exec: separate sections and nodes per address space

Every address space has its own nodes and sections, but
it uses the same global arrays of nodes/section.

This limits the number of devices that can be attached
to the guest to 20-30 devices. It happens because:
 - The sections array is limited to 2^12 entries.
 - The main memory has at least 100 sections.
 - Each device address space is actually an alias to
   main memory, multiplying its number of nodes/sections.

Remove the limitation by using separate arrays of
nodes and sections for each address space.

Signed-off-by: Marcel Apfelbaum <marcel.a@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Marcel Apfelbaum 2013-12-01 14:02:23 +02:00 committed by Michael S. Tsirkin
parent 6307d974f9
commit 53cb28cbfe
1 changed files with 66 additions and 89 deletions

155
exec.c
View File

@ -103,13 +103,21 @@ struct PhysPageEntry {
typedef PhysPageEntry Node[P_L2_SIZE];
typedef struct PhysPageMap {
unsigned sections_nb;
unsigned sections_nb_alloc;
unsigned nodes_nb;
unsigned nodes_nb_alloc;
Node *nodes;
MemoryRegionSection *sections;
} PhysPageMap;
struct AddressSpaceDispatch {
/* This is a multi-level map on the physical address space.
* The bottom level has pointers to MemoryRegionSections.
*/
PhysPageEntry phys_map;
Node *nodes;
MemoryRegionSection *sections;
PhysPageMap map;
AddressSpace *as;
};
@ -126,18 +134,6 @@ typedef struct subpage_t {
#define PHYS_SECTION_ROM 2
#define PHYS_SECTION_WATCH 3
typedef struct PhysPageMap {
unsigned sections_nb;
unsigned sections_nb_alloc;
unsigned nodes_nb;
unsigned nodes_nb_alloc;
Node *nodes;
MemoryRegionSection *sections;
} PhysPageMap;
static PhysPageMap *prev_map;
static PhysPageMap next_map;
static void io_mem_init(void);
static void memory_map_init(void);
@ -146,35 +142,32 @@ static MemoryRegion io_mem_watch;
#if !defined(CONFIG_USER_ONLY)
static void phys_map_node_reserve(unsigned nodes)
static void phys_map_node_reserve(PhysPageMap *map, unsigned nodes)
{
if (next_map.nodes_nb + nodes > next_map.nodes_nb_alloc) {
next_map.nodes_nb_alloc = MAX(next_map.nodes_nb_alloc * 2,
16);
next_map.nodes_nb_alloc = MAX(next_map.nodes_nb_alloc,
next_map.nodes_nb + nodes);
next_map.nodes = g_renew(Node, next_map.nodes,
next_map.nodes_nb_alloc);
if (map->nodes_nb + nodes > map->nodes_nb_alloc) {
map->nodes_nb_alloc = MAX(map->nodes_nb_alloc * 2, 16);
map->nodes_nb_alloc = MAX(map->nodes_nb_alloc, map->nodes_nb + nodes);
map->nodes = g_renew(Node, map->nodes, map->nodes_nb_alloc);
}
}
static uint32_t phys_map_node_alloc(void)
static uint32_t phys_map_node_alloc(PhysPageMap *map)
{
unsigned i;
uint32_t ret;
ret = next_map.nodes_nb++;
ret = map->nodes_nb++;
assert(ret != PHYS_MAP_NODE_NIL);
assert(ret != next_map.nodes_nb_alloc);
assert(ret != map->nodes_nb_alloc);
for (i = 0; i < P_L2_SIZE; ++i) {
next_map.nodes[ret][i].skip = 1;
next_map.nodes[ret][i].ptr = PHYS_MAP_NODE_NIL;
map->nodes[ret][i].skip = 1;
map->nodes[ret][i].ptr = PHYS_MAP_NODE_NIL;
}
return ret;
}
static void phys_page_set_level(PhysPageEntry *lp, hwaddr *index,
hwaddr *nb, uint16_t leaf,
static void phys_page_set_level(PhysPageMap *map, PhysPageEntry *lp,
hwaddr *index, hwaddr *nb, uint16_t leaf,
int level)
{
PhysPageEntry *p;
@ -182,8 +175,8 @@ static void phys_page_set_level(PhysPageEntry *lp, hwaddr *index,
hwaddr step = (hwaddr)1 << (level * P_L2_BITS);
if (lp->skip && lp->ptr == PHYS_MAP_NODE_NIL) {
lp->ptr = phys_map_node_alloc();
p = next_map.nodes[lp->ptr];
lp->ptr = phys_map_node_alloc(map);
p = map->nodes[lp->ptr];
if (level == 0) {
for (i = 0; i < P_L2_SIZE; i++) {
p[i].skip = 0;
@ -191,7 +184,7 @@ static void phys_page_set_level(PhysPageEntry *lp, hwaddr *index,
}
}
} else {
p = next_map.nodes[lp->ptr];
p = map->nodes[lp->ptr];
}
lp = &p[(*index >> (level * P_L2_BITS)) & (P_L2_SIZE - 1)];
@ -202,7 +195,7 @@ static void phys_page_set_level(PhysPageEntry *lp, hwaddr *index,
*index += step;
*nb -= step;
} else {
phys_page_set_level(lp, index, nb, leaf, level - 1);
phys_page_set_level(map, lp, index, nb, leaf, level - 1);
}
++lp;
}
@ -213,9 +206,9 @@ static void phys_page_set(AddressSpaceDispatch *d,
uint16_t leaf)
{
/* Wildly overreserve - it doesn't matter much. */
phys_map_node_reserve(3 * P_L2_LEVELS);
phys_map_node_reserve(&d->map, 3 * P_L2_LEVELS);
phys_page_set_level(&d->phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
phys_page_set_level(&d->map, &d->phys_map, &index, &nb, leaf, P_L2_LEVELS - 1);
}
/* Compact a non leaf page entry. Simply detect that the entry has a single child,
@ -276,7 +269,7 @@ static void phys_page_compact_all(AddressSpaceDispatch *d, int nodes_nb)
DECLARE_BITMAP(compacted, nodes_nb);
if (d->phys_map.skip) {
phys_page_compact(&d->phys_map, d->nodes, compacted);
phys_page_compact(&d->phys_map, d->map.nodes, compacted);
}
}
@ -317,10 +310,10 @@ static MemoryRegionSection *address_space_lookup_region(AddressSpaceDispatch *d,
MemoryRegionSection *section;
subpage_t *subpage;
section = phys_page_find(d->phys_map, addr, d->nodes, d->sections);
section = phys_page_find(d->phys_map, addr, d->map.nodes, d->map.sections);
if (resolve_subpage && section->mr->subpage) {
subpage = container_of(section->mr, subpage_t, iomem);
section = &d->sections[subpage->sub_section[SUBPAGE_IDX(addr)]];
section = &d->map.sections[subpage->sub_section[SUBPAGE_IDX(addr)]];
}
return section;
}
@ -788,7 +781,7 @@ hwaddr memory_region_section_get_iotlb(CPUArchState *env,
iotlb |= PHYS_SECTION_ROM;
}
} else {
iotlb = section - address_space_memory.dispatch->sections;
iotlb = section - address_space_memory.dispatch->map.sections;
iotlb += xlat;
}
@ -827,23 +820,23 @@ void phys_mem_set_alloc(void *(*alloc)(size_t))
phys_mem_alloc = alloc;
}
static uint16_t phys_section_add(MemoryRegionSection *section)
static uint16_t phys_section_add(PhysPageMap *map,
MemoryRegionSection *section)
{
/* The physical section number is ORed with a page-aligned
* pointer to produce the iotlb entries. Thus it should
* never overflow into the page-aligned value.
*/
assert(next_map.sections_nb < TARGET_PAGE_SIZE);
assert(map->sections_nb < TARGET_PAGE_SIZE);
if (next_map.sections_nb == next_map.sections_nb_alloc) {
next_map.sections_nb_alloc = MAX(next_map.sections_nb_alloc * 2,
16);
next_map.sections = g_renew(MemoryRegionSection, next_map.sections,
next_map.sections_nb_alloc);
if (map->sections_nb == map->sections_nb_alloc) {
map->sections_nb_alloc = MAX(map->sections_nb_alloc * 2, 16);
map->sections = g_renew(MemoryRegionSection, map->sections,
map->sections_nb_alloc);
}
next_map.sections[next_map.sections_nb] = *section;
map->sections[map->sections_nb] = *section;
memory_region_ref(section->mr);
return next_map.sections_nb++;
return map->sections_nb++;
}
static void phys_section_destroy(MemoryRegion *mr)
@ -865,7 +858,6 @@ static void phys_sections_free(PhysPageMap *map)
}
g_free(map->sections);
g_free(map->nodes);
g_free(map);
}
static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *section)
@ -874,7 +866,7 @@ static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *secti
hwaddr base = section->offset_within_address_space
& TARGET_PAGE_MASK;
MemoryRegionSection *existing = phys_page_find(d->phys_map, base,
next_map.nodes, next_map.sections);
d->map.nodes, d->map.sections);
MemoryRegionSection subsection = {
.offset_within_address_space = base,
.size = int128_make64(TARGET_PAGE_SIZE),
@ -887,13 +879,14 @@ static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *secti
subpage = subpage_init(d->as, base);
subsection.mr = &subpage->iomem;
phys_page_set(d, base >> TARGET_PAGE_BITS, 1,
phys_section_add(&subsection));
phys_section_add(&d->map, &subsection));
} else {
subpage = container_of(existing->mr, subpage_t, iomem);
}
start = section->offset_within_address_space & ~TARGET_PAGE_MASK;
end = start + int128_get64(section->size) - 1;
subpage_register(subpage, start, end, phys_section_add(section));
subpage_register(subpage, start, end,
phys_section_add(&d->map, section));
}
@ -901,7 +894,7 @@ static void register_multipage(AddressSpaceDispatch *d,
MemoryRegionSection *section)
{
hwaddr start_addr = section->offset_within_address_space;
uint16_t section_index = phys_section_add(section);
uint16_t section_index = phys_section_add(&d->map, section);
uint64_t num_pages = int128_get64(int128_rshift(section->size,
TARGET_PAGE_BITS));
@ -1720,7 +1713,7 @@ static subpage_t *subpage_init(AddressSpace *as, hwaddr base)
return mmio;
}
static uint16_t dummy_section(MemoryRegion *mr)
static uint16_t dummy_section(PhysPageMap *map, MemoryRegion *mr)
{
MemoryRegionSection section = {
.mr = mr,
@ -1729,12 +1722,13 @@ static uint16_t dummy_section(MemoryRegion *mr)
.size = int128_2_64(),
};
return phys_section_add(&section);
return phys_section_add(map, &section);
}
MemoryRegion *iotlb_to_region(hwaddr index)
{
return address_space_memory.dispatch->sections[index & ~TARGET_PAGE_MASK].mr;
return address_space_memory.dispatch->map.sections[
index & ~TARGET_PAGE_MASK].mr;
}
static void io_mem_init(void)
@ -1751,7 +1745,17 @@ static void io_mem_init(void)
static void mem_begin(MemoryListener *listener)
{
AddressSpace *as = container_of(listener, AddressSpace, dispatch_listener);
AddressSpaceDispatch *d = g_new(AddressSpaceDispatch, 1);
AddressSpaceDispatch *d = g_new0(AddressSpaceDispatch, 1);
uint16_t n;
n = dummy_section(&d->map, &io_mem_unassigned);
assert(n == PHYS_SECTION_UNASSIGNED);
n = dummy_section(&d->map, &io_mem_notdirty);
assert(n == PHYS_SECTION_NOTDIRTY);
n = dummy_section(&d->map, &io_mem_rom);
assert(n == PHYS_SECTION_ROM);
n = dummy_section(&d->map, &io_mem_watch);
assert(n == PHYS_SECTION_WATCH);
d->phys_map = (PhysPageEntry) { .ptr = PHYS_MAP_NODE_NIL, .skip = 1 };
d->as = as;
@ -1764,39 +1768,14 @@ static void mem_commit(MemoryListener *listener)
AddressSpaceDispatch *cur = as->dispatch;
AddressSpaceDispatch *next = as->next_dispatch;
next->nodes = next_map.nodes;
next->sections = next_map.sections;
phys_page_compact_all(next, next_map.nodes_nb);
phys_page_compact_all(next, next->map.nodes_nb);
as->dispatch = next;
g_free(cur);
}
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);
n = dummy_section(&io_mem_notdirty);
assert(n == PHYS_SECTION_NOTDIRTY);
n = dummy_section(&io_mem_rom);
assert(n == PHYS_SECTION_ROM);
n = dummy_section(&io_mem_watch);
assert(n == PHYS_SECTION_WATCH);
}
/* This listener's commit run after the other AddressSpaceDispatch listeners'.
* All AddressSpaceDispatch instances have switched to the next map.
*/
static void core_commit(MemoryListener *listener)
{
phys_sections_free(prev_map);
if (cur) {
phys_sections_free(&cur->map);
g_free(cur);
}
}
static void tcg_commit(MemoryListener *listener)
@ -1824,8 +1803,6 @@ static void core_log_global_stop(MemoryListener *listener)
}
static MemoryListener core_memory_listener = {
.begin = core_begin,
.commit = core_commit,
.log_global_start = core_log_global_start,
.log_global_stop = core_log_global_stop,
.priority = 1,