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28 * $FreeBSD: src/sys/dev/virtio/virtio.h,v 1.2 2011/12/06 06:28:32 grehan Exp $
34 #include <sys/types.h>
35 #include <sys/serialize.h>
39 /* VirtIO device IDs. */
40 #define VIRTIO_ID_NETWORK 0x01
41 #define VIRTIO_ID_BLOCK 0x02
42 #define VIRTIO_ID_CONSOLE 0x03
43 #define VIRTIO_ID_ENTROPY 0x04
44 #define VIRTIO_ID_BALLOON 0x05
45 #define VIRTIO_ID_IOMEMORY 0x06
46 #define VIRTIO_ID_SCSI 0x08
47 #define VIRTIO_ID_9P 0x09
49 /* Status byte for guest to report progress. */
50 #define VIRTIO_CONFIG_STATUS_RESET 0x00
51 #define VIRTIO_CONFIG_STATUS_ACK 0x01
52 #define VIRTIO_CONFIG_STATUS_DRIVER 0x02
53 #define VIRTIO_CONFIG_STATUS_DRIVER_OK 0x04
54 #define VIRTIO_CONFIG_STATUS_DEVICE_NEEDS_RESET 0x40
55 #define VIRTIO_CONFIG_STATUS_FAILED 0x80
58 * Generate interrupt when the virtqueue ring is
59 * completely used, even if we've suppressed them.
61 #define VIRTIO_F_NOTIFY_ON_EMPTY (1 << 24)
63 /* The device accepts arbitrary descriptor layouts */
64 #define VIRTIO_F_ANY_LAYOUT (1 << 27)
67 * The guest should never negotiate this feature; it
68 * is used to detect faulty drivers.
70 #define VIRTIO_F_BAD_FEATURE (1 << 30)
73 * Some VirtIO feature bits (currently bits 28 through 31) are
74 * reserved for the transport being used (eg. virtio_ring), the
75 * rest are per-device feature bits.
77 #define VIRTIO_TRANSPORT_F_START 28
78 #define VIRTIO_TRANSPORT_F_END 32
81 * Maximum number of virtqueues per device.
83 #define VIRTIO_MAX_VIRTQUEUES 8
86 * XXX malloc(9) comment not correct on DragonFly
87 * Each virtqueue indirect descriptor list must be physically contiguous.
88 * To allow us to malloc(9) each list individually, limit the number
89 * supported to what will fit in one page. With 4KB pages, this is a limit
90 * of 256 descriptors. If there is ever a need for more, we can switch to
91 * contigmalloc(9) for the larger allocations, similar to what
92 * bus_dmamem_alloc(9) does.
94 * Note the sizeof(struct vring_desc) is 16 bytes.
96 #define VIRTIO_MAX_INDIRECT ((int) (PAGE_SIZE / 16))
99 * VirtIO instance variables indices.
101 #define VIRTIO_IVAR_DEVTYPE 1
102 #define VIRTIO_IVAR_FEATURE_DESC 2
104 struct virtio_feature_desc {
109 const char *virtio_device_name(uint16_t devid);
110 int virtio_get_device_type(device_t dev);
111 void virtio_set_feature_desc(device_t dev,
112 struct virtio_feature_desc *feature_desc);
113 void virtio_describe(device_t dev, const char *msg,
114 uint64_t features, struct virtio_feature_desc *feature_desc);
117 * VirtIO Bus Methods.
119 uint64_t virtio_negotiate_features(device_t dev, uint64_t child_features);
120 int virtio_alloc_virtqueues(device_t dev, int nvqs,
121 struct vq_alloc_info *info);
122 /* Allocate the interrupt resources. */
124 * The cpus array must be allocated, and contains -1 or cpuid for each IRQ.
126 * This will either allocate all the irqs, and fill in the actual cpus, and
127 * return 0, or it will fail and return the number of irq vectors that it
128 * managed to get before aborting in "int *cnt".
129 * The driver is supposed to check whether the chosen cpu cores match
132 * Driver should specify use_config as 1, if a configuration should be
133 * preferred, where the configuration change notification can be handled
134 * efficiently. This only takes effect when a more efficient
136 * Fails if any interrupts are already allocated.
137 * Caller should check *cnt value after call, to check if all requested IRQS
138 * were actually allocated.
140 int virtio_intr_alloc(device_t dev, int *cnt, int use_config, int *cpus);
141 /* Release all the interrupts, fails if any is currently in use */
142 int virtio_intr_release(device_t dev);
143 /* Activate a hardware interrupt. */
144 int virtio_setup_intr(device_t dev, uint irq, lwkt_serialize_t);
145 int virtio_teardown_intr(device_t dev, uint irq);
147 * Bind the config-notification (-1), or a virtqueue (>= 0) to the irq.
149 * If the IRQ is an MSI-X, which is also mapped to a virtqueue, the driver
150 * will get a notification callback on each interrupt, whereas if irq is a
151 * legacy IRQ, the virtio device can check the ISR to determine if the
152 * configuration was updated.
154 int virtio_bind_intr(device_t dev, uint irq, int what,
155 driver_intr_t handler, void *arg);
156 /* Similarly, -1 is the notification IRQ, >= 0 are the virtqueues. */
157 int virtio_unbind_intr(device_t dev, int what);
158 int virtio_with_feature(device_t dev, uint64_t feature);
159 /* Get number of interrupts that can probably be allocated. */
160 int virtio_intr_count(device_t dev);
161 void virtio_stop(device_t dev);
162 int virtio_reinit(device_t dev, uint64_t features);
163 void virtio_reinit_complete(device_t dev);
166 * Read/write a variable amount from the device specific (ie, network)
167 * configuration region. This region is encoded in the same endian as
170 void virtio_read_device_config(device_t dev, bus_size_t offset,
171 void *dst, int length);
172 void virtio_write_device_config(device_t dev, bus_size_t offset,
173 void *src, int length);
175 /* Inlined device specific read/write functions for common lengths. */
176 #define VIRTIO_RDWR_DEVICE_CONFIG(size, type) \
178 __CONCAT(virtio_read_dev_config_,size)(device_t dev, \
182 virtio_read_device_config(dev, offset, &val, sizeof(type)); \
187 __CONCAT(virtio_write_dev_config_,size)(device_t dev, \
188 bus_size_t offset, type val) \
190 virtio_write_device_config(dev, offset, &val, sizeof(type)); \
193 VIRTIO_RDWR_DEVICE_CONFIG(1, uint8_t);
194 VIRTIO_RDWR_DEVICE_CONFIG(2, uint16_t);
195 VIRTIO_RDWR_DEVICE_CONFIG(4, uint32_t);
197 #endif /* _VIRTIO_H_ */