arch/x86/include/asm/lguest_hcall.h

   1 /* Architecture specific portion of the lguest hypercalls */
   2 #ifndef _ASM_X86_LGUEST_HCALL_H
   3 #define _ASM_X86_LGUEST_HCALL_H
   4
   5 #define LHCALL_FLUSH_ASYNC      0
   6 #define LHCALL_LGUEST_INIT      1
   7 #define LHCALL_SHUTDOWN         2
   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_PMD          13
  16 #define LHCALL_SET_PTE          14
  17 #define LHCALL_SET_PGD          15
  18 #define LHCALL_LOAD_TLS         16
  19 #define LHCALL_NOTIFY           17
  20 #define LHCALL_LOAD_GDT_ENTRY   18
  21 #define LHCALL_SEND_INTERRUPTS  19
  22
  23 #define LGUEST_TRAP_ENTRY 0x1F
  24
  25 /* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
  26 #define LGUEST_SHUTDOWN_POWEROFF        1
  27 #define LGUEST_SHUTDOWN_RESTART         2
  28
  29 #ifndef __ASSEMBLY__
  30 #include <asm/hw_irq.h>
  31
  32 /*G:030
  33  * But first, how does our Guest contact the Host to ask for privileged
  34  * operations?  There are two ways: the direct way is to make a "hypercall",
  35  * to make requests of the Host Itself.
  36  *
  37  * Our hypercall mechanism uses the highest unused trap code (traps 32 and
  38  * above are used by real hardware interrupts).  Seventeen hypercalls are
  39  * available: the hypercall number is put in the %eax register, and the
  40  * arguments (when required) are placed in %ebx, %ecx, %edx and %esi.
  41  * If a return value makes sense, it's returned in %eax.
  42  *
  43  * Grossly invalid calls result in Sudden Death at the hands of the vengeful
  44  * Host, rather than returning failure.  This reflects Winston Churchill's
  45  * definition of a gentleman: "someone who is only rude intentionally".
  46  */
  47 static inline unsigned long
  48 hcall(unsigned long call,
  49       unsigned long arg1, unsigned long arg2, unsigned long arg3,
  50       unsigned long arg4)
  51 {
  52         /* "int" is the Intel instruction to trigger a trap. */
  53         asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
  54                      /* The call in %eax (aka "a") might be overwritten */
  55                      : "=a"(call)
  56                        /* The arguments are in %eax, %ebx, %ecx, %edx & %esi */
  57                      : "a"(call), "b"(arg1), "c"(arg2), "d"(arg3), "S"(arg4)
  58                        /* "memory" means this might write somewhere in memory.
  59                         * This isn't true for all calls, but it's safe to tell
  60                         * gcc that it might happen so it doesn't get clever. */
  61                      : "memory");
  62         return call;
  63 }
  64 /*:*/
  65
  66 /* Can't use our min() macro here: needs to be a constant */
  67 #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
  68
  69 #define LHCALL_RING_SIZE 64
  70 struct hcall_args {
  71         /* These map directly onto eax/ebx/ecx/edx/esi in struct lguest_regs */
  72         unsigned long arg0, arg1, arg2, arg3, arg4;
  73 };
  74
  75 #endif /* !__ASSEMBLY__ */
  76 #endif /* _ASM_X86_LGUEST_HCALL_H */