1 /*
2  * libqos virtio definitions
3  *
4  * Copyright (c) 2014 Marc Marí
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 LIBQOS_VIRTIO_H
11 #define LIBQOS_VIRTIO_H
12 
13 #include "libqos/malloc.h"
14 #include "standard-headers/linux/virtio_ring.h"
15 
16 #define QVIRTIO_F_BAD_FEATURE           0x40000000
17 
18 typedef struct QVirtioBus QVirtioBus;
19 
20 typedef struct QVirtioDevice {
21     const QVirtioBus *bus;
22     /* Device type */
23     uint16_t device_type;
24 } QVirtioDevice;
25 
26 typedef struct QVirtQueue {
27     uint64_t desc; /* This points to an array of struct vring_desc */
28     uint64_t avail; /* This points to a struct vring_avail */
29     uint64_t used; /* This points to a struct vring_used */
30     uint16_t index;
31     uint32_t size;
32     uint32_t free_head;
33     uint32_t num_free;
34     uint32_t align;
35     uint16_t last_used_idx;
36     bool indirect;
37     bool event;
38 } QVirtQueue;
39 
40 typedef struct QVRingIndirectDesc {
41     uint64_t desc; /* This points to an array fo struct vring_desc */
42     uint16_t index;
43     uint16_t elem;
44 } QVRingIndirectDesc;
45 
46 struct QVirtioBus {
47     uint8_t (*config_readb)(QVirtioDevice *d, uint64_t addr);
48     uint16_t (*config_readw)(QVirtioDevice *d, uint64_t addr);
49     uint32_t (*config_readl)(QVirtioDevice *d, uint64_t addr);
50     uint64_t (*config_readq)(QVirtioDevice *d, uint64_t addr);
51 
52     /* Get features of the device */
53     uint32_t (*get_features)(QVirtioDevice *d);
54 
55     /* Set features of the device */
56     void (*set_features)(QVirtioDevice *d, uint32_t features);
57 
58     /* Get features of the guest */
59     uint32_t (*get_guest_features)(QVirtioDevice *d);
60 
61     /* Get status of the device */
62     uint8_t (*get_status)(QVirtioDevice *d);
63 
64     /* Set status of the device  */
65     void (*set_status)(QVirtioDevice *d, uint8_t status);
66 
67     /* Get the queue ISR status of the device */
68     bool (*get_queue_isr_status)(QVirtioDevice *d, QVirtQueue *vq);
69 
70     /* Get the configuration ISR status of the device */
71     bool (*get_config_isr_status)(QVirtioDevice *d);
72 
73     /* Select a queue to work on */
74     void (*queue_select)(QVirtioDevice *d, uint16_t index);
75 
76     /* Get the size of the selected queue */
77     uint16_t (*get_queue_size)(QVirtioDevice *d);
78 
79     /* Set the address of the selected queue */
80     void (*set_queue_address)(QVirtioDevice *d, uint32_t pfn);
81 
82     /* Setup the virtqueue specified by index */
83     QVirtQueue *(*virtqueue_setup)(QVirtioDevice *d, QGuestAllocator *alloc,
84                                                                 uint16_t index);
85 
86     /* Free virtqueue resources */
87     void (*virtqueue_cleanup)(QVirtQueue *vq, QGuestAllocator *alloc);
88 
89     /* Notify changes in virtqueue */
90     void (*virtqueue_kick)(QVirtioDevice *d, QVirtQueue *vq);
91 };
92 
qvirtio_is_big_endian(QVirtioDevice * d)93 static inline bool qvirtio_is_big_endian(QVirtioDevice *d)
94 {
95     /* FIXME: virtio 1.0 is always little-endian */
96     return qtest_big_endian(global_qtest);
97 }
98 
qvring_size(uint32_t num,uint32_t align)99 static inline uint32_t qvring_size(uint32_t num, uint32_t align)
100 {
101     return ((sizeof(struct vring_desc) * num + sizeof(uint16_t) * (3 + num)
102         + align - 1) & ~(align - 1))
103         + sizeof(uint16_t) * 3 + sizeof(struct vring_used_elem) * num;
104 }
105 
106 uint8_t qvirtio_config_readb(QVirtioDevice *d, uint64_t addr);
107 uint16_t qvirtio_config_readw(QVirtioDevice *d, uint64_t addr);
108 uint32_t qvirtio_config_readl(QVirtioDevice *d, uint64_t addr);
109 uint64_t qvirtio_config_readq(QVirtioDevice *d, uint64_t addr);
110 uint32_t qvirtio_get_features(QVirtioDevice *d);
111 void qvirtio_set_features(QVirtioDevice *d, uint32_t features);
112 
113 void qvirtio_reset(QVirtioDevice *d);
114 void qvirtio_set_acknowledge(QVirtioDevice *d);
115 void qvirtio_set_driver(QVirtioDevice *d);
116 void qvirtio_set_driver_ok(QVirtioDevice *d);
117 
118 void qvirtio_wait_queue_isr(QVirtioDevice *d,
119                             QVirtQueue *vq, gint64 timeout_us);
120 uint8_t qvirtio_wait_status_byte_no_isr(QVirtioDevice *d,
121                                         QVirtQueue *vq,
122                                         uint64_t addr,
123                                         gint64 timeout_us);
124 void qvirtio_wait_used_elem(QVirtioDevice *d,
125                             QVirtQueue *vq,
126                             uint32_t desc_idx,
127                             uint32_t *len,
128                             gint64 timeout_us);
129 void qvirtio_wait_config_isr(QVirtioDevice *d, gint64 timeout_us);
130 QVirtQueue *qvirtqueue_setup(QVirtioDevice *d,
131                              QGuestAllocator *alloc, uint16_t index);
132 void qvirtqueue_cleanup(const QVirtioBus *bus, QVirtQueue *vq,
133                         QGuestAllocator *alloc);
134 
135 void qvring_init(const QGuestAllocator *alloc, QVirtQueue *vq, uint64_t addr);
136 QVRingIndirectDesc *qvring_indirect_desc_setup(QVirtioDevice *d,
137                                         QGuestAllocator *alloc, uint16_t elem);
138 void qvring_indirect_desc_add(QVRingIndirectDesc *indirect, uint64_t data,
139                                                     uint32_t len, bool write);
140 uint32_t qvirtqueue_add(QVirtQueue *vq, uint64_t data, uint32_t len, bool write,
141                                                                     bool next);
142 uint32_t qvirtqueue_add_indirect(QVirtQueue *vq, QVRingIndirectDesc *indirect);
143 void qvirtqueue_kick(QVirtioDevice *d, QVirtQueue *vq, uint32_t free_head);
144 bool qvirtqueue_get_buf(QVirtQueue *vq, uint32_t *desc_idx, uint32_t *len);
145 
146 void qvirtqueue_set_used_event(QVirtQueue *vq, uint16_t idx);
147 
148 const char *qvirtio_get_dev_type(void);
149 
150 #endif
151