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