lguest.h

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#ifndef _ASM_X86_LGUEST_H
#define _ASM_X86_LGUEST_H

#define GDT_ENTRY_LGUEST_CS 10
#define GDT_ENTRY_LGUEST_DS 11
#define LGUEST_CS       (GDT_ENTRY_LGUEST_CS * 8)
#define LGUEST_DS       (GDT_ENTRY_LGUEST_DS * 8)

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

#define GUEST_PL 1

/* Every guest maps the core switcher code. */
#define SHARED_SWITCHER_PAGES \
    DIV_ROUND_UP(end_switcher_text - start_switcher_text, PAGE_SIZE)
/* Pages for switcher itself, then two pages per cpu */
#define TOTAL_SWITCHER_PAGES (SHARED_SWITCHER_PAGES + 2 * nr_cpu_ids)

/* We map at -4M (-2M for PAE) for ease of mapping (one PTE page). */
#ifdef CONFIG_X86_PAE
#define SWITCHER_ADDR 0xFFE00000
#else
#define SWITCHER_ADDR 0xFFC00000
#endif

/* Found in switcher.S */
extern unsigned long default_idt_entries[];

/* Declarations for definitions in lguest_guest.S */
extern char lguest_noirq_start[], lguest_noirq_end[];
extern const char lgstart_cli[], lgend_cli[];
extern const char lgstart_sti[], lgend_sti[];
extern const char lgstart_popf[], lgend_popf[];
extern const char lgstart_pushf[], lgend_pushf[];
extern const char lgstart_iret[], lgend_iret[];

extern void lguest_iret(void);
extern void lguest_init(void);

struct lguest_regs {
    /* Manually saved part. */
    unsigned long eax, ebx, ecx, edx;
    unsigned long esi, edi, ebp;
    unsigned long gs;
    unsigned long fs, ds, es;
    unsigned long trapnum, errcode;
    /* Trap pushed part */
    unsigned long eip;
    unsigned long cs;
    unsigned long eflags;
    unsigned long esp;
    unsigned long ss;
};

/* This is a guest-specific page (mapped ro) into the guest. */
struct lguest_ro_state {
    /* Host information we need to restore when we switch back. */
    u32 host_cr3;
    struct desc_ptr host_idt_desc;
    struct desc_ptr host_gdt_desc;
    u32 host_sp;

    /* Fields which are used when guest is running. */
    struct desc_ptr guest_idt_desc;
    struct desc_ptr guest_gdt_desc;
    struct x86_hw_tss guest_tss;
    struct desc_struct guest_idt[IDT_ENTRIES];
    struct desc_struct guest_gdt[GDT_ENTRIES];
};

struct lg_cpu_arch {
    /* The GDT entries copied into lguest_ro_state when running. */
    struct desc_struct gdt[GDT_ENTRIES];

    /* The IDT entries: some copied into lguest_ro_state when running. */
    struct desc_struct idt[IDT_ENTRIES];

    /* The address of the last guest-visible pagefault (ie. cr2). */
    unsigned long last_pagefault;
};

static inline void lguest_set_ts(void)
{
    u32 cr0;

    cr0 = read_cr0();
    if (!(cr0 & 8))
        write_cr0(cr0 | 8);
}

/* Full 4G segment descriptors, suitable for CS and DS. */
#define FULL_EXEC_SEGMENT \
    ((struct desc_struct)GDT_ENTRY_INIT(0xc09b, 0, 0xfffff))
#define FULL_SEGMENT ((struct desc_struct)GDT_ENTRY_INIT(0xc093, 0, 0xfffff))

#endif /* __ASSEMBLY__ */

#endif /* _ASM_X86_LGUEST_H */