arch/x86/include/asm/xen/hypercall.h - kernel/msm-4.9 - Gitiles

 /******************************************************************************
  * hypercall.h
  *
  * Linux-specific hypervisor handling.
  *
  * Copyright (c) 2002-2004, K A Fraser
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version 2
  * as published by the Free Software Foundation; or, when distributed
  * separately from the Linux kernel or incorporated into other
  * software packages, subject to the following license:
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this source file (the "Software"), to deal in the Software without
  * restriction, including without limitation the rights to use, copy, modify,
  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
  * and to permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  * IN THE SOFTWARE.
  */

 #ifndef _ASM_X86_XEN_HYPERCALL_H
 #define _ASM_X86_XEN_HYPERCALL_H

 #include <linux/kernel.h>
 #include <linux/spinlock.h>
 #include <linux/errno.h>
 #include <linux/string.h>
 #include <linux/types.h>

 #include <trace/events/xen.h>

 #include <asm/page.h>
 #include <asm/pgtable.h>

 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
 #include <xen/interface/physdev.h>

 /*
  * The hypercall asms have to meet several constraints:
  * - Work on 32- and 64-bit.
  *    The two architectures put their arguments in different sets of
  *    registers.
  *
  * - Work around asm syntax quirks
  *    It isn't possible to specify one of the rNN registers in a
  *    constraint, so we use explicit register variables to get the
  *    args into the right place.
  *
  * - Mark all registers as potentially clobbered
  *    Even unused parameters can be clobbered by the hypervisor, so we
  *    need to make sure gcc knows it.
  *
  * - Avoid compiler bugs.
  *    This is the tricky part.  Because x86_32 has such a constrained
  *    register set, gcc versions below 4.3 have trouble generating
  *    code when all the arg registers and memory are trashed by the
  *    asm.  There are syntactically simpler ways of achieving the
  *    semantics below, but they cause the compiler to crash.
  *
  *    The only combination I found which works is:
  *     - assign the __argX variables first
  *     - list all actually used parameters as "+r" (__argX)
  *     - clobber the rest
  *
  * The result certainly isn't pretty, and it really shows up cpp's
  * weakness as as macro language.  Sorry.  (But let's just give thanks
  * there aren't more than 5 arguments...)
  */

 extern struct { char _entry[32]; } hypercall_page[];

 #define __HYPERCALL		"call hypercall_page+%c[offset]"
 #define __HYPERCALL_ENTRY(x)						\
 	[offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))

 #ifdef CONFIG_X86_32
 #define __HYPERCALL_RETREG	"eax"
 #define __HYPERCALL_ARG1REG	"ebx"
 #define __HYPERCALL_ARG2REG	"ecx"
 #define __HYPERCALL_ARG3REG	"edx"
 #define __HYPERCALL_ARG4REG	"esi"
 #define __HYPERCALL_ARG5REG	"edi"
 #else
 #define __HYPERCALL_RETREG	"rax"
 #define __HYPERCALL_ARG1REG	"rdi"
 #define __HYPERCALL_ARG2REG	"rsi"
 #define __HYPERCALL_ARG3REG	"rdx"
 #define __HYPERCALL_ARG4REG	"r10"
 #define __HYPERCALL_ARG5REG	"r8"
 #endif

 #define __HYPERCALL_DECLS						\
 	register unsigned long __res  asm(__HYPERCALL_RETREG);		\
 	register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
 	register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
 	register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
 	register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
 	register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;

 #define __HYPERCALL_0PARAM	"=r" (__res)
 #define __HYPERCALL_1PARAM	__HYPERCALL_0PARAM, "+r" (__arg1)
 #define __HYPERCALL_2PARAM	__HYPERCALL_1PARAM, "+r" (__arg2)
 #define __HYPERCALL_3PARAM	__HYPERCALL_2PARAM, "+r" (__arg3)
 #define __HYPERCALL_4PARAM	__HYPERCALL_3PARAM, "+r" (__arg4)
 #define __HYPERCALL_5PARAM	__HYPERCALL_4PARAM, "+r" (__arg5)

 #define __HYPERCALL_0ARG()
 #define __HYPERCALL_1ARG(a1)						\
 	__HYPERCALL_0ARG()		__arg1 = (unsigned long)(a1);
 #define __HYPERCALL_2ARG(a1,a2)						\
 	__HYPERCALL_1ARG(a1)		__arg2 = (unsigned long)(a2);
 #define __HYPERCALL_3ARG(a1,a2,a3)					\
 	__HYPERCALL_2ARG(a1,a2)		__arg3 = (unsigned long)(a3);
 #define __HYPERCALL_4ARG(a1,a2,a3,a4)					\
 	__HYPERCALL_3ARG(a1,a2,a3)	__arg4 = (unsigned long)(a4);
 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)				\
 	__HYPERCALL_4ARG(a1,a2,a3,a4)	__arg5 = (unsigned long)(a5);

 #define __HYPERCALL_CLOBBER5	"memory"
 #define __HYPERCALL_CLOBBER4	__HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
 #define __HYPERCALL_CLOBBER3	__HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
 #define __HYPERCALL_CLOBBER2	__HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
 #define __HYPERCALL_CLOBBER1	__HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
 #define __HYPERCALL_CLOBBER0	__HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG

 #define _hypercall0(type, name)						\
 ({									\
 	__HYPERCALL_DECLS;						\
 	__HYPERCALL_0ARG();						\
 	asm volatile (__HYPERCALL					\
 		      : __HYPERCALL_0PARAM				\
 		      : __HYPERCALL_ENTRY(name)				\
 		      : __HYPERCALL_CLOBBER0);				\
 	(type)__res;							\
 })

 #define _hypercall1(type, name, a1)					\
 ({									\
 	__HYPERCALL_DECLS;						\
 	__HYPERCALL_1ARG(a1);						\
 	asm volatile (__HYPERCALL					\
 		      : __HYPERCALL_1PARAM				\
 		      : __HYPERCALL_ENTRY(name)				\
 		      : __HYPERCALL_CLOBBER1);				\
 	(type)__res;							\
 })

 #define _hypercall2(type, name, a1, a2)					\
 ({									\
 	__HYPERCALL_DECLS;						\
 	__HYPERCALL_2ARG(a1, a2);					\
 	asm volatile (__HYPERCALL					\
 		      : __HYPERCALL_2PARAM				\
 		      : __HYPERCALL_ENTRY(name)				\
 		      : __HYPERCALL_CLOBBER2);				\
 	(type)__res;							\
 })

 #define _hypercall3(type, name, a1, a2, a3)				\
 ({									\
 	__HYPERCALL_DECLS;						\
 	__HYPERCALL_3ARG(a1, a2, a3);					\
 	asm volatile (__HYPERCALL					\
 		      : __HYPERCALL_3PARAM				\
 		      : __HYPERCALL_ENTRY(name)				\
 		      : __HYPERCALL_CLOBBER3);				\
 	(type)__res;							\
 })

 #define _hypercall4(type, name, a1, a2, a3, a4)				\
 ({									\
 	__HYPERCALL_DECLS;						\
 	__HYPERCALL_4ARG(a1, a2, a3, a4);				\
 	asm volatile (__HYPERCALL					\
 		      : __HYPERCALL_4PARAM				\
 		      : __HYPERCALL_ENTRY(name)				\
 		      : __HYPERCALL_CLOBBER4);				\
 	(type)__res;							\
 })

 #define _hypercall5(type, name, a1, a2, a3, a4, a5)			\
 ({									\
 	__HYPERCALL_DECLS;						\
 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);				\
 	asm volatile (__HYPERCALL					\
 		      : __HYPERCALL_5PARAM				\
 		      : __HYPERCALL_ENTRY(name)				\
 		      : __HYPERCALL_CLOBBER5);				\
 	(type)__res;							\
 })

 static inline long
 privcmd_call(unsigned call,
 	     unsigned long a1, unsigned long a2,
 	     unsigned long a3, unsigned long a4,
 	     unsigned long a5)
 {
 	__HYPERCALL_DECLS;
 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);

 	asm volatile("call *%[call]"
 		     : __HYPERCALL_5PARAM
 		     : [call] "a" (&hypercall_page[call])
 		     : __HYPERCALL_CLOBBER5);

 	return (long)__res;
 }

 static inline int
 HYPERVISOR_set_trap_table(struct trap_info *table)
 {
 	return _hypercall1(int, set_trap_table, table);
 }

 static inline int
 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 		      int *success_count, domid_t domid)
 {
 	return _hypercall4(int, mmu_update, req, count, success_count, domid);
 }

 static inline int
 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 		     int *success_count, domid_t domid)
 {
 	return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 }

 static inline int
 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 {
 	return _hypercall2(int, set_gdt, frame_list, entries);
 }

 static inline int
 HYPERVISOR_stack_switch(unsigned long ss, unsigned long esp)
 {
 	return _hypercall2(int, stack_switch, ss, esp);
 }

 #ifdef CONFIG_X86_32
 static inline int
 HYPERVISOR_set_callbacks(unsigned long event_selector,
 			 unsigned long event_address,
 			 unsigned long failsafe_selector,
 			 unsigned long failsafe_address)
 {
 	return _hypercall4(int, set_callbacks,
 			   event_selector, event_address,
 			   failsafe_selector, failsafe_address);
 }
 #else  /* CONFIG_X86_64 */
 static inline int
 HYPERVISOR_set_callbacks(unsigned long event_address,
 			unsigned long failsafe_address,
 			unsigned long syscall_address)
 {
 	return _hypercall3(int, set_callbacks,
 			   event_address, failsafe_address,
 			   syscall_address);
 }
 #endif  /* CONFIG_X86_{32,64} */

 static inline int
 HYPERVISOR_callback_op(int cmd, void *arg)
 {
 	return _hypercall2(int, callback_op, cmd, arg);
 }

 static inline int
 HYPERVISOR_fpu_taskswitch(int set)
 {
 	return _hypercall1(int, fpu_taskswitch, set);
 }

 static inline int
 HYPERVISOR_sched_op(int cmd, void *arg)
 {
 	return _hypercall2(int, sched_op, cmd, arg);
 }

 static inline long
 HYPERVISOR_set_timer_op(u64 timeout)
 {
 	unsigned long timeout_hi = (unsigned long)(timeout>>32);
 	unsigned long timeout_lo = (unsigned long)timeout;
 	return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 }

 static inline int
 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 {
 	return _hypercall2(int, set_debugreg, reg, value);
 }

 static inline unsigned long
 HYPERVISOR_get_debugreg(int reg)
 {
 	return _hypercall1(unsigned long, get_debugreg, reg);
 }

 static inline int
 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 {
 	if (sizeof(u64) == sizeof(long))
 		return _hypercall2(int, update_descriptor, ma, desc);
 	return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 }

 static inline int
 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 {
 	return _hypercall2(int, memory_op, cmd, arg);
 }

 static inline int
 HYPERVISOR_multicall(void *call_list, int nr_calls)
 {
 	return _hypercall2(int, multicall, call_list, nr_calls);
 }

 static inline int
 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 			     unsigned long flags)
 {
 	if (sizeof(new_val) == sizeof(long))
 		return _hypercall3(int, update_va_mapping, va,
 				   new_val.pte, flags);
 	else
 		return _hypercall4(int, update_va_mapping, va,
 				   new_val.pte, new_val.pte >> 32, flags);
 }

 static inline int
 HYPERVISOR_event_channel_op(int cmd, void *arg)
 {
 	int rc = _hypercall2(int, event_channel_op, cmd, arg);
 	if (unlikely(rc == -ENOSYS)) {
 		struct evtchn_op op;
 		op.cmd = cmd;
 		memcpy(&op.u, arg, sizeof(op.u));
 		rc = _hypercall1(int, event_channel_op_compat, &op);
 		memcpy(arg, &op.u, sizeof(op.u));
 	}
 	return rc;
 }

 static inline int
 HYPERVISOR_xen_version(int cmd, void *arg)
 {
 	return _hypercall2(int, xen_version, cmd, arg);
 }

 static inline int
 HYPERVISOR_console_io(int cmd, int count, char *str)
 {
 	return _hypercall3(int, console_io, cmd, count, str);
 }

 static inline int
 HYPERVISOR_physdev_op(int cmd, void *arg)
 {
 	int rc = _hypercall2(int, physdev_op, cmd, arg);
 	if (unlikely(rc == -ENOSYS)) {
 		struct physdev_op op;
 		op.cmd = cmd;
 		memcpy(&op.u, arg, sizeof(op.u));
 		rc = _hypercall1(int, physdev_op_compat, &op);
 		memcpy(arg, &op.u, sizeof(op.u));
 	}
 	return rc;
 }

 static inline int
 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 {
 	return _hypercall3(int, grant_table_op, cmd, uop, count);
 }

 static inline int
 HYPERVISOR_update_va_mapping_otherdomain(unsigned long va, pte_t new_val,
 					 unsigned long flags, domid_t domid)
 {
 	if (sizeof(new_val) == sizeof(long))
 		return _hypercall4(int, update_va_mapping_otherdomain, va,
 				   new_val.pte, flags, domid);
 	else
 		return _hypercall5(int, update_va_mapping_otherdomain, va,
 				   new_val.pte, new_val.pte >> 32,
 				   flags, domid);
 }

 static inline int
 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 {
 	return _hypercall2(int, vm_assist, cmd, type);
 }

 static inline int
 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 {
 	return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 }

 #ifdef CONFIG_X86_64
 static inline int
 HYPERVISOR_set_segment_base(int reg, unsigned long value)
 {
 	return _hypercall2(int, set_segment_base, reg, value);
 }
 #endif

 static inline int
 HYPERVISOR_suspend(unsigned long start_info_mfn)
 {
 	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };

 	/*
 	 * For a PV guest the tools require that the start_info mfn be
 	 * present in rdx/edx when the hypercall is made. Per the
 	 * hypercall calling convention this is the third hypercall
 	 * argument, which is start_info_mfn here.
 	 */
 	return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 }

 static inline int
 HYPERVISOR_nmi_op(unsigned long op, unsigned long arg)
 {
 	return _hypercall2(int, nmi_op, op, arg);
 }

 static inline unsigned long __must_check
 HYPERVISOR_hvm_op(int op, void *arg)
 {
        return _hypercall2(unsigned long, hvm_op, op, arg);
 }

 static inline int
 HYPERVISOR_tmem_op(
 	struct tmem_op *op)
 {
 	return _hypercall1(int, tmem_op, op);
 }

 static inline void
 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 {
 	mcl->op = __HYPERVISOR_fpu_taskswitch;
 	mcl->args[0] = set;

 	trace_xen_mc_entry(mcl, 1);
 }

 static inline void
 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 			pte_t new_val, unsigned long flags)
 {
 	mcl->op = __HYPERVISOR_update_va_mapping;
 	mcl->args[0] = va;
 	if (sizeof(new_val) == sizeof(long)) {
 		mcl->args[1] = new_val.pte;
 		mcl->args[2] = flags;
 	} else {
 		mcl->args[1] = new_val.pte;
 		mcl->args[2] = new_val.pte >> 32;
 		mcl->args[3] = flags;
 	}

 	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
 }

 static inline void
 MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
 		     void *uop, unsigned int count)
 {
 	mcl->op = __HYPERVISOR_grant_table_op;
 	mcl->args[0] = cmd;
 	mcl->args[1] = (unsigned long)uop;
 	mcl->args[2] = count;

 	trace_xen_mc_entry(mcl, 3);
 }

 static inline void
 MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long va,
 				    pte_t new_val, unsigned long flags,
 				    domid_t domid)
 {
 	mcl->op = __HYPERVISOR_update_va_mapping_otherdomain;
 	mcl->args[0] = va;
 	if (sizeof(new_val) == sizeof(long)) {
 		mcl->args[1] = new_val.pte;
 		mcl->args[2] = flags;
 		mcl->args[3] = domid;
 	} else {
 		mcl->args[1] = new_val.pte;
 		mcl->args[2] = new_val.pte >> 32;
 		mcl->args[3] = flags;
 		mcl->args[4] = domid;
 	}

 	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 4 : 5);
 }

 static inline void
 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 			struct desc_struct desc)
 {
 	mcl->op = __HYPERVISOR_update_descriptor;
 	if (sizeof(maddr) == sizeof(long)) {
 		mcl->args[0] = maddr;
 		mcl->args[1] = *(unsigned long *)&desc;
 	} else {
 		mcl->args[0] = maddr;
 		mcl->args[1] = maddr >> 32;
 		mcl->args[2] = desc.a;
 		mcl->args[3] = desc.b;
 	}

 	trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
 }

 static inline void
 MULTI_memory_op(struct multicall_entry *mcl, unsigned int cmd, void *arg)
 {
 	mcl->op = __HYPERVISOR_memory_op;
 	mcl->args[0] = cmd;
 	mcl->args[1] = (unsigned long)arg;

 	trace_xen_mc_entry(mcl, 2);
 }

 static inline void
 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 		 int count, int *success_count, domid_t domid)
 {
 	mcl->op = __HYPERVISOR_mmu_update;
 	mcl->args[0] = (unsigned long)req;
 	mcl->args[1] = count;
 	mcl->args[2] = (unsigned long)success_count;
 	mcl->args[3] = domid;

 	trace_xen_mc_entry(mcl, 4);
 }

 static inline void
 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 		int *success_count, domid_t domid)
 {
 	mcl->op = __HYPERVISOR_mmuext_op;
 	mcl->args[0] = (unsigned long)op;
 	mcl->args[1] = count;
 	mcl->args[2] = (unsigned long)success_count;
 	mcl->args[3] = domid;

 	trace_xen_mc_entry(mcl, 4);
 }

 static inline void
 MULTI_set_gdt(struct multicall_entry *mcl, unsigned long *frames, int entries)
 {
 	mcl->op = __HYPERVISOR_set_gdt;
 	mcl->args[0] = (unsigned long)frames;
 	mcl->args[1] = entries;

 	trace_xen_mc_entry(mcl, 2);
 }

 static inline void
 MULTI_stack_switch(struct multicall_entry *mcl,
 		   unsigned long ss, unsigned long esp)
 {
 	mcl->op = __HYPERVISOR_stack_switch;
 	mcl->args[0] = ss;
 	mcl->args[1] = esp;

 	trace_xen_mc_entry(mcl, 2);
 }

 #endif /* _ASM_X86_XEN_HYPERCALL_H */
	/******************************************************************************
	* hypercall.h
	*
	* Linux-specific hypervisor handling.
	*
	* Copyright (c) 2002-2004, K A Fraser
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License version 2
	* as published by the Free Software Foundation; or, when distributed
	* separately from the Linux kernel or incorporated into other
	* software packages, subject to the following license:
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this source file (the "Software"), to deal in the Software without
	* restriction, including without limitation the rights to use, copy, modify,
	* merge, publish, distribute, sublicense, and/or sell copies of the Software,
	* and to permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
	* IN THE SOFTWARE.
	*/

	#ifndef _ASM_X86_XEN_HYPERCALL_H
	#define _ASM_X86_XEN_HYPERCALL_H

	#include <linux/kernel.h>
	#include <linux/spinlock.h>
	#include <linux/errno.h>
	#include <linux/string.h>
	#include <linux/types.h>

	#include <trace/events/xen.h>

	#include <asm/page.h>
	#include <asm/pgtable.h>

	#include <xen/interface/xen.h>
	#include <xen/interface/sched.h>
	#include <xen/interface/physdev.h>

	/*
	* The hypercall asms have to meet several constraints:
	* - Work on 32- and 64-bit.
	* The two architectures put their arguments in different sets of
	* registers.
	*
	* - Work around asm syntax quirks
	* It isn't possible to specify one of the rNN registers in a
	* constraint, so we use explicit register variables to get the
	* args into the right place.
	*
	* - Mark all registers as potentially clobbered
	* Even unused parameters can be clobbered by the hypervisor, so we
	* need to make sure gcc knows it.
	*
	* - Avoid compiler bugs.
	* This is the tricky part. Because x86_32 has such a constrained
	* register set, gcc versions below 4.3 have trouble generating
	* code when all the arg registers and memory are trashed by the
	* asm. There are syntactically simpler ways of achieving the
	* semantics below, but they cause the compiler to crash.
	*
	* The only combination I found which works is:
	* - assign the __argX variables first
	* - list all actually used parameters as "+r" (__argX)
	* - clobber the rest
	*
	* The result certainly isn't pretty, and it really shows up cpp's
	* weakness as as macro language. Sorry. (But let's just give thanks
	* there aren't more than 5 arguments...)
	*/

	extern struct { char _entry[32]; } hypercall_page[];

	#define __HYPERCALL "call hypercall_page+%c[offset]"
	#define __HYPERCALL_ENTRY(x) \
	[offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))

	#ifdef CONFIG_X86_32
	#define __HYPERCALL_RETREG "eax"
	#define __HYPERCALL_ARG1REG "ebx"
	#define __HYPERCALL_ARG2REG "ecx"
	#define __HYPERCALL_ARG3REG "edx"
	#define __HYPERCALL_ARG4REG "esi"
	#define __HYPERCALL_ARG5REG "edi"
	#else
	#define __HYPERCALL_RETREG "rax"
	#define __HYPERCALL_ARG1REG "rdi"
	#define __HYPERCALL_ARG2REG "rsi"
	#define __HYPERCALL_ARG3REG "rdx"
	#define __HYPERCALL_ARG4REG "r10"
	#define __HYPERCALL_ARG5REG "r8"
	#endif

	#define __HYPERCALL_DECLS \
	register unsigned long __res asm(__HYPERCALL_RETREG); \
	register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
	register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
	register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
	register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
	register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;

	#define __HYPERCALL_0PARAM "=r" (__res)
	#define __HYPERCALL_1PARAM __HYPERCALL_0PARAM, "+r" (__arg1)
	#define __HYPERCALL_2PARAM __HYPERCALL_1PARAM, "+r" (__arg2)
	#define __HYPERCALL_3PARAM __HYPERCALL_2PARAM, "+r" (__arg3)
	#define __HYPERCALL_4PARAM __HYPERCALL_3PARAM, "+r" (__arg4)
	#define __HYPERCALL_5PARAM __HYPERCALL_4PARAM, "+r" (__arg5)

	#define __HYPERCALL_0ARG()
	#define __HYPERCALL_1ARG(a1) \
	__HYPERCALL_0ARG() __arg1 = (unsigned long)(a1);
	#define __HYPERCALL_2ARG(a1,a2) \
	__HYPERCALL_1ARG(a1) __arg2 = (unsigned long)(a2);
	#define __HYPERCALL_3ARG(a1,a2,a3) \
	__HYPERCALL_2ARG(a1,a2) __arg3 = (unsigned long)(a3);
	#define __HYPERCALL_4ARG(a1,a2,a3,a4) \
	__HYPERCALL_3ARG(a1,a2,a3) __arg4 = (unsigned long)(a4);
	#define __HYPERCALL_5ARG(a1,a2,a3,a4,a5) \
	__HYPERCALL_4ARG(a1,a2,a3,a4) __arg5 = (unsigned long)(a5);

	#define __HYPERCALL_CLOBBER5 "memory"
	#define __HYPERCALL_CLOBBER4 __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
	#define __HYPERCALL_CLOBBER3 __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
	#define __HYPERCALL_CLOBBER2 __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
	#define __HYPERCALL_CLOBBER1 __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
	#define __HYPERCALL_CLOBBER0 __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG

	#define _hypercall0(type, name) \
	({ \
	__HYPERCALL_DECLS; \
	__HYPERCALL_0ARG(); \
	asm volatile (__HYPERCALL \
	: __HYPERCALL_0PARAM \
	: __HYPERCALL_ENTRY(name) \
	: __HYPERCALL_CLOBBER0); \
	(type)__res; \
	})

	#define _hypercall1(type, name, a1) \
	({ \
	__HYPERCALL_DECLS; \
	__HYPERCALL_1ARG(a1); \
	asm volatile (__HYPERCALL \
	: __HYPERCALL_1PARAM \
	: __HYPERCALL_ENTRY(name) \
	: __HYPERCALL_CLOBBER1); \
	(type)__res; \
	})

	#define _hypercall2(type, name, a1, a2) \
	({ \
	__HYPERCALL_DECLS; \
	__HYPERCALL_2ARG(a1, a2); \
	asm volatile (__HYPERCALL \
	: __HYPERCALL_2PARAM \
	: __HYPERCALL_ENTRY(name) \
	: __HYPERCALL_CLOBBER2); \
	(type)__res; \
	})

	#define _hypercall3(type, name, a1, a2, a3) \
	({ \
	__HYPERCALL_DECLS; \
	__HYPERCALL_3ARG(a1, a2, a3); \
	asm volatile (__HYPERCALL \
	: __HYPERCALL_3PARAM \
	: __HYPERCALL_ENTRY(name) \
	: __HYPERCALL_CLOBBER3); \
	(type)__res; \
	})

	#define _hypercall4(type, name, a1, a2, a3, a4) \
	({ \
	__HYPERCALL_DECLS; \
	__HYPERCALL_4ARG(a1, a2, a3, a4); \
	asm volatile (__HYPERCALL \
	: __HYPERCALL_4PARAM \
	: __HYPERCALL_ENTRY(name) \
	: __HYPERCALL_CLOBBER4); \
	(type)__res; \
	})

	#define _hypercall5(type, name, a1, a2, a3, a4, a5) \
	({ \
	__HYPERCALL_DECLS; \
	__HYPERCALL_5ARG(a1, a2, a3, a4, a5); \
	asm volatile (__HYPERCALL \
	: __HYPERCALL_5PARAM \
	: __HYPERCALL_ENTRY(name) \
	: __HYPERCALL_CLOBBER5); \
	(type)__res; \
	})

	static inline long
	privcmd_call(unsigned call,
	unsigned long a1, unsigned long a2,
	unsigned long a3, unsigned long a4,
	unsigned long a5)
	{
	__HYPERCALL_DECLS;
	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);

	asm volatile("call *%[call]"
	: __HYPERCALL_5PARAM
	: [call] "a" (&hypercall_page[call])
	: __HYPERCALL_CLOBBER5);

	return (long)__res;
	}

	static inline int
	HYPERVISOR_set_trap_table(struct trap_info *table)
	{
	return _hypercall1(int, set_trap_table, table);
	}

	static inline int
	HYPERVISOR_mmu_update(struct mmu_update *req, int count,
	int *success_count, domid_t domid)
	{
	return _hypercall4(int, mmu_update, req, count, success_count, domid);
	}

	static inline int
	HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
	int *success_count, domid_t domid)
	{
	return _hypercall4(int, mmuext_op, op, count, success_count, domid);
	}

	static inline int
	HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
	{
	return _hypercall2(int, set_gdt, frame_list, entries);
	}

	static inline int
	HYPERVISOR_stack_switch(unsigned long ss, unsigned long esp)
	{
	return _hypercall2(int, stack_switch, ss, esp);
	}

	#ifdef CONFIG_X86_32
	static inline int
	HYPERVISOR_set_callbacks(unsigned long event_selector,
	unsigned long event_address,
	unsigned long failsafe_selector,
	unsigned long failsafe_address)
	{
	return _hypercall4(int, set_callbacks,
	event_selector, event_address,
	failsafe_selector, failsafe_address);
	}
	#else /* CONFIG_X86_64 */
	static inline int
	HYPERVISOR_set_callbacks(unsigned long event_address,
	unsigned long failsafe_address,
	unsigned long syscall_address)
	{
	return _hypercall3(int, set_callbacks,
	event_address, failsafe_address,
	syscall_address);
	}
	#endif /* CONFIG_X86_{32,64} */

	static inline int
	HYPERVISOR_callback_op(int cmd, void *arg)
	{
	return _hypercall2(int, callback_op, cmd, arg);
	}

	static inline int
	HYPERVISOR_fpu_taskswitch(int set)
	{
	return _hypercall1(int, fpu_taskswitch, set);
	}

	static inline int
	HYPERVISOR_sched_op(int cmd, void *arg)
	{
	return _hypercall2(int, sched_op, cmd, arg);
	}

	static inline long
	HYPERVISOR_set_timer_op(u64 timeout)
	{
	unsigned long timeout_hi = (unsigned long)(timeout>>32);
	unsigned long timeout_lo = (unsigned long)timeout;
	return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
	}

	static inline int
	HYPERVISOR_set_debugreg(int reg, unsigned long value)
	{
	return _hypercall2(int, set_debugreg, reg, value);
	}

	static inline unsigned long
	HYPERVISOR_get_debugreg(int reg)
	{
	return _hypercall1(unsigned long, get_debugreg, reg);
	}

	static inline int
	HYPERVISOR_update_descriptor(u64 ma, u64 desc)
	{
	if (sizeof(u64) == sizeof(long))
	return _hypercall2(int, update_descriptor, ma, desc);
	return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
	}

	static inline int
	HYPERVISOR_memory_op(unsigned int cmd, void *arg)
	{
	return _hypercall2(int, memory_op, cmd, arg);
	}

	static inline int
	HYPERVISOR_multicall(void *call_list, int nr_calls)
	{
	return _hypercall2(int, multicall, call_list, nr_calls);
	}

	static inline int
	HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
	unsigned long flags)
	{
	if (sizeof(new_val) == sizeof(long))
	return _hypercall3(int, update_va_mapping, va,
	new_val.pte, flags);
	else
	return _hypercall4(int, update_va_mapping, va,
	new_val.pte, new_val.pte >> 32, flags);
	}

	static inline int
	HYPERVISOR_event_channel_op(int cmd, void *arg)
	{
	int rc = _hypercall2(int, event_channel_op, cmd, arg);
	if (unlikely(rc == -ENOSYS)) {
	struct evtchn_op op;
	op.cmd = cmd;
	memcpy(&op.u, arg, sizeof(op.u));
	rc = _hypercall1(int, event_channel_op_compat, &op);
	memcpy(arg, &op.u, sizeof(op.u));
	}
	return rc;
	}

	static inline int
	HYPERVISOR_xen_version(int cmd, void *arg)
	{
	return _hypercall2(int, xen_version, cmd, arg);
	}

	static inline int
	HYPERVISOR_console_io(int cmd, int count, char *str)
	{
	return _hypercall3(int, console_io, cmd, count, str);
	}

	static inline int
	HYPERVISOR_physdev_op(int cmd, void *arg)
	{
	int rc = _hypercall2(int, physdev_op, cmd, arg);
	if (unlikely(rc == -ENOSYS)) {
	struct physdev_op op;
	op.cmd = cmd;
	memcpy(&op.u, arg, sizeof(op.u));
	rc = _hypercall1(int, physdev_op_compat, &op);
	memcpy(arg, &op.u, sizeof(op.u));
	}
	return rc;
	}

	static inline int
	HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
	{
	return _hypercall3(int, grant_table_op, cmd, uop, count);
	}

	static inline int
	HYPERVISOR_update_va_mapping_otherdomain(unsigned long va, pte_t new_val,
	unsigned long flags, domid_t domid)
	{
	if (sizeof(new_val) == sizeof(long))
	return _hypercall4(int, update_va_mapping_otherdomain, va,
	new_val.pte, flags, domid);
	else
	return _hypercall5(int, update_va_mapping_otherdomain, va,
	new_val.pte, new_val.pte >> 32,
	flags, domid);
	}

	static inline int
	HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
	{
	return _hypercall2(int, vm_assist, cmd, type);
	}

	static inline int
	HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
	{
	return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
	}

	#ifdef CONFIG_X86_64
	static inline int
	HYPERVISOR_set_segment_base(int reg, unsigned long value)
	{
	return _hypercall2(int, set_segment_base, reg, value);
	}
	#endif

	static inline int
	HYPERVISOR_suspend(unsigned long start_info_mfn)
	{
	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };

	/*
	* For a PV guest the tools require that the start_info mfn be
	* present in rdx/edx when the hypercall is made. Per the
	* hypercall calling convention this is the third hypercall
	* argument, which is start_info_mfn here.
	*/
	return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
	}

	static inline int
	HYPERVISOR_nmi_op(unsigned long op, unsigned long arg)
	{
	return _hypercall2(int, nmi_op, op, arg);
	}

	static inline unsigned long __must_check
	HYPERVISOR_hvm_op(int op, void *arg)
	{
	return _hypercall2(unsigned long, hvm_op, op, arg);
	}

	static inline int
	HYPERVISOR_tmem_op(
	struct tmem_op *op)
	{
	return _hypercall1(int, tmem_op, op);
	}

	static inline void
	MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
	{
	mcl->op = __HYPERVISOR_fpu_taskswitch;
	mcl->args[0] = set;

	trace_xen_mc_entry(mcl, 1);
	}

	static inline void
	MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
	pte_t new_val, unsigned long flags)
	{
	mcl->op = __HYPERVISOR_update_va_mapping;
	mcl->args[0] = va;
	if (sizeof(new_val) == sizeof(long)) {
	mcl->args[1] = new_val.pte;
	mcl->args[2] = flags;
	} else {
	mcl->args[1] = new_val.pte;
	mcl->args[2] = new_val.pte >> 32;
	mcl->args[3] = flags;
	}

	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
	}

	static inline void
	MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
	void *uop, unsigned int count)
	{
	mcl->op = __HYPERVISOR_grant_table_op;
	mcl->args[0] = cmd;
	mcl->args[1] = (unsigned long)uop;
	mcl->args[2] = count;

	trace_xen_mc_entry(mcl, 3);
	}

	static inline void
	MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long va,
	pte_t new_val, unsigned long flags,
	domid_t domid)
	{
	mcl->op = __HYPERVISOR_update_va_mapping_otherdomain;
	mcl->args[0] = va;
	if (sizeof(new_val) == sizeof(long)) {
	mcl->args[1] = new_val.pte;
	mcl->args[2] = flags;
	mcl->args[3] = domid;
	} else {
	mcl->args[1] = new_val.pte;
	mcl->args[2] = new_val.pte >> 32;
	mcl->args[3] = flags;
	mcl->args[4] = domid;
	}

	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 4 : 5);
	}

	static inline void
	MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
	struct desc_struct desc)
	{
	mcl->op = __HYPERVISOR_update_descriptor;
	if (sizeof(maddr) == sizeof(long)) {
	mcl->args[0] = maddr;
	mcl->args[1] = (unsigned long )&desc;
	} else {
	mcl->args[0] = maddr;
	mcl->args[1] = maddr >> 32;
	mcl->args[2] = desc.a;
	mcl->args[3] = desc.b;
	}

	trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
	}

	static inline void
	MULTI_memory_op(struct multicall_entry mcl, unsigned int cmd, void arg)
	{
	mcl->op = __HYPERVISOR_memory_op;
	mcl->args[0] = cmd;
	mcl->args[1] = (unsigned long)arg;

	trace_xen_mc_entry(mcl, 2);
	}

	static inline void
	MULTI_mmu_update(struct multicall_entry mcl, struct mmu_update req,
	int count, int *success_count, domid_t domid)
	{
	mcl->op = __HYPERVISOR_mmu_update;
	mcl->args[0] = (unsigned long)req;
	mcl->args[1] = count;
	mcl->args[2] = (unsigned long)success_count;
	mcl->args[3] = domid;

	trace_xen_mc_entry(mcl, 4);
	}

	static inline void
	MULTI_mmuext_op(struct multicall_entry mcl, struct mmuext_op op, int count,
	int *success_count, domid_t domid)
	{
	mcl->op = __HYPERVISOR_mmuext_op;
	mcl->args[0] = (unsigned long)op;
	mcl->args[1] = count;
	mcl->args[2] = (unsigned long)success_count;
	mcl->args[3] = domid;

	trace_xen_mc_entry(mcl, 4);
	}

	static inline void
	MULTI_set_gdt(struct multicall_entry mcl, unsigned long frames, int entries)
	{
	mcl->op = __HYPERVISOR_set_gdt;
	mcl->args[0] = (unsigned long)frames;
	mcl->args[1] = entries;

	trace_xen_mc_entry(mcl, 2);
	}

	static inline void
	MULTI_stack_switch(struct multicall_entry *mcl,
	unsigned long ss, unsigned long esp)
	{
	mcl->op = __HYPERVISOR_stack_switch;
	mcl->args[0] = ss;
	mcl->args[1] = esp;

	trace_xen_mc_entry(mcl, 2);
	}

	#endif /* _ASM_X86_XEN_HYPERCALL_H */