lguest_hcall.h 2.4 KB

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  1. /* Architecture specific portion of the lguest hypercalls */
  2. #ifndef ASM_X86__LGUEST_HCALL_H
  3. #define ASM_X86__LGUEST_HCALL_H
  4. #define LHCALL_FLUSH_ASYNC 0
  5. #define LHCALL_LGUEST_INIT 1
  6. #define LHCALL_SHUTDOWN 2
  7. #define LHCALL_LOAD_GDT 3
  8. #define LHCALL_NEW_PGTABLE 4
  9. #define LHCALL_FLUSH_TLB 5
  10. #define LHCALL_LOAD_IDT_ENTRY 6
  11. #define LHCALL_SET_STACK 7
  12. #define LHCALL_TS 8
  13. #define LHCALL_SET_CLOCKEVENT 9
  14. #define LHCALL_HALT 10
  15. #define LHCALL_SET_PTE 14
  16. #define LHCALL_SET_PMD 15
  17. #define LHCALL_LOAD_TLS 16
  18. #define LHCALL_NOTIFY 17
  19. #define LGUEST_TRAP_ENTRY 0x1F
  20. /* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
  21. #define LGUEST_SHUTDOWN_POWEROFF 1
  22. #define LGUEST_SHUTDOWN_RESTART 2
  23. #ifndef __ASSEMBLY__
  24. #include <asm/hw_irq.h>
  25. /*G:031 But first, how does our Guest contact the Host to ask for privileged
  26. * operations? There are two ways: the direct way is to make a "hypercall",
  27. * to make requests of the Host Itself.
  28. *
  29. * Our hypercall mechanism uses the highest unused trap code (traps 32 and
  30. * above are used by real hardware interrupts). Fifteen hypercalls are
  31. * available: the hypercall number is put in the %eax register, and the
  32. * arguments (when required) are placed in %edx, %ebx and %ecx. If a return
  33. * value makes sense, it's returned in %eax.
  34. *
  35. * Grossly invalid calls result in Sudden Death at the hands of the vengeful
  36. * Host, rather than returning failure. This reflects Winston Churchill's
  37. * definition of a gentleman: "someone who is only rude intentionally". */
  38. static inline unsigned long
  39. hcall(unsigned long call,
  40. unsigned long arg1, unsigned long arg2, unsigned long arg3)
  41. {
  42. /* "int" is the Intel instruction to trigger a trap. */
  43. asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
  44. /* The call in %eax (aka "a") might be overwritten */
  45. : "=a"(call)
  46. /* The arguments are in %eax, %edx, %ebx & %ecx */
  47. : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
  48. /* "memory" means this might write somewhere in memory.
  49. * This isn't true for all calls, but it's safe to tell
  50. * gcc that it might happen so it doesn't get clever. */
  51. : "memory");
  52. return call;
  53. }
  54. /*:*/
  55. /* Can't use our min() macro here: needs to be a constant */
  56. #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
  57. #define LHCALL_RING_SIZE 64
  58. struct hcall_args {
  59. /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */
  60. unsigned long arg0, arg2, arg3, arg1;
  61. };
  62. #endif /* !__ASSEMBLY__ */
  63. #endif /* ASM_X86__LGUEST_HCALL_H */