[mirror_ubuntu-artful-kernel.git] / include / asm-x86 / lguest_hcall.h

/* Architecture specific portion of the lguest hypercalls */
#ifndef _X86_LGUEST_HCALL_H
#define _X86_LGUEST_HCALL_H

#define LHCALL_FLUSH_ASYNC	0
#define LHCALL_LGUEST_INIT	1
#define LHCALL_SHUTDOWN		2
#define LHCALL_LOAD_GDT		3
#define LHCALL_NEW_PGTABLE	4
#define LHCALL_FLUSH_TLB	5
#define LHCALL_LOAD_IDT_ENTRY	6
#define LHCALL_SET_STACK	7
#define LHCALL_TS		8
#define LHCALL_SET_CLOCKEVENT	9
#define LHCALL_HALT		10
#define LHCALL_SET_PTE		14
#define LHCALL_SET_PMD		15
#define LHCALL_LOAD_TLS		16
#define LHCALL_NOTIFY		17

#define LGUEST_TRAP_ENTRY 0x1F

/* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
#define LGUEST_SHUTDOWN_POWEROFF	1
#define LGUEST_SHUTDOWN_RESTART		2

#ifndef __ASSEMBLY__
#include <asm/hw_irq.h>

/*G:031 But 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).  Fifteen 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". */
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 in %eax (aka "a") might be overwritten */
		     : "=a"(call)
		       /* The 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;
}
/*:*/

/* 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_args
{
	/* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */
	unsigned long arg0, arg2, arg3, arg1;
};

#endif /* !__ASSEMBLY__ */
#endif	/* _I386_LGUEST_HCALL_H */
Commit	Line	Data
c37ae93d JS	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
ec04b13f	7	#define LHCALL_SHUTDOWN 2
c37ae93d JS	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
c37ae93d JS	16	#define LHCALL_SET_PTE 14
	17	#define LHCALL_SET_PMD 15
	18	#define LHCALL_LOAD_TLS 16
15045275	19	#define LHCALL_NOTIFY 17
c37ae93d	20
e1e72965 RR	21	#define LGUEST_TRAP_ENTRY 0x1F
e1e72965 RR	22
ec04b13f BR	23	/* Argument number 3 to LHCALL_LGUEST_SHUTDOWN */
	24	#define LGUEST_SHUTDOWN_POWEROFF 1
	25	#define LGUEST_SHUTDOWN_RESTART 2
	26
e1e72965 RR	27	#ifndef __ASSEMBLY__
	28	#include <asm/hw_irq.h>
	29
a6bd8e13	30	/*G:031 But first, how does our Guest contact the Host to ask for privileged
c37ae93d JS	31	* operations? There are two ways: the direct way is to make a "hypercall",
	32	* to make requests of the Host Itself.
	33	*
	34	* Our hypercall mechanism uses the highest unused trap code (traps 32 and
e1e72965	35	* above are used by real hardware interrupts). Fifteen hypercalls are
c37ae93d JS	36	* available: the hypercall number is put in the %eax register, and the
	37	* arguments (when required) are placed in %edx, %ebx and %ecx. If a return
	38	* value makes sense, it's returned in %eax.
	39	*
	40	* Grossly invalid calls result in Sudden Death at the hands of the vengeful
	41	* Host, rather than returning failure. This reflects Winston Churchill's
	42	* definition of a gentleman: "someone who is only rude intentionally". */
c37ae93d JS	43	static inline unsigned long
	44	hcall(unsigned long call,
	45	unsigned long arg1, unsigned long arg2, unsigned long arg3)
	46	{
	47	/* "int" is the Intel instruction to trigger a trap. */
	48	asm volatile("int $" __stringify(LGUEST_TRAP_ENTRY)
e1e72965	49	/* The call in %eax (aka "a") might be overwritten */
c37ae93d	50	: "=a"(call)
e1e72965	51	/* The arguments are in %eax, %edx, %ebx & %ecx */
c37ae93d JS	52	: "a"(call), "d"(arg1), "b"(arg2), "c"(arg3)
	53	/* "memory" means this might write somewhere in memory.
	54	* This isn't true for all calls, but it's safe to tell
	55	* gcc that it might happen so it doesn't get clever. */
	56	: "memory");
	57	return call;
	58	}
	59	/:/
	60
c37ae93d JS	61	/* Can't use our min() macro here: needs to be a constant */
	62	#define LGUEST_IRQS (NR_IRQS < 32 ? NR_IRQS: 32)
	63
	64	#define LHCALL_RING_SIZE 64
b410e7b1	65	struct hcall_args
c37ae93d	66	{
b410e7b1 JS	67	/* These map directly onto eax, ebx, ecx, edx in struct lguest_regs */
b410e7b1 JS	68	unsigned long arg0, arg2, arg3, arg1;
c37ae93d	69	};
47436aa4 RR	70
47436aa4 RR	71	#endif /* !__ASSEMBLY__ */
c37ae93d	72	#endif /* _I386_LGUEST_HCALL_H */