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