include/asm-x86/lguest_hcall.h

   1 /* Architecture specific portion of the lguest hypercalls */
   2 #ifndef _X86_LGUEST_HCALL_H
   3 #define _X86_LGUEST_HCALL_H
   4
   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_SET_PTE          14
  17 #define LHCALL_SET_PMD          15
  18 #define LHCALL_LOAD_TLS         16
  19 #define LHCALL_NOTIFY           17
  20
  21 #define LGUEST_TRAP_ENTRY 0x1F
  22
  23 #ifndef __ASSEMBLY__
  24 #include <asm/hw_irq.h>
  25
  26 /*G:031 First, how does our Guest contact the Host to ask for privileged
  27  * operations?  There are two ways: the direct way is to make a "hypercall",
  28  * to make requests of the Host Itself.
  29  *
  30  * Our hypercall mechanism uses the highest unused trap code (traps 32 and
  31  * above are used by real hardware interrupts).  Fifteen hypercalls are
  32  * available: the hypercall number is put in the %eax register, and the
  33  * arguments (when required) are placed in %edx, %ebx and %ecx.  If a return
  34  * value makes sense, it's returned in %eax.
  35  *
  36  * Grossly invalid calls result in Sudden Death at the hands of the vengeful
  37  * Host, rather than returning failure.  This reflects Winston Churchill's
  38  * definition of a gentleman: "someone who is only rude intentionally". */
  39 static inline unsigned long
  40 hcall(unsigned long call,
  41       unsigned long arg1, unsigned long arg2, unsigned long arg3)
  42 {
  43         /* "int" is the Intel instruction to trigger a trap. */
  44         asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
  45                        /* The call in %eax (aka "a") might be overwritten */
  46                      : "=a"(call)
  47                        /* The arguments are in %eax, %edx, %ebx & %ecx */
  48                      : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
  49                        /* "memory" means this might write somewhere in memory.
  50                         * This isn't true for all calls, but it's safe to tell
  51                         * gcc that it might happen so it doesn't get clever. */
  52                      : "memory");
  53         return call;
  54 }
  55 /*:*/
  56
  57 /* Can't use our min() macro here: needs to be a constant */
  58 #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
  59
  60 #define LHCALL_RING_SIZE 64
  61 struct hcall_args
  62 {
  63         /* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */
  64         unsigned long arg0, arg2, arg3, arg1;
  65 };
  66
  67 #endif /* !__ASSEMBLY__ */
  68 #endif  /* _I386_LGUEST_HCALL_H */