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memory: Move AddressSpaceDispatch from AddressSpace to FlatView

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As we are going to share FlatView's between AddressSpace's,
and AddressSpaceDispatch is a structure to perform quick lookup
in FlatView, this moves ASD to FlatView.

After previosly open coded ASD rendering, we can also remove
as->next_dispatch as the new FlatView pointer is stored
on a stack and set to an AS atomically.

flatview_destroy() is executed under RCU instead of
address_space_dispatch_free() now.

This makes mem_begin/mem_commit to work with ASD and mem_add with FV
as later on mem_add will be taking FV as an argument anyway.

This should cause no behavioural change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Message-Id: <20170921085110.25598-5-aik@ozlabs.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Alexey Kardashevskiy 2017-09-21 18:50:56 +10:00 committed by Paolo Bonzini
parent cc94cd6d36
commit 66a6df1dc6
4 changed files with 42 additions and 44 deletions
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41
exec.c
View File

@ -187,8 +187,6 @@ typedef struct PhysPageMap {
} PhysPageMap;
struct AddressSpaceDispatch {
struct rcu_head rcu;
MemoryRegionSection *mru_section;
/* This is a multi-level map on the physical address space.
* The bottom level has pointers to MemoryRegionSections.
@ -485,7 +483,7 @@ static MemoryRegionSection address_space_do_translate(AddressSpace *as,
IOMMUMemoryRegionClass *imrc;
for (;;) {
AddressSpaceDispatch *d = atomic_rcu_read(&as->dispatch);
AddressSpaceDispatch *d = address_space_to_dispatch(as);
section = address_space_translate_internal(d, addr, &addr, plen, is_mmio);
iommu_mr = memory_region_get_iommu(section->mr);
@ -1222,7 +1220,7 @@ hwaddr memory_region_section_get_iotlb(CPUState *cpu,
} else {
AddressSpaceDispatch *d;
d = atomic_rcu_read(&section->address_space->dispatch);
d = address_space_to_dispatch(section->address_space);
iotlb = section - d->map.sections;
iotlb += xlat;
}
@ -1347,9 +1345,9 @@ static void register_multipage(AddressSpaceDispatch *d,
phys_page_set(d, start_addr >> TARGET_PAGE_BITS, num_pages, section_index);
}
void mem_add(AddressSpace *as, MemoryRegionSection *section)
void mem_add(AddressSpace *as, FlatView *fv, MemoryRegionSection *section)
{
AddressSpaceDispatch *d = as->next_dispatch;
AddressSpaceDispatch *d = flatview_to_dispatch(fv);
MemoryRegionSection now = *section, remain = *section;
Int128 page_size = int128_make64(TARGET_PAGE_SIZE);
@ -2672,7 +2670,7 @@ static void io_mem_init(void)
NULL, UINT64_MAX);
}
void mem_begin(AddressSpace *as)
AddressSpaceDispatch *mem_begin(AddressSpace *as)
{
AddressSpaceDispatch *d = g_new0(AddressSpaceDispatch, 1);
uint16_t n;
@ -2688,26 +2686,19 @@ void mem_begin(AddressSpace *as)
d->phys_map = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .skip = 1 };
d->as = as;
as->next_dispatch = d;
return d;
}
static void address_space_dispatch_free(AddressSpaceDispatch *d)
void address_space_dispatch_free(AddressSpaceDispatch *d)
{
phys_sections_free(&d->map);
g_free(d);
}
void mem_commit(AddressSpace *as)
void mem_commit(AddressSpaceDispatch *d)
{
AddressSpaceDispatch *cur = as->dispatch;
AddressSpaceDispatch *next = as->next_dispatch;
phys_page_compact_all(next, next->map.nodes_nb);
atomic_rcu_set(&as->dispatch, next);
if (cur) {
call_rcu(cur, address_space_dispatch_free, rcu);
}
phys_page_compact_all(d, d->map.nodes_nb);
}
static void tcg_commit(MemoryListener *listener)
@ -2723,21 +2714,11 @@ static void tcg_commit(MemoryListener *listener)
* We reload the dispatch pointer now because cpu_reloading_memory_map()
* may have split the RCU critical section.
*/
d = atomic_rcu_read(&cpuas->as->dispatch);
d = address_space_to_dispatch(cpuas->as);
atomic_rcu_set(&cpuas->memory_dispatch, d);
tlb_flush(cpuas->cpu);
}
void address_space_destroy_dispatch(AddressSpace *as)
{
AddressSpaceDispatch *d = as->dispatch;
atomic_rcu_set(&as->dispatch, NULL);
if (d) {
call_rcu(d, address_space_dispatch_free, rcu);
}
}
static void memory_map_init(void)
{
system_memory = g_malloc(sizeof(*system_memory));

12
include/exec/memory-internal.h
View File

@ -22,16 +22,18 @@
#ifndef CONFIG_USER_ONLY
typedef struct AddressSpaceDispatch AddressSpaceDispatch;
void address_space_destroy_dispatch(AddressSpace *as);
extern const MemoryRegionOps unassigned_mem_ops;
bool memory_region_access_valid(MemoryRegion *mr, hwaddr addr,
unsigned size, bool is_write);
void mem_add(AddressSpace *as, MemoryRegionSection *section);
void mem_begin(AddressSpace *as);
void mem_commit(AddressSpace *as);
void mem_add(AddressSpace *as, FlatView *fv, MemoryRegionSection *section);
AddressSpaceDispatch *mem_begin(AddressSpace *as);
void mem_commit(AddressSpaceDispatch *d);
AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as);
AddressSpaceDispatch *flatview_to_dispatch(FlatView *fv);
void address_space_dispatch_free(AddressSpaceDispatch *d);
#endif
#endif

2
include/exec/memory.h
View File

@ -316,8 +316,6 @@ struct AddressSpace {
int ioeventfd_nb;
struct MemoryRegionIoeventfd *ioeventfds;
struct AddressSpaceDispatch *dispatch;
struct AddressSpaceDispatch *next_dispatch;
QTAILQ_HEAD(memory_listeners_as, MemoryListener) listeners;
QTAILQ_ENTRY(AddressSpace) address_spaces_link;
};

31
memory.c
View File

@ -229,6 +229,7 @@ struct FlatView {
FlatRange *ranges;
unsigned nr;
unsigned nr_allocated;
struct AddressSpaceDispatch *dispatch;
};
typedef struct AddressSpaceOps AddressSpaceOps;
@ -289,6 +290,9 @@ static void flatview_destroy(FlatView *view)
{
int i;
if (view->dispatch) {
address_space_dispatch_free(view->dispatch);
}
for (i = 0; i < view->nr; i++) {
memory_region_unref(view->ranges[i].mr);
}
@ -304,10 +308,25 @@ static bool flatview_ref(FlatView *view)
static void flatview_unref(FlatView *view)
{
if (atomic_fetch_dec(&view->ref) == 1) {
flatview_destroy(view);
call_rcu(view, flatview_destroy, rcu);
}
}
static FlatView *address_space_to_flatview(AddressSpace *as)
{
return atomic_rcu_read(&as->current_map);
}
AddressSpaceDispatch *flatview_to_dispatch(FlatView *fv)
{
return fv->dispatch;
}
AddressSpaceDispatch *address_space_to_dispatch(AddressSpace *as)
{
return flatview_to_dispatch(address_space_to_flatview(as));
}
static bool can_merge(FlatRange *r1, FlatRange *r2)
{
return int128_eq(addrrange_end(r1->addr), r2->addr.start)
@ -891,13 +910,13 @@ static void address_space_update_topology(AddressSpace *as)
FlatView *new_view = generate_memory_topology(as->root);
int i;
mem_begin(as);
new_view->dispatch = mem_begin(as);
for (i = 0; i < new_view->nr; i++) {
MemoryRegionSection mrs =
section_from_flat_range(&new_view->ranges[i], as);
mem_add(as, &mrs);
mem_add(as, new_view, &mrs);
}
mem_commit(as);
mem_commit(new_view->dispatch);
if (!QTAILQ_EMPTY(&as->listeners)) {
address_space_update_topology_pass(as, old_view, new_view, false);
@ -906,7 +925,7 @@ static void address_space_update_topology(AddressSpace *as)
/* Writes are protected by the BQL. */
atomic_rcu_set(&as->current_map, new_view);
call_rcu(old_view, flatview_unref, rcu);
flatview_unref(old_view);
/* Note that all the old MemoryRegions are still alive up to this
* point. This relieves most MemoryListeners from the need to
@ -2636,7 +2655,6 @@ void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
QTAILQ_INIT(&as->listeners);
QTAILQ_INSERT_TAIL(&address_spaces, as, address_spaces_link);
as->name = g_strdup(name ? name : "anonymous");
as->dispatch = NULL;
memory_region_update_pending |= root->enabled;
memory_region_transaction_commit();
}
@ -2645,7 +2663,6 @@ static void do_address_space_destroy(AddressSpace *as)
{
bool do_free = as->malloced;
address_space_destroy_dispatch(as);
assert(QTAILQ_EMPTY(&as->listeners));
flatview_unref(as->current_map);