Commit a9a0c06d authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

memory: use a new FlatView pointer on every topology update 



This is the first step towards converting as->current_map to
RCU-style updates, where the FlatView updates run concurrently
with uses of an old FlatView.

Reviewed-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 99e86347

memory.c

+18 −16
Original line number Diff line number Diff line
@@ -276,6 +276,7 @@ static void flatview_destroy(FlatView *view) 
        memory_region_unref(view->ranges[i].mr);

    }

    g_free(view->ranges);

    g_free(view);

}



static bool can_merge(FlatRange *r1, FlatRange *r2)
@@ -512,17 +513,18 @@ static void render_memory_region(FlatView *view, 
}



/* Render a memory topology into a list of disjoint absolute ranges. */

static FlatView generate_memory_topology(MemoryRegion *mr)

static FlatView *generate_memory_topology(MemoryRegion *mr)

{

    FlatView view;

    FlatView *view;



    flatview_init(&view);

    view = g_new(FlatView, 1);

    flatview_init(view);



    if (mr) {

        render_memory_region(&view, mr, int128_zero(),

        render_memory_region(view, mr, int128_zero(),

                             addrrange_make(int128_zero(), int128_2_64()), false);

    }

    flatview_simplify(&view);

    flatview_simplify(view);



    return view;

}
@@ -610,8 +612,8 @@ static void address_space_update_ioeventfds(AddressSpace *as) 
}



static void address_space_update_topology_pass(AddressSpace *as,

                                               FlatView old_view,

                                               FlatView new_view,

                                               const FlatView *old_view,

                                               const FlatView *new_view,

                                               bool adding)

{

    unsigned iold, inew;
@@ -621,14 +623,14 @@ static void address_space_update_topology_pass(AddressSpace *as, 
     * Kill ranges in the old map, and instantiate ranges in the new map.

     */

    iold = inew = 0;

    while (iold < old_view.nr || inew < new_view.nr) {

        if (iold < old_view.nr) {

            frold = &old_view.ranges[iold];

    while (iold < old_view->nr || inew < new_view->nr) {

        if (iold < old_view->nr) {

            frold = &old_view->ranges[iold];

        } else {

            frold = NULL;

        }

        if (inew < new_view.nr) {

            frnew = &new_view.ranges[inew];

        if (inew < new_view->nr) {

            frnew = &new_view->ranges[inew];

        } else {

            frnew = NULL;

        }
@@ -674,14 +676,14 @@ static void address_space_update_topology_pass(AddressSpace *as, 


static void address_space_update_topology(AddressSpace *as)

{

    FlatView old_view = *as->current_map;

    FlatView new_view = generate_memory_topology(as->root);

    FlatView *old_view = as->current_map;

    FlatView *new_view = generate_memory_topology(as->root);



    address_space_update_topology_pass(as, old_view, new_view, false);

    address_space_update_topology_pass(as, old_view, new_view, true);



    *as->current_map = new_view;

    flatview_destroy(&old_view);

    as->current_map = new_view;

    flatview_destroy(old_view);

    address_space_update_ioeventfds(as);

}