/******************************************************************************
 * 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__

/*
 * Hypercall interface:
 *  Input:  %ebx, %ecx, %edx, %esi, %edi (arguments 1-5)
 *  Output: %eax
 * Access is via hypercall page (set up by guest loader or via a Xen MSR):
 *  call hypercall_page + hypercall-number * 32
 * Clobbered: Argument registers (e.g., 2-arg hypercall clobbers %ebx,%ecx)
 */

#if __XEN_INTERFACE_VERSION__ < 0x00030203
/*
 * Legacy hypercall interface:
 * As above, except the entry sequence to the hypervisor is:
 *  mov $hypercall-number*32,%eax ; int $0x82
 */
#define TRAP_INSTR "int $0x82"
#endif

/* Structural guest handles introduced in 0x00030201. */
#if __XEN_INTERFACE_VERSION__ >= 0x00030201
#define __DEFINE_XEN_GUEST_HANDLE(name, type) \
    typedef struct { type *p; } __guest_handle_ ## name
#else
#define __DEFINE_XEN_GUEST_HANDLE(name, type) \
    typedef type * __guest_handle_ ## name
#endif

#define DEFINE_XEN_GUEST_HANDLE(name)   __DEFINE_XEN_GUEST_HANDLE(name, name)
#define XEN_GUEST_HANDLE(name)          __guest_handle_ ## name
#define set_xen_guest_handle(hnd, val)  do { (hnd).p = val; } while (0)
#ifdef __XEN_TOOLS__
#define get_xen_guest_handle(val, hnd)  do { val = (hnd).p; } while (0)
#endif

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

typedef unsigned long xen_pfn_t;
DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
#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

/*
 * 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
#define __MACH2PHYS_VIRT_START  0xF5800000
#define __MACH2PHYS_VIRT_END    0xF6800000
#else
#define __HYPERVISOR_VIRT_START 0xFC000000
#define __MACH2PHYS_VIRT_START  0xFC000000
#define __MACH2PHYS_VIRT_END    0xFC400000
#endif

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

#define MACH2PHYS_VIRT_START  mk_unsigned_long(__MACH2PHYS_VIRT_START)
#define MACH2PHYS_VIRT_END    mk_unsigned_long(__MACH2PHYS_VIRT_END)
#define MACH2PHYS_NR_ENTRIES  ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>2)
#ifndef machine_to_phys_mapping
#define machine_to_phys_mapping ((unsigned long *)MACH2PHYS_VIRT_START)
#endif

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

#ifndef __ASSEMBLY__

typedef unsigned long xen_ulong_t;

/*
 * 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                                   */
};
typedef struct trap_info trap_info_t;
DEFINE_XEN_GUEST_HANDLE(trap_info_t);

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;
};
typedef struct cpu_user_regs cpu_user_regs_t;
DEFINE_XEN_GUEST_HANDLE(cpu_user_regs_t);

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)
#define _VGCF_i387_valid               0
#define VGCF_i387_valid                (1<<_VGCF_i387_valid)
#define _VGCF_hvm_guest                1
#define VGCF_hvm_guest                 (1<<_VGCF_hvm_guest)
#define _VGCF_in_kernel                2
#define VGCF_in_kernel                 (1<<_VGCF_in_kernel)
#define _VGCF_failsafe_disables_events 3
#define VGCF_failsafe_disables_events  (1<<_VGCF_failsafe_disables_events)
    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 */
};
typedef struct vcpu_guest_context vcpu_guest_context_t;
DEFINE_XEN_GUEST_HANDLE(vcpu_guest_context_t);

/*
 * Page-directory addresses above 4GB do not fit into architectural %cr3.
 * When accessing %cr3, or equivalent field in vcpu_guest_context, guests
 * must use the following accessor macros to pack/unpack valid MFNs.
 */
#define xen_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20))
#define xen_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20))

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. */
    xen_pfn_t     pfn_to_mfn_frame_list_list;
    unsigned long nmi_reason;
    uint64_t pad[32];
};
typedef struct arch_shared_info arch_shared_info_t;

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

struct xen_callback {
    unsigned long cs;
    unsigned long eip;
};
typedef struct xen_callback xen_callback_t;

#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

/*
 * Local variables:
 * mode: C
 * c-set-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */