root/include/linux/lguest.h

INCLUDED FROM

/* 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:032 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;

        /* 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;
        /* Page where the top-level pagetable is */
        unsigned long pgdir;

/* 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 */