lguest_hcall.h 2.4 KB

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  1. /* Architecture specific portion of the lguest hypercalls */
  2. #ifndef _X86_LGUEST_HCALL_H
  3. #define _X86_LGUEST_HCALL_H
  4. #include <asm/hw_irq.h>
  5. #define LHCALL_FLUSH_ASYNC 0
  6. #define LHCALL_LGUEST_INIT 1
  7. #define LHCALL_CRASH 2
  8. #define LHCALL_LOAD_GDT 3
  9. #define LHCALL_NEW_PGTABLE 4
  10. #define LHCALL_FLUSH_TLB 5
  11. #define LHCALL_LOAD_IDT_ENTRY 6
  12. #define LHCALL_SET_STACK 7
  13. #define LHCALL_TS 8
  14. #define LHCALL_SET_CLOCKEVENT 9
  15. #define LHCALL_HALT 10
  16. #define LHCALL_BIND_DMA 12
  17. #define LHCALL_SEND_DMA 13
  18. #define LHCALL_SET_PTE 14
  19. #define LHCALL_SET_PMD 15
  20. #define LHCALL_LOAD_TLS 16
  21. /*G:031 First, how does our Guest contact the Host to ask for privileged
  22. * operations? There are two ways: the direct way is to make a "hypercall",
  23. * to make requests of the Host Itself.
  24. *
  25. * Our hypercall mechanism uses the highest unused trap code (traps 32 and
  26. * above are used by real hardware interrupts). Seventeen hypercalls are
  27. * available: the hypercall number is put in the %eax register, and the
  28. * arguments (when required) are placed in %edx, %ebx and %ecx. If a return
  29. * value makes sense, it's returned in %eax.
  30. *
  31. * Grossly invalid calls result in Sudden Death at the hands of the vengeful
  32. * Host, rather than returning failure. This reflects Winston Churchill's
  33. * definition of a gentleman: "someone who is only rude intentionally". */
  34. #define LGUEST_TRAP_ENTRY 0x1F
  35. static inline unsigned long
  36. hcall(unsigned long call,
  37. unsigned long arg1, unsigned long arg2, unsigned long arg3)
  38. {
  39. /* "int" is the Intel instruction to trigger a trap. */
  40. asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
  41. /* The call is in %eax (aka "a"), and can be replaced */
  42. : "=a"(call)
  43. /* The other arguments are in %eax, %edx, %ebx & %ecx */
  44. : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
  45. /* "memory" means this might write somewhere in memory.
  46. * This isn't true for all calls, but it's safe to tell
  47. * gcc that it might happen so it doesn't get clever. */
  48. : "memory");
  49. return call;
  50. }
  51. /*:*/
  52. void async_hcall(unsigned long call,
  53. unsigned long arg1, unsigned long arg2, unsigned long arg3);
  54. /* Can't use our min() macro here: needs to be a constant */
  55. #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
  56. #define LHCALL_RING_SIZE 64
  57. struct hcall_args
  58. {
  59. /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */
  60. unsigned long arg0, arg2, arg3, arg1;
  61. };
  62. #endif /* _I386_LGUEST_HCALL_H */