/******************************************************************************
 * xg_private.c
 * 
 * Helper functions for the rest of the library.
 */

#include <stdlib.h>
#include <unistd.h>
#include <zlib.h>

#include "xg_private.h"

char *xc_read_kernel_image(const char *filename, unsigned long *size)
{
    int kernel_fd = -1;
    gzFile kernel_gfd = NULL;
    char *image = NULL;
    unsigned int bytes;

    if ( (kernel_fd = open(filename, O_RDONLY)) < 0 )
    {
        PERROR("Could not open kernel image");
        goto out;
    }

    if ( (*size = xc_get_filesz(kernel_fd)) == 0 )
    {
        PERROR("Could not read kernel image");
        goto out;
    }

    if ( (kernel_gfd = gzdopen(kernel_fd, "rb")) == NULL )
    {
        PERROR("Could not allocate decompression state for state file");
        goto out;
    }

    if ( (image = malloc(*size)) == NULL )
    {
        PERROR("Could not allocate memory for kernel image");
        goto out;
    }

    if ( (bytes = gzread(kernel_gfd, image, *size)) != *size )
    {
        PERROR("Error reading kernel image, could not"
               " read the whole image (%d != %ld).", bytes, *size);
        free(image);
        image = NULL;
    }

 out:
    if ( kernel_gfd != NULL )
        gzclose(kernel_gfd);
    else if ( kernel_fd >= 0 )
        close(kernel_fd);
    return image;
}

/*******************/

int pin_table(
    int xc_handle, unsigned int type, unsigned long mfn, domid_t dom)
{
    struct mmuext_op op;

    op.cmd = type;
    op.arg1.mfn = mfn;

    if ( xc_mmuext_op(xc_handle, &op, 1, dom) < 0 )
        return 1;

    return 0;
}

/* This is shared between save and restore, and may generally be useful. */
unsigned long csum_page (void * page)
{
    int i;
    unsigned long *p = page;
    unsigned long long sum=0;

    for ( i = 0; i < (PAGE_SIZE/sizeof(unsigned long)); i++ )
        sum += p[i];

    return sum ^ (sum>>32);
}