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xen: Get memory map from hypervisor for PVH

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Retrieve the memory map from the hypervisor and normalize it to contain
no overlapping entries and to be sorted by address.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Hans van Kranenburg <hans@knorrie.org>
This commit is contained in:
Juergen Gross 2018-12-07 13:11:40 +01:00 committed by Vincent Batts
parent d0c68baa5b
commit ad37d8a89e
1 changed files with 94 additions and 0 deletions
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94
grub-core/kern/i386/xen/pvh.c
View file

@ -24,7 +24,12 @@
#include <grub/i386/io.h>
#include <grub/xen.h>
#include <xen/hvm/start_info.h>
#include <grub/i386/linux.h>
#include <grub/machine/kernel.h>
#include <grub/machine/memory.h>
#include <xen/memory.h>
#define XEN_MEMORY_MAP_SIZE 128
grub_uint64_t grub_rsdp_addr;
@ -32,6 +37,8 @@ static char hypercall_page[GRUB_XEN_PAGE_SIZE]
__attribute__ ((aligned (GRUB_XEN_PAGE_SIZE)));
static grub_uint32_t xen_cpuid_base;
static struct grub_e820_mmap_entry map[XEN_MEMORY_MAP_SIZE];
static unsigned int nr_map_entries;
static void
grub_xen_cons_msg (const char *msg)
@ -104,11 +111,98 @@ grub_xen_hypercall (grub_uint32_t callno, grub_uint32_t a0,
return res;
}
static void
grub_xen_sort_mmap (void)
{
grub_uint64_t from, to;
unsigned int i;
struct grub_e820_mmap_entry tmp;
/* Align map entries to page boundaries. */
for (i = 0; i < nr_map_entries; i++)
{
from = map[i].addr;
to = from + map[i].len;
if (map[i].type == GRUB_MEMORY_AVAILABLE)
{
from = ALIGN_UP (from, GRUB_XEN_PAGE_SIZE);
to = ALIGN_DOWN (to, GRUB_XEN_PAGE_SIZE);
}
else
{
from = ALIGN_DOWN (from, GRUB_XEN_PAGE_SIZE);
to = ALIGN_UP (to, GRUB_XEN_PAGE_SIZE);
}
map[i].addr = from;
map[i].len = to - from;
}
again:
/* Sort entries by start address. */
for (i = 1; i < nr_map_entries; i++)
{
if (map[i].addr >= map[i - 1].addr)
continue;
tmp = map[i];
map[i] = map[i - 1];
map[i - 1] = tmp;
i = 0;
}
/* Detect overlapping areas. */
for (i = 1; i < nr_map_entries; i++)
{
if (map[i].addr >= map[i - 1].addr + map[i - 1].len)
continue;
tmp = map[i - 1];
map[i - 1].len = map[i].addr - map[i - 1].addr;
if (map[i].addr + map[i].len >= tmp.addr + tmp.len)
continue;
if (nr_map_entries < ARRAY_SIZE (map))
{
map[nr_map_entries].addr = map[i].addr + map[i].len;
map[nr_map_entries].len = tmp.addr + tmp.len - map[nr_map_entries].addr;
map[nr_map_entries].type = tmp.type;
nr_map_entries++;
goto again;
}
}
/* Merge adjacent entries. */
for (i = 1; i < nr_map_entries; i++)
{
if (map[i].type == map[i - 1].type &&
map[i].addr == map[i - 1].addr + map[i - 1].len)
{
map[i - 1].len += map[i].len;
map[i] = map[nr_map_entries - 1];
nr_map_entries--;
goto again;
}
}
}
static void
grub_xen_get_mmap (void)
{
struct xen_memory_map memmap;
memmap.nr_entries = ARRAY_SIZE (map);
set_xen_guest_handle (memmap.buffer, map);
if (grub_xen_hypercall (__HYPERVISOR_memory_op, XENMEM_memory_map,
(grub_uint32_t) (&memmap), 0, 0, 0, 0))
grub_xen_panic ("Could not get memory map from Xen!\n");
nr_map_entries = memmap.nr_entries;
grub_xen_sort_mmap ();
}
void
grub_xen_setup_pvh (void)
{
grub_xen_cpuid_base ();
grub_xen_setup_hypercall_page ();
grub_xen_get_mmap ();
}
grub_err_t