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_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
  22 /*G:031 First, how does our Guest contact the Host to ask for privileged
  23  * operations?  There are two ways: the direct way is to make a "hypercall",
  24  * to make requests of the Host Itself.
  25  *
  26  * Our hypercall mechanism uses the highest unused trap code (traps 32 and
  27  * above are used by real hardware interrupts).  Seventeen hypercalls are
  28  * available: the hypercall number is put in the %eax register, and the
  29  * arguments (when required) are placed in %edx, %ebx and %ecx.  If a return
  30  * value makes sense, it's returned in %eax.
  31  *
  32  * Grossly invalid calls result in Sudden Death at the hands of the vengeful
  33  * Host, rather than returning failure.  This reflects Winston Churchill's
  34  * definition of a gentleman: "someone who is only rude intentionally". */
  35 #define LGUEST_TRAP_ENTRY 0x1F
  36
  37 static inline unsigned long
  38 hcall(unsigned long call,
  39       unsigned long arg1, unsigned long arg2, unsigned long arg3)
  40 {
  41         /* "int" is the Intel instruction to trigger a trap. */
  42         asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
  43                        /* The call is in %eax (aka "a"), and can be replaced */
  44                      : "=a"(call)
  45                        /* The other arguments are in %eax, %edx, %ebx & %ecx */
  46                      : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
  47                        /* "memory" means this might write somewhere in memory.
  48                         * This isn't true for all calls, but it's safe to tell
  49                         * gcc that it might happen so it doesn't get clever. */
  50                      : "memory");
  51         return call;
  52 }
  53 /*:*/
  54
  55 void async_hcall(unsigned long call,
  56                  unsigned long arg1, unsigned long arg2, unsigned long arg3);
  57
  58 /* Can't use our min() macro here: needs to be a constant */
  59 #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
  60
  61 #define LHCALL_RING_SIZE 64
  62 struct hcall_ring
  63 {
  64         u32 eax, edx, ebx, ecx;
  65 };
  66
  67 #endif  /* _I386_LGUEST_HCALL_H */