lguest.h

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/*
 * Things the lguest guest needs to know.  Note: like all lguest interfaces,
 * this is subject to wild and random change between versions.
 */
#ifndef _LINUX_LGUEST_H
#define _LINUX_LGUEST_H

#ifndef __ASSEMBLY__
#include <linux/time.h>
#include <asm/irq.h>
#include <asm/lguest_hcall.h>

#define LG_CLOCK_MIN_DELTA  100UL
#define LG_CLOCK_MAX_DELTA  ULONG_MAX

/*G:031
 * The second method of communicating with the Host is to via "struct
 * lguest_data".  Once the Guest's initialization hypercall tells the Host where
 * this is, the Guest and Host both publish information in it.
:*/
struct lguest_data {
    /*
     * 512 == enabled (same as eflags in normal hardware).  The Guest
     * changes interrupts so often that a hypercall is too slow.
     */
    unsigned int irq_enabled;
    /* Fine-grained interrupt disabling by the Guest */
    DECLARE_BITMAP(blocked_interrupts, LGUEST_IRQS);

    /*
     * The Host writes the virtual address of the last page fault here,
     * which saves the Guest a hypercall.  CR2 is the native register where
     * this address would normally be found.
     */
    unsigned long cr2;

    /* Wallclock time set by the Host. */
    struct timespec time;

    /*
     * Interrupt pending set by the Host.  The Guest should do a hypercall
     * if it re-enables interrupts and sees this set (to X86_EFLAGS_IF).
     */
    int irq_pending;

    /*
     * Async hypercall ring.  Instead of directly making hypercalls, we can
     * place them in here for processing the next time the Host wants.
     * This batching can be quite efficient.
     */

    /* 0xFF == done (set by Host), 0 == pending (set by Guest). */
    u8 hcall_status[LHCALL_RING_SIZE];
    /* The actual registers for the hypercalls. */
    struct hcall_args hcalls[LHCALL_RING_SIZE];

/* Fields initialized by the Host at boot: */
    /* Memory not to try to access */
    unsigned long reserve_mem;
    /* KHz for the TSC clock. */
    u32 tsc_khz;

/* Fields initialized by the Guest at boot: */
    /* Instruction range to suppress interrupts even if enabled */
    unsigned long noirq_start, noirq_end;
    /* Address above which page tables are all identical. */
    unsigned long kernel_address;
    /* The vector to try to use for system calls (0x40 or 0x80). */
    unsigned int syscall_vec;
};
extern struct lguest_data lguest_data;
#endif /* __ASSEMBLY__ */
#endif  /* _LINUX_LGUEST_H */