Commit 6092666e authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

exec: remove cur_map 



cur_map is not used anymore; instead, each AddressSpaceDispatch
has its own nodes/sections pair.  The priorities of the
MemoryListeners, and in the future RCU, guarantee that the
nodes/sections are not freed while they are still in use.

(In fact, next_map itself is not needed except to free the data on the
next update).

To avoid incorrect use, replace cur_map with a temporary copy that
is only valid while the topology is being updated.  If you use it,
the name prev_map makes it clear that you're doing something weird.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 0475d94f

exec.c

+7 −5
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ typedef struct PhysPageMap { 
    MemoryRegionSection *sections;

} PhysPageMap;



static PhysPageMap cur_map;

static PhysPageMap *prev_map;

static PhysPageMap next_map;



#define PHYS_MAP_NODE_NIL (((uint16_t)~0) >> 1)
@@ -790,7 +790,7 @@ static void phys_section_destroy(MemoryRegion *mr) 
    }

}



static void phys_sections_clear(PhysPageMap *map)

static void phys_sections_free(PhysPageMap *map)

{

    while (map->sections_nb > 0) {

        MemoryRegionSection *section = &map->sections[--map->sections_nb];
@@ -798,6 +798,7 @@ static void phys_sections_clear(PhysPageMap *map) 
    }

    g_free(map->sections);

    g_free(map->nodes);

    g_free(map);

}



static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *section)
@@ -1731,6 +1732,9 @@ static void core_begin(MemoryListener *listener) 
{

    uint16_t n;



    prev_map = g_new(PhysPageMap, 1);

    *prev_map = next_map;



    memset(&next_map, 0, sizeof(next_map));

    n = dummy_section(&io_mem_unassigned);

    assert(n == PHYS_SECTION_UNASSIGNED);
@@ -1747,9 +1751,7 @@ static void core_begin(MemoryListener *listener) 
 */

static void core_commit(MemoryListener *listener)

{

    PhysPageMap info = cur_map;

    cur_map = next_map;

    phys_sections_clear(&info);

    phys_sections_free(prev_map);

}



static void tcg_commit(MemoryListener *listener)