-/*G:031 First, how does our Guest contact the Host to ask for privileged
- * operations? There are two ways: the direct way is to make a "hypercall",
- * to make requests of the Host Itself.
- *
- * Our hypercall mechanism uses the highest unused trap code (traps 32 and
- * above are used by real hardware interrupts). Seventeen hypercalls are
- * available: the hypercall number is put in the %eax register, and the
- * arguments (when required) are placed in %edx, %ebx and %ecx. If a return
- * value makes sense, it's returned in %eax.
- *
- * Grossly invalid calls result in Sudden Death at the hands of the vengeful
- * Host, rather than returning failure. This reflects Winston Churchill's
- * definition of a gentleman: "someone who is only rude intentionally". */
-#define LGUEST_TRAP_ENTRY 0x1F
-
-static inline unsigned long
-hcall(unsigned long call,
- unsigned long arg1, unsigned long arg2, unsigned long arg3)
-{
- /* "int" is the Intel instruction to trigger a trap. */
- asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
- /* The call is in %eax (aka "a"), and can be replaced */
- : "=a"(call)
- /* The other arguments are in %eax, %edx, %ebx & %ecx */
- : "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
- /* "memory" means this might write somewhere in memory.
- * This isn't true for all calls, but it's safe to tell
- * gcc that it might happen so it doesn't get clever. */
- : "memory");
- return call;
-}
-/*:*/
-
-void async_hcall(unsigned long call,
- unsigned long arg1, unsigned long arg2, unsigned long arg3);
-
-/* Can't use our min() macro here: needs to be a constant */
-#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
-
-#define LHCALL_RING_SIZE 64
-struct hcall_ring
-{
- u32 eax, edx, ebx, ecx;
-};
-