1.1 --- a/tools/libxc/xc_hvm_build.c	Wed Jan 16 15:55:57 2008 +0000
     1.2 +++ b/tools/libxc/xc_hvm_build.c	Thu Jan 17 12:59:10 2008 +0000
     1.3 @@ -77,13 +77,19 @@ static void build_e820map(void *e820_pag
     1.4      e820entry[nr_map].type = E820_RESERVED;
     1.5      nr_map++;
     1.6  
     1.7 -    /* Low RAM goes here. Remove 3 pages for ioreq, bufioreq, and xenstore. */
     1.8 +    /*
     1.9 +     * Low RAM goes here. Remove 4 pages for: ioreq, bufioreq, and xenstore.
    1.10 +     *  1. Guard page.
    1.11 +     *  2. Buffered ioreq.
    1.12 +     *  3. Xenstore.
    1.13 +     *  4. Normal ioreq.
    1.14 +     */
    1.15      e820entry[nr_map].addr = 0x100000;
    1.16 -    e820entry[nr_map].size = mem_size - 0x100000 - PAGE_SIZE * 3;
    1.17 +    e820entry[nr_map].size = mem_size - 0x100000 - PAGE_SIZE * 4;
    1.18      e820entry[nr_map].type = E820_RAM;
    1.19      nr_map++;
    1.20  
    1.21 -    /* Explicitly reserve space for special pages (ioreq and xenstore). */
    1.22 +    /* Explicitly reserve space for special pages. */
    1.23      e820entry[nr_map].addr = mem_size - PAGE_SIZE * 3;
    1.24      e820entry[nr_map].size = PAGE_SIZE * 3;
    1.25      e820entry[nr_map].type = E820_RESERVED;
    1.26 @@ -244,6 +250,15 @@ static int setup_guest(int xc_handle,
    1.27      else
    1.28          shared_page_nr = (v_end >> PAGE_SHIFT) - 1;
    1.29  
    1.30 +    /* Free the guard page that separates low RAM from special pages. */
    1.31 +    rc = xc_domain_memory_decrease_reservation(
    1.32 +            xc_handle, dom, 1, 0, &page_array[shared_page_nr-3]);
    1.33 +    if ( rc != 0 )
    1.34 +    {
    1.35 +        PERROR("Could not deallocate guard page for HVM guest.\n");
    1.36 +        goto error_out;
    1.37 +    }
    1.38 +
    1.39      /* Paranoia: clean pages. */
    1.40      if ( xc_clear_domain_page(xc_handle, dom, shared_page_nr) ||
    1.41           xc_clear_domain_page(xc_handle, dom, shared_page_nr-1) ||