include/linux/lguest.h

   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         /*
  24          * 512 == enabled (same as eflags in normal hardware).  The Guest
  25          * changes interrupts so often that a hypercall is too slow.
  26          */
  27         unsigned int irq_enabled;
  28         /* Fine-grained interrupt disabling by the Guest */
  29         DECLARE_BITMAP(blocked_interrupts, LGUEST_IRQS);
  30
  31         /*
  32          * The Host writes the virtual address of the last page fault here,
  33          * which saves the Guest a hypercall.  CR2 is the native register where
  34          * this address would normally be found.
  35          */
  36         unsigned long cr2;
  37
  38         /* Wallclock time set by the Host. */
  39         struct timespec time;
  40
  41         /*
  42          * Interrupt pending set by the Host.  The Guest should do a hypercall
  43          * if it re-enables interrupts and sees this set (to X86_EFLAGS_IF).
  44          */
  45         int irq_pending;
  46
  47         /*
  48          * Async hypercall ring.  Instead of directly making hypercalls, we can
  49          * place them in here for processing the next time the Host wants.
  50          * This batching can be quite efficient.
  51          */
  52
  53         /* 0xFF == done (set by Host), 0 == pending (set by Guest). */
  54         u8 hcall_status[LHCALL_RING_SIZE];
  55         /* The actual registers for the hypercalls. */
  56         struct hcall_args hcalls[LHCALL_RING_SIZE];
  57
  58 /* Fields initialized by the Host at boot: */
  59         /* Memory not to try to access */
  60         unsigned long reserve_mem;
  61         /* KHz for the TSC clock. */
  62         u32 tsc_khz;
  63         /* Page where the top-level pagetable is */
  64         unsigned long pgdir;
  65
  66 /* Fields initialized by the Guest at boot: */
  67         /* Instruction range to suppress interrupts even if enabled */
  68         unsigned long noirq_start, noirq_end;
  69         /* Address above which page tables are all identical. */
  70         unsigned long kernel_address;
  71         /* The vector to try to use for system calls (0x40 or 0x80). */
  72         unsigned int syscall_vec;
  73 };
  74 extern struct lguest_data lguest_data;
  75 #endif /* __ASSEMBLY__ */
  76 #endif  /* _LINUX_LGUEST_H */