qemu/tests/libqos/malloc.c

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/*
* libqos malloc support
*
* Copyright (c) 2014
*
* Author:
* John Snow <jsnow@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "libqos/malloc.h"
#include "qemu-common.h"
#include "qemu/host-utils.h"
typedef QTAILQ_HEAD(MemList, MemBlock) MemList;
typedef struct MemBlock {
QTAILQ_ENTRY(MemBlock) MLIST_ENTNAME;
uint64_t size;
uint64_t addr;
} MemBlock;
struct QGuestAllocator {
QAllocOpts opts;
uint64_t start;
uint64_t end;
uint32_t page_size;
MemList *used;
MemList *free;
};
#define DEFAULT_PAGE_SIZE 4096
static void mlist_delete(MemList *list, MemBlock *node)
{
g_assert(list && node);
QTAILQ_REMOVE(list, node, MLIST_ENTNAME);
g_free(node);
}
static MemBlock *mlist_find_key(MemList *head, uint64_t addr)
{
MemBlock *node;
QTAILQ_FOREACH(node, head, MLIST_ENTNAME) {
if (node->addr == addr) {
return node;
}
}
return NULL;
}
static MemBlock *mlist_find_space(MemList *head, uint64_t size)
{
MemBlock *node;
QTAILQ_FOREACH(node, head, MLIST_ENTNAME) {
if (node->size >= size) {
return node;
}
}
return NULL;
}
static MemBlock *mlist_sort_insert(MemList *head, MemBlock *insr)
{
MemBlock *node;
g_assert(head && insr);
QTAILQ_FOREACH(node, head, MLIST_ENTNAME) {
if (insr->addr < node->addr) {
QTAILQ_INSERT_BEFORE(node, insr, MLIST_ENTNAME);
return insr;
}
}
QTAILQ_INSERT_TAIL(head, insr, MLIST_ENTNAME);
return insr;
}
static inline uint64_t mlist_boundary(MemBlock *node)
{
return node->size + node->addr;
}
static MemBlock *mlist_join(MemList *head, MemBlock *left, MemBlock *right)
{
g_assert(head && left && right);
left->size += right->size;
mlist_delete(head, right);
return left;
}
static void mlist_coalesce(MemList *head, MemBlock *node)
{
g_assert(node);
MemBlock *left;
MemBlock *right;
char merge;
do {
merge = 0;
left = QTAILQ_PREV(node, MemList, MLIST_ENTNAME);
right = QTAILQ_NEXT(node, MLIST_ENTNAME);
/* clowns to the left of me */
if (left && mlist_boundary(left) == node->addr) {
node = mlist_join(head, left, node);
merge = 1;
}
/* jokers to the right */
if (right && mlist_boundary(node) == right->addr) {
node = mlist_join(head, node, right);
merge = 1;
}
} while (merge);
}
static MemBlock *mlist_new(uint64_t addr, uint64_t size)
{
MemBlock *block;
if (!size) {
return NULL;
}
block = g_new0(MemBlock, 1);
block->addr = addr;
block->size = size;
return block;
}
static uint64_t mlist_fulfill(QGuestAllocator *s, MemBlock *freenode,
uint64_t size)
{
uint64_t addr;
MemBlock *usednode;
g_assert(freenode);
g_assert_cmpint(freenode->size, >=, size);
addr = freenode->addr;
if (freenode->size == size) {
/* re-use this freenode as our used node */
QTAILQ_REMOVE(s->free, freenode, MLIST_ENTNAME);
usednode = freenode;
} else {
/* adjust the free node and create a new used node */
freenode->addr += size;
freenode->size -= size;
usednode = mlist_new(addr, size);
}
mlist_sort_insert(s->used, usednode);
return addr;
}
/* To assert the correctness of the list.
* Used only if ALLOC_PARANOID is set. */
static void mlist_check(QGuestAllocator *s)
{
MemBlock *node;
uint64_t addr = s->start > 0 ? s->start - 1 : 0;
uint64_t next = s->start;
QTAILQ_FOREACH(node, s->free, MLIST_ENTNAME) {
g_assert_cmpint(node->addr, >, addr);
g_assert_cmpint(node->addr, >=, next);
addr = node->addr;
next = node->addr + node->size;
}
addr = s->start > 0 ? s->start - 1 : 0;
next = s->start;
QTAILQ_FOREACH(node, s->used, MLIST_ENTNAME) {
g_assert_cmpint(node->addr, >, addr);
g_assert_cmpint(node->addr, >=, next);
addr = node->addr;
next = node->addr + node->size;
}
}
static uint64_t mlist_alloc(QGuestAllocator *s, uint64_t size)
{
MemBlock *node;
node = mlist_find_space(s->free, size);
if (!node) {
fprintf(stderr, "Out of guest memory.\n");
g_assert_not_reached();
}
return mlist_fulfill(s, node, size);
}
static void mlist_free(QGuestAllocator *s, uint64_t addr)
{
MemBlock *node;
if (addr == 0) {
return;
}
node = mlist_find_key(s->used, addr);
if (!node) {
fprintf(stderr, "Error: no record found for an allocation at "
"0x%016" PRIx64 ".\n",
addr);
g_assert_not_reached();
}
/* Rip it out of the used list and re-insert back into the free list. */
QTAILQ_REMOVE(s->used, node, MLIST_ENTNAME);
mlist_sort_insert(s->free, node);
mlist_coalesce(s->free, node);
}
/*
* Mostly for valgrind happiness, but it does offer
* a chokepoint for debugging guest memory leaks, too.
*/
void alloc_uninit(QGuestAllocator *allocator)
{
MemBlock *node;
MemBlock *tmp;
QAllocOpts mask;
/* Check for guest leaks, and destroy the list. */
QTAILQ_FOREACH_SAFE(node, allocator->used, MLIST_ENTNAME, tmp) {
if (allocator->opts & (ALLOC_LEAK_WARN | ALLOC_LEAK_ASSERT)) {
fprintf(stderr, "guest malloc leak @ 0x%016" PRIx64 "; "
"size 0x%016" PRIx64 ".\n",
node->addr, node->size);
}
if (allocator->opts & (ALLOC_LEAK_ASSERT)) {
g_assert_not_reached();
}
g_free(node);
}
/* If we have previously asserted that there are no leaks, then there
* should be only one node here with a specific address and size. */
mask = ALLOC_LEAK_ASSERT | ALLOC_PARANOID;
QTAILQ_FOREACH_SAFE(node, allocator->free, MLIST_ENTNAME, tmp) {
if ((allocator->opts & mask) == mask) {
if ((node->addr != allocator->start) ||
(node->size != allocator->end - allocator->start)) {
fprintf(stderr, "Free list is corrupted.\n");
g_assert_not_reached();
}
}
g_free(node);
}
g_free(allocator->used);
g_free(allocator->free);
g_free(allocator);
}
uint64_t guest_alloc(QGuestAllocator *allocator, size_t size)
{
uint64_t rsize = size;
uint64_t naddr;
if (!size) {
return 0;
}
rsize += (allocator->page_size - 1);
rsize &= -allocator->page_size;
g_assert_cmpint((allocator->start + rsize), <=, allocator->end);
g_assert_cmpint(rsize, >=, size);
naddr = mlist_alloc(allocator, rsize);
if (allocator->opts & ALLOC_PARANOID) {
mlist_check(allocator);
}
return naddr;
}
void guest_free(QGuestAllocator *allocator, uint64_t addr)
{
if (!addr) {
return;
}
mlist_free(allocator, addr);
if (allocator->opts & ALLOC_PARANOID) {
mlist_check(allocator);
}
}
QGuestAllocator *alloc_init(uint64_t start, uint64_t end)
{
QGuestAllocator *s = g_malloc0(sizeof(*s));
MemBlock *node;
s->start = start;
s->end = end;
s->used = g_new(MemList, 1);
s->free = g_new(MemList, 1);
QTAILQ_INIT(s->used);
QTAILQ_INIT(s->free);
node = mlist_new(s->start, s->end - s->start);
QTAILQ_INSERT_HEAD(s->free, node, MLIST_ENTNAME);
s->page_size = DEFAULT_PAGE_SIZE;
return s;
}
QGuestAllocator *alloc_init_flags(QAllocOpts opts,
uint64_t start, uint64_t end)
{
QGuestAllocator *s = alloc_init(start, end);
s->opts = opts;
return s;
}
void alloc_set_page_size(QGuestAllocator *allocator, size_t page_size)
{
/* Can't alter the page_size for an allocator in-use */
g_assert(QTAILQ_EMPTY(allocator->used));
g_assert(is_power_of_2(page_size));
allocator->page_size = page_size;
}
void alloc_set_flags(QGuestAllocator *allocator, QAllocOpts opts)
{
allocator->opts |= opts;
}
void migrate_allocator(QGuestAllocator *src,
QGuestAllocator *dst)
{
MemBlock *node, *tmp;
MemList *tmpused, *tmpfree;
/* The general memory layout should be equivalent,
* though opts can differ. */
g_assert_cmphex(src->start, ==, dst->start);
g_assert_cmphex(src->end, ==, dst->end);
/* Destroy (silently, regardless of options) the dest-list: */
QTAILQ_FOREACH_SAFE(node, dst->used, MLIST_ENTNAME, tmp) {
g_free(node);
}
QTAILQ_FOREACH_SAFE(node, dst->free, MLIST_ENTNAME, tmp) {
g_free(node);
}
tmpused = dst->used;
tmpfree = dst->free;
/* Inherit the lists of the source allocator: */
dst->used = src->used;
dst->free = src->free;
/* Source is now re-initialized, the source memory is 'invalid' now: */
src->used = tmpused;
src->free = tmpfree;
QTAILQ_INIT(src->used);
QTAILQ_INIT(src->free);
node = mlist_new(src->start, src->end - src->start);
QTAILQ_INSERT_HEAD(src->free, node, MLIST_ENTNAME);
return;
}