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Rusty Russell07ad1572007-07-19 01:49:22 -07001/* Things the lguest guest needs to know. Note: like all lguest interfaces,
2 * this is subject to wild and random change between versions. */
3#ifndef _ASM_LGUEST_H
4#define _ASM_LGUEST_H
5
Rusty Russell07ad1572007-07-19 01:49:22 -07006#ifndef __ASSEMBLY__
7#include <asm/irq.h>
8
9#define LHCALL_FLUSH_ASYNC 0
10#define LHCALL_LGUEST_INIT 1
11#define LHCALL_CRASH 2
12#define LHCALL_LOAD_GDT 3
13#define LHCALL_NEW_PGTABLE 4
14#define LHCALL_FLUSH_TLB 5
15#define LHCALL_LOAD_IDT_ENTRY 6
16#define LHCALL_SET_STACK 7
17#define LHCALL_TS 8
Rusty Russelld7e28ff2007-07-19 01:49:23 -070018#define LHCALL_SET_CLOCKEVENT 9
Rusty Russell07ad1572007-07-19 01:49:22 -070019#define LHCALL_HALT 10
Rusty Russell07ad1572007-07-19 01:49:22 -070020#define LHCALL_BIND_DMA 12
21#define LHCALL_SEND_DMA 13
22#define LHCALL_SET_PTE 14
23#define LHCALL_SET_PMD 15
24#define LHCALL_LOAD_TLS 16
25
Rusty Russelld7e28ff2007-07-19 01:49:23 -070026#define LG_CLOCK_MIN_DELTA 100UL
27#define LG_CLOCK_MAX_DELTA ULONG_MAX
28
Rusty Russellb2b47c22007-07-26 10:41:02 -070029/*G:031 First, how does our Guest contact the Host to ask for privileged
30 * operations? There are two ways: the direct way is to make a "hypercall",
31 * to make requests of the Host Itself.
32 *
33 * Our hypercall mechanism uses the highest unused trap code (traps 32 and
34 * above are used by real hardware interrupts). Seventeen hypercalls are
35 * available: the hypercall number is put in the %eax register, and the
36 * arguments (when required) are placed in %edx, %ebx and %ecx. If a return
37 * value makes sense, it's returned in %eax.
38 *
39 * Grossly invalid calls result in Sudden Death at the hands of the vengeful
40 * Host, rather than returning failure. This reflects Winston Churchill's
41 * definition of a gentleman: "someone who is only rude intentionally". */
Rusty Russell07ad1572007-07-19 01:49:22 -070042#define LGUEST_TRAP_ENTRY 0x1F
43
44static inline unsigned long
45hcall(unsigned long call,
46 unsigned long arg1, unsigned long arg2, unsigned long arg3)
47{
Rusty Russellb2b47c22007-07-26 10:41:02 -070048 /* "int" is the Intel instruction to trigger a trap. */
Rusty Russell07ad1572007-07-19 01:49:22 -070049 asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
Rusty Russellb2b47c22007-07-26 10:41:02 -070050 /* The call is in %eax (aka "a"), and can be replaced */
Rusty Russell07ad1572007-07-19 01:49:22 -070051 : "=a"(call)
Rusty Russellb2b47c22007-07-26 10:41:02 -070052 /* The other arguments are in %eax, %edx, %ebx & %ecx */
Rusty Russell07ad1572007-07-19 01:49:22 -070053 : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
Rusty Russellb2b47c22007-07-26 10:41:02 -070054 /* "memory" means this might write somewhere in memory.
55 * This isn't true for all calls, but it's safe to tell
56 * gcc that it might happen so it doesn't get clever. */
Rusty Russell07ad1572007-07-19 01:49:22 -070057 : "memory");
58 return call;
59}
Rusty Russellb2b47c22007-07-26 10:41:02 -070060/*:*/
Rusty Russell07ad1572007-07-19 01:49:22 -070061
62void async_hcall(unsigned long call,
63 unsigned long arg1, unsigned long arg2, unsigned long arg3);
64
65/* Can't use our min() macro here: needs to be a constant */
66#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
67
68#define LHCALL_RING_SIZE 64
69struct hcall_ring
70{
71 u32 eax, edx, ebx, ecx;
72};
73
Rusty Russellb2b47c22007-07-26 10:41:02 -070074/*G:032 The second method of communicating with the Host is to via "struct
75 * lguest_data". The Guest's very first hypercall is to tell the Host where
76 * this is, and then the Guest and Host both publish information in it. :*/
Rusty Russell07ad1572007-07-19 01:49:22 -070077struct lguest_data
78{
Rusty Russellb2b47c22007-07-26 10:41:02 -070079 /* 512 == enabled (same as eflags in normal hardware). The Guest
80 * changes interrupts so often that a hypercall is too slow. */
Rusty Russell07ad1572007-07-19 01:49:22 -070081 unsigned int irq_enabled;
Rusty Russellb2b47c22007-07-26 10:41:02 -070082 /* Fine-grained interrupt disabling by the Guest */
Rusty Russell07ad1572007-07-19 01:49:22 -070083 DECLARE_BITMAP(blocked_interrupts, LGUEST_IRQS);
84
Rusty Russellb2b47c22007-07-26 10:41:02 -070085 /* The Host writes the virtual address of the last page fault here,
86 * which saves the Guest a hypercall. CR2 is the native register where
87 * this address would normally be found. */
Rusty Russell07ad1572007-07-19 01:49:22 -070088 unsigned long cr2;
89
Rusty Russell6c8dca52007-07-27 13:42:52 +100090 /* Wallclock time set by the Host. */
91 struct timespec time;
92
Rusty Russellb2b47c22007-07-26 10:41:02 -070093 /* Async hypercall ring. Instead of directly making hypercalls, we can
94 * place them in here for processing the next time the Host wants.
95 * This batching can be quite efficient. */
96
97 /* 0xFF == done (set by Host), 0 == pending (set by Guest). */
Rusty Russell07ad1572007-07-19 01:49:22 -070098 u8 hcall_status[LHCALL_RING_SIZE];
Rusty Russellb2b47c22007-07-26 10:41:02 -070099 /* The actual registers for the hypercalls. */
Rusty Russell07ad1572007-07-19 01:49:22 -0700100 struct hcall_ring hcalls[LHCALL_RING_SIZE];
101
Rusty Russellb2b47c22007-07-26 10:41:02 -0700102/* Fields initialized by the Host at boot: */
Rusty Russell07ad1572007-07-19 01:49:22 -0700103 /* Memory not to try to access */
104 unsigned long reserve_mem;
Rusty Russellb2b47c22007-07-26 10:41:02 -0700105 /* ID of this Guest (used by network driver to set ethernet address) */
Rusty Russell07ad1572007-07-19 01:49:22 -0700106 u16 guestid;
Rusty Russelld7e28ff2007-07-19 01:49:23 -0700107 /* KHz for the TSC clock. */
108 u32 tsc_khz;
Rusty Russell07ad1572007-07-19 01:49:22 -0700109
Rusty Russellb2b47c22007-07-26 10:41:02 -0700110/* Fields initialized by the Guest at boot: */
Rusty Russell07ad1572007-07-19 01:49:22 -0700111 /* Instruction range to suppress interrupts even if enabled */
112 unsigned long noirq_start, noirq_end;
113};
114extern struct lguest_data lguest_data;
115#endif /* __ASSEMBLY__ */
116#endif /* _ASM_LGUEST_H */