1 /* 2 * QEMU Hyper-V VMBus 3 * 4 * Copyright (c) 2017-2018 Virtuozzo International GmbH. 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or later. 7 * See the COPYING file in the top-level directory. 8 */ 9 10 #ifndef HW_HYPERV_VMBUS_H 11 #define HW_HYPERV_VMBUS_H 12 13 #include "sysemu/sysemu.h" 14 #include "sysemu/dma.h" 15 #include "hw/qdev-core.h" 16 #include "migration/vmstate.h" 17 #include "hw/hyperv/vmbus-proto.h" 18 #include "qemu/uuid.h" 19 #include "qom/object.h" 20 21 #define TYPE_VMBUS_DEVICE "vmbus-dev" 22 23 OBJECT_DECLARE_TYPE(VMBusDevice, VMBusDeviceClass, 24 vmbus_device, VMBUS_DEVICE) 25 26 #define TYPE_VMBUS "vmbus" 27 typedef struct VMBus VMBus; 28 DECLARE_INSTANCE_CHECKER(VMBus, VMBUS, 29 TYPE_VMBUS) 30 31 /* 32 * Object wrapping a GPADL -- GPA Descriptor List -- an array of guest physical 33 * pages, to be used for various buffers shared between the host and the guest. 34 */ 35 typedef struct VMBusGpadl VMBusGpadl; 36 /* 37 * VMBus channel -- a pair of ring buffers for either direction, placed within 38 * one GPADL, and the associated notification means. 39 */ 40 typedef struct VMBusChannel VMBusChannel; 41 /* 42 * Base class for VMBus devices. Includes one or more channels. Identified by 43 * class GUID and instance GUID. 44 */ 45 46 typedef void(*VMBusChannelNotifyCb)(struct VMBusChannel *chan); 47 48 struct VMBusDeviceClass { 49 DeviceClass parent; 50 51 QemuUUID classid; 52 QemuUUID instanceid; /* Fixed UUID for singleton devices */ 53 uint16_t channel_flags; 54 uint16_t mmio_size_mb; 55 56 /* Extentions to standard device callbacks */ 57 void (*vmdev_realize)(VMBusDevice *vdev, Error **errp); 58 void (*vmdev_unrealize)(VMBusDevice *vdev); 59 void (*vmdev_reset)(VMBusDevice *vdev); 60 /* 61 * Calculate the number of channels based on the device properties. Called 62 * at realize time. 63 **/ 64 uint16_t (*num_channels)(VMBusDevice *vdev); 65 /* 66 * Device-specific actions to complete the otherwise successful process of 67 * opening a channel. 68 * Return 0 on success, -errno on failure. 69 */ 70 int (*open_channel)(VMBusChannel *chan); 71 /* 72 * Device-specific actions to perform before closing a channel. 73 */ 74 void (*close_channel)(VMBusChannel *chan); 75 /* 76 * Main device worker; invoked in response to notifications from either 77 * side, when there's work to do with the data in the channel ring buffers. 78 */ 79 VMBusChannelNotifyCb chan_notify_cb; 80 }; 81 82 struct VMBusDevice { 83 DeviceState parent; 84 QemuUUID instanceid; 85 uint16_t num_channels; 86 VMBusChannel *channels; 87 AddressSpace *dma_as; 88 }; 89 90 extern const VMStateDescription vmstate_vmbus_dev; 91 92 /* 93 * A unit of work parsed out of a message in the receive (i.e. guest->host) 94 * ring buffer of a channel. It's supposed to be subclassed (through 95 * embedding) by the specific devices. 96 */ 97 typedef struct VMBusChanReq { 98 VMBusChannel *chan; 99 uint16_t pkt_type; 100 uint32_t msglen; 101 void *msg; 102 uint64_t transaction_id; 103 bool need_comp; 104 QEMUSGList sgl; 105 } VMBusChanReq; 106 107 VMBusDevice *vmbus_channel_device(VMBusChannel *chan); 108 VMBusChannel *vmbus_device_channel(VMBusDevice *dev, uint32_t chan_idx); 109 uint32_t vmbus_channel_idx(VMBusChannel *chan); 110 bool vmbus_channel_is_open(VMBusChannel *chan); 111 112 /* 113 * Notify (on guest's behalf) the host side of the channel that there's data in 114 * the ringbuffer to process. 115 */ 116 void vmbus_channel_notify_host(VMBusChannel *chan); 117 118 /* 119 * Reserve space for a packet in the send (i.e. host->guest) ringbuffer. If 120 * there isn't enough room, indicate that to the guest, to be notified when it 121 * becomes available. 122 * Return 0 on success, negative errno on failure. 123 * The ringbuffer indices are NOT updated, the requested space indicator may. 124 */ 125 int vmbus_channel_reserve(VMBusChannel *chan, 126 uint32_t desclen, uint32_t msglen); 127 128 /* 129 * Send a packet to the guest. The space for the packet MUST be reserved 130 * first. 131 * Return total number of bytes placed in the send ringbuffer on success, 132 * negative errno on failure. 133 * The ringbuffer indices are updated on success, and the guest is signaled if 134 * needed. 135 */ 136 ssize_t vmbus_channel_send(VMBusChannel *chan, uint16_t pkt_type, 137 void *desc, uint32_t desclen, 138 void *msg, uint32_t msglen, 139 bool need_comp, uint64_t transaction_id); 140 141 /* 142 * Prepare to fetch a batch of packets from the receive ring buffer. 143 * Return 0 on success, negative errno on failure. 144 */ 145 int vmbus_channel_recv_start(VMBusChannel *chan); 146 147 /* 148 * Shortcut for a common case of sending a simple completion packet with no 149 * auxiliary descriptors. 150 */ 151 ssize_t vmbus_channel_send_completion(VMBusChanReq *req, 152 void *msg, uint32_t msglen); 153 154 /* 155 * Peek at the receive (i.e. guest->host) ring buffer and extract a unit of 156 * work (a device-specific subclass of VMBusChanReq) from a packet if there's 157 * one. 158 * Return an allocated buffer, containing the request of @size with filled 159 * VMBusChanReq at the beginning, followed by the message payload, or NULL on 160 * failure. 161 * The ringbuffer indices are NOT updated, nor is the private copy of the read 162 * index. 163 */ 164 void *vmbus_channel_recv_peek(VMBusChannel *chan, uint32_t size); 165 166 /* 167 * Update the private copy of the read index once the preceding peek is deemed 168 * successful. 169 * The ringbuffer indices are NOT updated. 170 */ 171 void vmbus_channel_recv_pop(VMBusChannel *chan); 172 173 /* 174 * Propagate the private copy of the read index into the receive ring buffer, 175 * and thus complete the reception of a series of packets. Notify guest if 176 * needed. 177 * Return the number of bytes popped off the receive ring buffer by the 178 * preceding recv_peek/recv_pop calls on success, negative errno on failure. 179 */ 180 ssize_t vmbus_channel_recv_done(VMBusChannel *chan); 181 182 /* 183 * Free the request allocated by vmbus_channel_recv_peek, together with its 184 * fields. 185 */ 186 void vmbus_free_req(void *req); 187 188 /* 189 * Find and reference a GPADL by @gpadl_id. 190 * If not found return NULL. 191 */ 192 VMBusGpadl *vmbus_get_gpadl(VMBusChannel *chan, uint32_t gpadl_id); 193 194 /* 195 * Unreference @gpadl. If the reference count drops to zero, free it. 196 * @gpadl may be NULL, in which case nothing is done. 197 */ 198 void vmbus_put_gpadl(VMBusGpadl *gpadl); 199 200 /* 201 * Calculate total length in bytes of @gpadl. 202 * @gpadl must be valid. 203 */ 204 uint32_t vmbus_gpadl_len(VMBusGpadl *gpadl); 205 206 /* 207 * Copy data from @iov to @gpadl at offset @off. 208 * Return the number of bytes copied, or a negative status on failure. 209 */ 210 ssize_t vmbus_iov_to_gpadl(VMBusChannel *chan, VMBusGpadl *gpadl, uint32_t off, 211 const struct iovec *iov, size_t iov_cnt); 212 213 /* 214 * Map SGList contained in the request @req, at offset @off and no more than 215 * @len bytes, for io in direction @dir, and populate @iov with the mapped 216 * iovecs. 217 * Return the number of iovecs mapped, or negative status on failure. 218 */ 219 int vmbus_map_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov, 220 unsigned iov_cnt, size_t len, size_t off); 221 222 /* 223 * Unmap *iov mapped with vmbus_map_sgl, marking the number of bytes @accessed. 224 */ 225 void vmbus_unmap_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov, 226 unsigned iov_cnt, size_t accessed); 227 228 void vmbus_save_req(QEMUFile *f, VMBusChanReq *req); 229 void *vmbus_load_req(QEMUFile *f, VMBusDevice *dev, uint32_t size); 230 231 #endif 232