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_SET_CLOCKEVENT   9
  13 #define LHCALL_HALT             10
  14 #define LHCALL_SET_PMD          13
  15 #define LHCALL_SET_PTE          14
  16 #define LHCALL_SET_PGD          15
  17 #define LHCALL_LOAD_TLS         16
  18 #define LHCALL_LOAD_GDT_ENTRY   18
  19 #define LHCALL_SEND_INTERRUPTS  19
  20
  21 #define LGUEST_TRAP_ENTRY 0x1F
  22
  23 /* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
  24 #define LGUEST_SHUTDOWN_POWEROFF        1
  25 #define LGUEST_SHUTDOWN_RESTART         2
  26
  27 #ifndef __ASSEMBLY__
  28 #include <asm/hw_irq.h>
  29
  30 /*G:030
  31  * But first, how does our Guest contact the Host to ask for privileged
  32  * operations?  There are two ways: the direct way is to make a "hypercall",
  33  * to make requests of the Host Itself.
  34  *
  35  * Our hypercall mechanism uses the highest unused trap code (traps 32 and
  36  * above are used by real hardware interrupts).  Seventeen hypercalls are
  37  * available: the hypercall number is put in the %eax register, and the
  38  * arguments (when required) are placed in %ebx, %ecx, %edx and %esi.
  39  * If a return value makes sense, it's returned in %eax.
  40  *
  41  * Grossly invalid calls result in Sudden Death at the hands of the vengeful
  42  * Host, rather than returning failure.  This reflects Winston Churchill's
  43  * definition of a gentleman: "someone who is only rude intentionally".
  44  */
  45 static inline unsigned long
  46 hcall(unsigned long call,
  47       unsigned long arg1, unsigned long arg2, unsigned long arg3,
  48       unsigned long arg4)
  49 {
  50         /* "int" is the Intel instruction to trigger a trap. */
  51         asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
  52                      /* The call in %eax (aka "a") might be overwritten */
  53                      : "=a"(call)
  54                        /* The arguments are in %eax, %ebx, %ecx, %edx & %esi */
  55                      : "a"(call), "b"(arg1), "c"(arg2), "d"(arg3), "S"(arg4)
  56                        /* "memory" means this might write somewhere in memory.
  57                         * This isn't true for all calls, but it's safe to tell
  58                         * gcc that it might happen so it doesn't get clever. */
  59                      : "memory");
  60         return call;
  61 }
  62 /*:*/
  63
  64 /* Can't use our min() macro here: needs to be a constant */
  65 #define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
  66
  67 #define LHCALL_RING_SIZE 64
  68 struct hcall_args {
  69         /* These map directly onto eax/ebx/ecx/edx/esi in struct lguest_regs */
  70         unsigned long arg0, arg1, arg2, arg3, arg4;
  71 };
  72
  73 #endif /* !__ASSEMBLY__ */
  74 #endif /* _ASM_X86_LGUEST_HCALL_H */