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-rw-r--r--include/linux/lguest_launcher.h36
1 files changed, 1 insertions, 35 deletions
diff --git a/include/linux/lguest_launcher.h b/include/linux/lguest_launcher.h
index b6603f3fbff8..5ec04a225e4f 100644
--- a/include/linux/lguest_launcher.h
+++ b/include/linux/lguest_launcher.h
@@ -10,40 +10,6 @@
10/* How many devices? Assume each one wants up to two dma arrays per device. */ 10/* How many devices? Assume each one wants up to two dma arrays per device. */
11#define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2) 11#define LGUEST_MAX_DEVICES (LGUEST_MAX_DMA/2)
12 12
13/*D:200
14 * Lguest I/O
15 *
16 * The lguest I/O mechanism is the only way Guests can talk to devices. There
17 * are two hypercalls involved: SEND_DMA for output and BIND_DMA for input. In
18 * each case, "struct lguest_dma" describes the buffer: this contains 16
19 * addr/len pairs, and if there are fewer buffer elements the len array is
20 * terminated with a 0.
21 *
22 * I/O is organized by keys: BIND_DMA attaches buffers to a particular key, and
23 * SEND_DMA transfers to buffers bound to particular key. By convention, keys
24 * correspond to a physical address within the device's page. This means that
25 * devices will never accidentally end up with the same keys, and allows the
26 * Host use The Futex Trick (as we'll see later in our journey).
27 *
28 * SEND_DMA simply indicates a key to send to, and the physical address of the
29 * "struct lguest_dma" to send. The Host will write the number of bytes
30 * transferred into the "struct lguest_dma"'s used_len member.
31 *
32 * BIND_DMA indicates a key to bind to, a pointer to an array of "struct
33 * lguest_dma"s ready for receiving, the size of that array, and an interrupt
34 * to trigger when data is received. The Host will only allow transfers into
35 * buffers with a used_len of zero: it then sets used_len to the number of
36 * bytes transferred and triggers the interrupt for the Guest to process the
37 * new input. */
38struct lguest_dma
39{
40 /* 0 if free to be used, filled by the Host. */
41 __u32 used_len;
42 __u16 len[LGUEST_MAX_DMA_SECTIONS];
43 unsigned long addr[LGUEST_MAX_DMA_SECTIONS];
44};
45/*:*/
46
47/* Where the Host expects the Guest to SEND_DMA console output to. */ 13/* Where the Host expects the Guest to SEND_DMA console output to. */
48#define LGUEST_CONSOLE_DMA_KEY 0 14#define LGUEST_CONSOLE_DMA_KEY 0
49 15
@@ -95,7 +61,7 @@ struct lguest_device_desc {
95enum lguest_req 61enum lguest_req
96{ 62{
97 LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */ 63 LHREQ_INITIALIZE, /* + pfnlimit, pgdir, start, pageoffset */
98 LHREQ_GETDMA, /* + addr (returns &lguest_dma, irq in ->used_len) */ 64 LHREQ_GETDMA, /* No longer used */
99 LHREQ_IRQ, /* + irq */ 65 LHREQ_IRQ, /* + irq */
100 LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */ 66 LHREQ_BREAK, /* + on/off flag (on blocks until someone does off) */
101}; 67};