jcs.org
qemu with hax to log dma reads & writes
jcs.org/2018/11/12/vfio
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 */
33typedef 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 */
38typedef struct VMBusChannel VMBusChannel;
39/*
40 * Base class for VMBus devices. Includes one or more channels. Identified by
41 * class GUID and instance GUID.
42 */
43typedef struct VMBusDevice VMBusDevice;
44
45typedef void(*VMBusChannelNotifyCb)(struct VMBusChannel *chan);
46
47typedef 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
81struct VMBusDevice {
82 DeviceState parent;
83 QemuUUID instanceid;
84 uint16_t num_channels;
85 VMBusChannel *channels;
86 AddressSpace *dma_as;
87};
88
89extern 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 */
96typedef 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
106VMBusDevice *vmbus_channel_device(VMBusChannel *chan);
107VMBusChannel *vmbus_device_channel(VMBusDevice *dev, uint32_t chan_idx);
108uint32_t vmbus_channel_idx(VMBusChannel *chan);
109bool 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 */
115void 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 */
124int 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 */
135ssize_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 */
144int 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 */
150ssize_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 */
163void *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 */
170void 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 */
179ssize_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 */
185void vmbus_free_req(void *req);
186
187/*
188 * Find and reference a GPADL by @gpadl_id.
189 * If not found return NULL.
190 */
191VMBusGpadl *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 */
197void vmbus_put_gpadl(VMBusGpadl *gpadl);
198
199/*
200 * Calculate total length in bytes of @gpadl.
201 * @gpadl must be valid.
202 */
203uint32_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 */
209ssize_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 */
218int 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 */
224void vmbus_unmap_sgl(VMBusChanReq *req, DMADirection dir, struct iovec *iov,
225 unsigned iov_cnt, size_t accessed);
226
227void vmbus_save_req(QEMUFile *f, VMBusChanReq *req);
228void *vmbus_load_req(QEMUFile *f, VMBusDevice *dev, uint32_t size);
229
230#endif