channel_flags;
     uint16_t mmio_size_mb;
 
     /* Extentions to standard device callbacks */
     void (*vmdev_realize)(VMBusDevice *vdev, Error **errp);
     void (*vmdev_unrealize)(VMBusDevice *vdev);
     void (*vmdev_reset)(VMBusDevice *vdev);
     /*
      * Calculate the number of channels based on the device properties.  Called
      * at realize time.
      **/
     uint16_t (*num_channels)(VMBusDevice *vdev);
     /*
      * Device-specific actions to complete the otherwise successful process of
      * opening a channel.
      * Return 0 on success, -errno on failure.
      */
     int (*open_channel)(VMBusChannel *chan);
     /*
      * Device-specific actions to perform before closing a channel.
      */
     void (*close_channel)(VMBusChannel *chan);
     /*
      * Main device worker; invoked in response to notifications from either
      * side, when there's work to do with the data in the channel ring buffers.
      */
     VMBusChannelNotifyCb chan_notify_cb;
 };
 
 struct VMBusDevice {
     DeviceState parent;
     QemuUUID instanceid;
     uint16_t num_channels;
     VMBusChannel *channels;
     AddressSpace *dma_as;
 };
 
 extern const VMStateDescription vmstate_vmbus_dev;
 
 /*
  * A unit of work parsed out of a message in the receive (i.e. guest->host)
  * ring buffer of a channel.  It's supposed to be subclassed (through
  * embedding) by the specific devices.
  */
 typedef struct VMBusChanReq {
     VMBusChannel *chan;
     uint16_t pkt_type;
     uint32_t msglen;
     void *msg;
     uint64_t transaction_id;
     bool need_comp;
     QEMUSGList sgl;
 } VMBusChanReq;
 
 VMBusDevice *vmbus_channel_device(VMBusChannel *chan);
 VMBusChannel *vmbus_device_channel(VMBusDevice *dev, uint32_t chan_idx);
 uint32_t vmbus_channel_idx(VMBusChannel *chan);
 bool vmbus_channel_is_open(VMBusChannel *chan);
 
 /*
  * Notify (on guest's behalf) the host side of the channel that there's data in
  * the ringbuffer to process.
  */
 void vmbus_channel_notify_host(VMBusChannel *chan);
 
 /*
  * Reserve space for a packet in the send (i.e. host->guest) ringbuffer.  If
  * there isn't enough room, indicate that to the guest, to be notified when it
  * becomes available.
  * Return 0 on success, negative errno on failure.
  * The ringbuffer indices are NOT updated, the requested space indicator may.
  */
 int vmbus_channel_reserve(VMBusChannel *chan,
                           uint32_t desclen, uint32_t msglen);
 
 /*
  * Send a packet to the guest.  The space for the packet MUST be reserved
  * first.
  * Return total number of bytes placed in the send ringbuffer on success,
  * negative errno on failure.
  * The ringbuffer indices are updated on success, and the guest is signaled if
  * needed.
  */
 ssize_t vmbus_channel_send(VMBusChannel *chan, uint16_t pkt_type,
                            void *desc, uint32_t desclen,
                            void *msg, uint32_t msglen,
                            bool need_comp, uint64_t transaction_id);
 
 /*
  * Prepare to fetch a batch of packets from the receive ring buffer.
  * Return 0 on success, negative errno on failure.
  */
 int vmbus_channel_recv_start(VMBusChannel *chan);
 
 /*
  * Shortcut for a common case of sending a simple completion packet with no
  * auxiliary descriptors.
  */
 ssize_t vmbus_channel_send_completion(VMBusChanReq *req,
                                       void *msg, uint32_t msglen);
 
 /*
  * Peek at the receive (i.e. guest->host) ring buffer and extract a unit of
  * work (a device-specific subclass of VMBusChanReq) from a packet if there's
  * one.
  * Return an allocated buffer, containing the request of @size with filled
  * VMBusChanReq at the beginning, followed by the message payload, or NULL on
  * failure.
  * The ringbuffer indices are NOT updated, nor is the private copy of the read
  * index.
  */
 void *vmbus_channel_recv_peek(VMBusChannel *chan, uint32_t size);
 
 /*
  * Update the private copy of the read index once the preceding peek is deemed
  * successful.
  * The ringbuffer indices are NOT updated.
  */
 void vmbus_channel_recv_pop(VMBusChannel *chan);
 
 /*
  * Propagate the private copy of the read index into the receive ring buffer,
  * and thus complete the reception of a series of packets.  Notify guest if
  * needed.
  * Return the number of bytes popped off the receive ring buffer by the
  * preceding recv_peek/recv_pop calls on success, negative errno on failure.
  */
 ssize_t vmbus_channel_recv_done(VMBusChannel *chan);
 
 /*
  * Free the request allocated by vmbus_channel_recv_peek, together with its
  * fields.
  */
 void vmbus_free_req(void *req);
 
 /*
  * Find and reference a GPADL by @gpadl_id.
  * If not found return NULL.
  */
 VMBusGpadl *vmbus_get_gpadl(VMBusChannel *chan, uint32_t gpadl_id);
 
 /*
  * Unreference @gpadl.  If the reference count drops to zero, free it.
  * @gpadl may be NULL, in which case nothing is done.
  */
 void vmbus_put_gpadl(VMBusGpadl *gpadl);
 
 /*
  * Calculate total length in bytes of @gpadl.
  * @gpadl must be valid.
  */
 uint32_t vmbus_gpadl_len(VMBusGpadl *gpadl);
 
 /*
  * Copy data from @iov to @gpadl at offset @off.
  * Return the number of bytes copied, or a negative status on failure.
  */
 ssize_t vmbus_iov_to_gpadl(VMBusChannel *chan, VMBusGpadl *gpadl, uint32_t off,
                            const struct iovec *iov, size_t iov_cnt);
 
 /*
  * Map SGList contained in the request @req, at offset @off and no more than
  * @len bytes, for io in direction @dir, and populate @iov with the mapped
  * iovecs.
  * Return the number of iovecs mapped, or negative status on failure.
  */
 int vmbus_map_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov,
                   unsigned iov_cnt, size_t len, size_t off);
 
 /*
  * Unmap *iov mapped with vmbus_map_sgl, marking the number of bytes @accessed.
  */
 void vmbus_unmap_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov,
                      unsigned iov_cnt, size_t accessed);
 
 #endif