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1 | #ifndef _ASM_LGUEST_USER |
2 | #define _ASM_LGUEST_USER | |
3 | /* Everything the "lguest" userspace program needs to know. */ | |
4 | /* They can register up to 32 arrays of lguest_dma. */ | |
5 | #define LGUEST_MAX_DMA 32 | |
6 | /* At most we can dma 16 lguest_dma in one op. */ | |
7 | #define LGUEST_MAX_DMA_SECTIONS 16 | |
8 | ||
9 | /* How many devices? Assume each one wants up to two dma arrays per device. */ | |
10 | #define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2) | |
11 | ||
e2c97843 RR |
12 | /*D:200 |
13 | * Lguest I/O | |
14 | * | |
15 | * The lguest I/O mechanism is the only way Guests can talk to devices. There | |
16 | * are two hypercalls involved: SEND_DMA for output and BIND_DMA for input. In | |
17 | * each case, "struct lguest_dma" describes the buffer: this contains 16 | |
18 | * addr/len pairs, and if there are fewer buffer elements the len array is | |
19 | * terminated with a 0. | |
20 | * | |
21 | * I/O is organized by keys: BIND_DMA attaches buffers to a particular key, and | |
22 | * SEND_DMA transfers to buffers bound to particular key. By convention, keys | |
23 | * correspond to a physical address within the device's page. This means that | |
24 | * devices will never accidentally end up with the same keys, and allows the | |
25 | * Host use The Futex Trick (as we'll see later in our journey). | |
26 | * | |
27 | * SEND_DMA simply indicates a key to send to, and the physical address of the | |
28 | * "struct lguest_dma" to send. The Host will write the number of bytes | |
29 | * transferred into the "struct lguest_dma"'s used_len member. | |
30 | * | |
31 | * BIND_DMA indicates a key to bind to, a pointer to an array of "struct | |
32 | * lguest_dma"s ready for receiving, the size of that array, and an interrupt | |
33 | * to trigger when data is received. The Host will only allow transfers into | |
34 | * buffers with a used_len of zero: it then sets used_len to the number of | |
35 | * bytes transferred and triggers the interrupt for the Guest to process the | |
36 | * new input. */ | |
d7e28ffe RR |
37 | struct lguest_dma |
38 | { | |
e2c97843 | 39 | /* 0 if free to be used, filled by the Host. */ |
d7e28ffe RR |
40 | u32 used_len; |
41 | unsigned long addr[LGUEST_MAX_DMA_SECTIONS]; | |
42 | u16 len[LGUEST_MAX_DMA_SECTIONS]; | |
43 | }; | |
e2c97843 | 44 | /*:*/ |
d7e28ffe | 45 | |
e2c97843 RR |
46 | /*D:460 This is the layout of a block device memory page. The Launcher sets up |
47 | * the num_sectors initially to tell the Guest the size of the disk. The Guest | |
48 | * puts the type, sector and length of the request in the first three fields, | |
49 | * then DMAs to the Host. The Host processes the request, sets up the result, | |
50 | * then DMAs back to the Guest. */ | |
d7e28ffe RR |
51 | struct lguest_block_page |
52 | { | |
53 | /* 0 is a read, 1 is a write. */ | |
54 | int type; | |
55 | u32 sector; /* Offset in device = sector * 512. */ | |
56 | u32 bytes; /* Length expected to be read/written in bytes */ | |
57 | /* 0 = pending, 1 = done, 2 = done, error */ | |
58 | int result; | |
59 | u32 num_sectors; /* Disk length = num_sectors * 512 */ | |
60 | }; | |
61 | ||
e2c97843 RR |
62 | /*D:520 The network device is basically a memory page where all the Guests on |
63 | * the network publish their MAC (ethernet) addresses: it's an array of "struct | |
64 | * lguest_net": */ | |
d7e28ffe RR |
65 | struct lguest_net |
66 | { | |
67 | /* Simply the mac address (with multicast bit meaning promisc). */ | |
68 | unsigned char mac[6]; | |
69 | }; | |
e2c97843 | 70 | /*:*/ |
d7e28ffe RR |
71 | |
72 | /* Where the Host expects the Guest to SEND_DMA console output to. */ | |
73 | #define LGUEST_CONSOLE_DMA_KEY 0 | |
74 | ||
e2c97843 RR |
75 | /*D:010 |
76 | * Drivers | |
77 | * | |
78 | * The Guest needs devices to do anything useful. Since we don't let it touch | |
79 | * real devices (think of the damage it could do!) we provide virtual devices. | |
80 | * We could emulate a PCI bus with various devices on it, but that is a fairly | |
81 | * complex burden for the Host and suboptimal for the Guest, so we have our own | |
82 | * "lguest" bus and simple drivers. | |
83 | * | |
84 | * Devices are described by an array of LGUEST_MAX_DEVICES of these structs, | |
85 | * placed by the Launcher just above the top of physical memory: | |
86 | */ | |
d7e28ffe | 87 | struct lguest_device_desc { |
e2c97843 | 88 | /* The device type: console, network, disk etc. */ |
d7e28ffe RR |
89 | u16 type; |
90 | #define LGUEST_DEVICE_T_CONSOLE 1 | |
91 | #define LGUEST_DEVICE_T_NET 2 | |
92 | #define LGUEST_DEVICE_T_BLOCK 3 | |
93 | ||
e2c97843 RR |
94 | /* The specific features of this device: these depends on device type |
95 | * except for LGUEST_DEVICE_F_RANDOMNESS. */ | |
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96 | u16 features; |
97 | #define LGUEST_NET_F_NOCSUM 0x4000 /* Don't bother checksumming */ | |
98 | #define LGUEST_DEVICE_F_RANDOMNESS 0x8000 /* IRQ is fairly random */ | |
99 | ||
e2c97843 RR |
100 | /* This is how the Guest reports status of the device: the Host can set |
101 | * LGUEST_DEVICE_S_REMOVED to indicate removal, but the rest are only | |
102 | * ever manipulated by the Guest, and only ever set. */ | |
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103 | u16 status; |
104 | /* 256 and above are device specific. */ | |
105 | #define LGUEST_DEVICE_S_ACKNOWLEDGE 1 /* We have seen device. */ | |
106 | #define LGUEST_DEVICE_S_DRIVER 2 /* We have found a driver */ | |
107 | #define LGUEST_DEVICE_S_DRIVER_OK 4 /* Driver says OK! */ | |
108 | #define LGUEST_DEVICE_S_REMOVED 8 /* Device has gone away. */ | |
109 | #define LGUEST_DEVICE_S_REMOVED_ACK 16 /* Driver has been told. */ | |
110 | #define LGUEST_DEVICE_S_FAILED 128 /* Something actually failed */ | |
111 | ||
e2c97843 RR |
112 | /* Each device exists somewhere in Guest physical memory, over some |
113 | * number of pages. */ | |
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114 | u16 num_pages; |
115 | u32 pfn; | |
116 | }; | |
e2c97843 | 117 | /*:*/ |
d7e28ffe RR |
118 | |
119 | /* Write command first word is a request. */ | |
120 | enum lguest_req | |
121 | { | |
122 | LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */ | |
123 | LHREQ_GETDMA, /* + addr (returns &lguest_dma, irq in ->used_len) */ | |
124 | LHREQ_IRQ, /* + irq */ | |
125 | LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */ | |
126 | }; | |
127 | #endif /* _ASM_LGUEST_USER */ |