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