include/asm-x86/xen/interface.h

/******************************************************************************
 * arch-x86_32.h
 *
 * Guest OS interface to x86 32-bit Xen.
 *
 * Copyright (c) 2004, K A Fraser
 */

#ifndef __XEN_PUBLIC_ARCH_X86_32_H__
#define __XEN_PUBLIC_ARCH_X86_32_H__

#ifdef __XEN__
#define __DEFINE_GUEST_HANDLE(name, type) \
    typedef struct { type *p; } __guest_handle_ ## name
#else
#define __DEFINE_GUEST_HANDLE(name, type) \
    typedef type * __guest_handle_ ## name
#endif

#define DEFINE_GUEST_HANDLE_STRUCT(name) \
	__DEFINE_GUEST_HANDLE(name, struct name)
#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
#define GUEST_HANDLE(name)        __guest_handle_ ## name

#ifdef __XEN__
#if defined(__i386__)
#define set_xen_guest_handle(hnd, val)			\
	do {						\
		if (sizeof(hnd) == 8)			\
			*(uint64_t *)&(hnd) = 0;	\
		(hnd).p = val;				\
	} while (0)
#elif defined(__x86_64__)
#define set_xen_guest_handle(hnd, val)	do { (hnd).p = val; } while (0)
#endif
#else
#if defined(__i386__)
#define set_xen_guest_handle(hnd, val)			\
	do {						\
		if (sizeof(hnd) == 8)			\
			*(uint64_t *)&(hnd) = 0;	\
		(hnd) = val;				\
	} while (0)
#elif defined(__x86_64__)
#define set_xen_guest_handle(hnd, val)	do { (hnd) = val; } while (0)
#endif
#endif

#ifndef __ASSEMBLY__
/* Guest handles for primitive C types. */
__DEFINE_GUEST_HANDLE(uchar, unsigned char);
__DEFINE_GUEST_HANDLE(uint,  unsigned int);
__DEFINE_GUEST_HANDLE(ulong, unsigned long);
DEFINE_GUEST_HANDLE(char);
DEFINE_GUEST_HANDLE(int);
DEFINE_GUEST_HANDLE(long);
DEFINE_GUEST_HANDLE(void);
#endif

/*
 * SEGMENT DESCRIPTOR TABLES
 */
/*
 * A number of GDT entries are reserved by Xen. These are not situated at the
 * start of the GDT because some stupid OSes export hard-coded selector values
 * in their ABI. These hard-coded values are always near the start of the GDT,
 * so Xen places itself out of the way, at the far end of the GDT.
 */
#define FIRST_RESERVED_GDT_PAGE  14
#define FIRST_RESERVED_GDT_BYTE  (FIRST_RESERVED_GDT_PAGE * 4096)
#define FIRST_RESERVED_GDT_ENTRY (FIRST_RESERVED_GDT_BYTE / 8)

/*
 * These flat segments are in the Xen-private section of every GDT. Since these
 * are also present in the initial GDT, many OSes will be able to avoid
 * installing their own GDT.
 */
#define FLAT_RING1_CS 0xe019    /* GDT index 259 */
#define FLAT_RING1_DS 0xe021    /* GDT index 260 */
#define FLAT_RING1_SS 0xe021    /* GDT index 260 */
#define FLAT_RING3_CS 0xe02b    /* GDT index 261 */
#define FLAT_RING3_DS 0xe033    /* GDT index 262 */
#define FLAT_RING3_SS 0xe033    /* GDT index 262 */

#define FLAT_KERNEL_CS FLAT_RING1_CS
#define FLAT_KERNEL_DS FLAT_RING1_DS
#define FLAT_KERNEL_SS FLAT_RING1_SS
#define FLAT_USER_CS    FLAT_RING3_CS
#define FLAT_USER_DS    FLAT_RING3_DS
#define FLAT_USER_SS    FLAT_RING3_SS

/* And the trap vector is... */
#define TRAP_INSTR "int $0x82"

/*
 * Virtual addresses beyond this are not modifiable by guest OSes. The
 * machine->physical mapping table starts at this address, read-only.
 */
#ifdef CONFIG_X86_PAE
#define __HYPERVISOR_VIRT_START 0xF5800000
#else
#define __HYPERVISOR_VIRT_START 0xFC000000
#endif

#ifndef HYPERVISOR_VIRT_START
#define HYPERVISOR_VIRT_START mk_unsigned_long(__HYPERVISOR_VIRT_START)
#endif

#ifndef machine_to_phys_mapping
#define machine_to_phys_mapping ((unsigned long *)HYPERVISOR_VIRT_START)
#endif

/* Maximum number of virtual CPUs in multi-processor guests. */
#define MAX_VIRT_CPUS 32

#ifndef __ASSEMBLY__

/*
 * Send an array of these to HYPERVISOR_set_trap_table()
 */
#define TI_GET_DPL(_ti)		((_ti)->flags & 3)
#define TI_GET_IF(_ti)		((_ti)->flags & 4)
#define TI_SET_DPL(_ti, _dpl)	((_ti)->flags |= (_dpl))
#define TI_SET_IF(_ti, _if)	((_ti)->flags |= ((!!(_if))<<2))

struct trap_info {
    uint8_t       vector;  /* exception vector                              */
    uint8_t       flags;   /* 0-3: privilege level; 4: clear event enable?  */
    uint16_t      cs;      /* code selector                                 */
    unsigned long address; /* code offset                                   */
};
DEFINE_GUEST_HANDLE_STRUCT(trap_info);

struct cpu_user_regs {
    uint32_t ebx;
    uint32_t ecx;
    uint32_t edx;
    uint32_t esi;
    uint32_t edi;
    uint32_t ebp;
    uint32_t eax;
    uint16_t error_code;    /* private */
    uint16_t entry_vector;  /* private */
    uint32_t eip;
    uint16_t cs;
    uint8_t  saved_upcall_mask;
    uint8_t  _pad0;
    uint32_t eflags;        /* eflags.IF == !saved_upcall_mask */
    uint32_t esp;
    uint16_t ss, _pad1;
    uint16_t es, _pad2;
    uint16_t ds, _pad3;
    uint16_t fs, _pad4;
    uint16_t gs, _pad5;
};
DEFINE_GUEST_HANDLE_STRUCT(cpu_user_regs);

typedef uint64_t tsc_timestamp_t; /* RDTSC timestamp */

/*
 * The following is all CPU context. Note that the fpu_ctxt block is filled
 * in by FXSAVE if the CPU has feature FXSR; otherwise FSAVE is used.
 */
struct vcpu_guest_context {
    /* FPU registers come first so they can be aligned for FXSAVE/FXRSTOR. */
    struct { char x[512]; } fpu_ctxt;       /* User-level FPU registers     */
#define VGCF_I387_VALID (1<<0)
#define VGCF_HVM_GUEST  (1<<1)
#define VGCF_IN_KERNEL  (1<<2)
    unsigned long flags;                    /* VGCF_* flags                 */
    struct cpu_user_regs user_regs;         /* User-level CPU registers     */
    struct trap_info trap_ctxt[256];        /* Virtual IDT                  */
    unsigned long ldt_base, ldt_ents;       /* LDT (linear address, # ents) */
    unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, # ents) */
    unsigned long kernel_ss, kernel_sp;     /* Virtual TSS (only SS1/SP1)   */
    unsigned long ctrlreg[8];               /* CR0-CR7 (control registers)  */
    unsigned long debugreg[8];              /* DB0-DB7 (debug registers)    */
    unsigned long event_callback_cs;        /* CS:EIP of event callback     */
    unsigned long event_callback_eip;
    unsigned long failsafe_callback_cs;     /* CS:EIP of failsafe callback  */
    unsigned long failsafe_callback_eip;
    unsigned long vm_assist;                /* VMASST_TYPE_* bitmap */
};
DEFINE_GUEST_HANDLE_STRUCT(vcpu_guest_context);

struct arch_shared_info {
    unsigned long max_pfn;                  /* max pfn that appears in table */
    /* Frame containing list of mfns containing list of mfns containing p2m. */
    unsigned long pfn_to_mfn_frame_list_list;
    unsigned long nmi_reason;
};

struct arch_vcpu_info {
    unsigned long cr2;
    unsigned long pad[5]; /* sizeof(struct vcpu_info) == 64 */
};

struct xen_callback {
	unsigned long cs;
	unsigned long eip;
};
#endif /* !__ASSEMBLY__ */

/*
 * Prefix forces emulation of some non-trapping instructions.
 * Currently only CPUID.
 */
#ifdef __ASSEMBLY__
#define XEN_EMULATE_PREFIX .byte 0x0f,0x0b,0x78,0x65,0x6e ;
#define XEN_CPUID          XEN_EMULATE_PREFIX cpuid
#else
#define XEN_EMULATE_PREFIX ".byte 0x0f,0x0b,0x78,0x65,0x6e ; "
#define XEN_CPUID          XEN_EMULATE_PREFIX "cpuid"
#endif

#endif