1 /*
2  * Things the lguest guest needs to know.  Note: like all lguest interfaces,
3  * this is subject to wild and random change between versions.
4  */
5 #ifndef _LINUX_LGUEST_H
6 #define _LINUX_LGUEST_H
7 
8 #ifndef __ASSEMBLY__
9 #include <linux/time.h>
10 #include <asm/irq.h>
11 #include <asm/lguest_hcall.h>
12 
13 #define LG_CLOCK_MIN_DELTA	100UL
14 #define LG_CLOCK_MAX_DELTA	ULONG_MAX
15 
16 /*G:031
17  * The second method of communicating with the Host is to via "struct
18  * lguest_data".  Once the Guest's initialization hypercall tells the Host where
19  * this is, the Guest and Host both publish information in it.
20 :*/
21 struct lguest_data {
22 	/*
23 	 * 512 == enabled (same as eflags in normal hardware).  The Guest
24 	 * changes interrupts so often that a hypercall is too slow.
25 	 */
26 	unsigned int irq_enabled;
27 	/* Fine-grained interrupt disabling by the Guest */
28 	DECLARE_BITMAP(blocked_interrupts, LGUEST_IRQS);
29 
30 	/*
31 	 * The Host writes the virtual address of the last page fault here,
32 	 * which saves the Guest a hypercall.  CR2 is the native register where
33 	 * this address would normally be found.
34 	 */
35 	unsigned long cr2;
36 
37 	/* Wallclock time set by the Host. */
38 	struct timespec time;
39 
40 	/*
41 	 * Interrupt pending set by the Host.  The Guest should do a hypercall
42 	 * if it re-enables interrupts and sees this set (to X86_EFLAGS_IF).
43 	 */
44 	int irq_pending;
45 
46 	/*
47 	 * Async hypercall ring.  Instead of directly making hypercalls, we can
48 	 * place them in here for processing the next time the Host wants.
49 	 * This batching can be quite efficient.
50 	 */
51 
52 	/* 0xFF == done (set by Host), 0 == pending (set by Guest). */
53 	u8 hcall_status[LHCALL_RING_SIZE];
54 	/* The actual registers for the hypercalls. */
55 	struct hcall_args hcalls[LHCALL_RING_SIZE];
56 
57 /* Fields initialized by the Host at boot: */
58 	/* Memory not to try to access */
59 	unsigned long reserve_mem;
60 	/* KHz for the TSC clock. */
61 	u32 tsc_khz;
62 	/* Page where the top-level pagetable is */
63 	unsigned long pgdir;
64 
65 /* Fields initialized by the Guest at boot: */
66 	/* Instruction range to suppress interrupts even if enabled */
67 	unsigned long noirq_start, noirq_end;
68 	/* Address above which page tables are all identical. */
69 	unsigned long kernel_address;
70 	/* The vector to try to use for system calls (0x40 or 0x80). */
71 	unsigned int syscall_vec;
72 };
73 extern struct lguest_data lguest_data;
74 #endif /* __ASSEMBLY__ */
75 #endif	/* _LINUX_LGUEST_H */
76