tests/qtest/libqos/malloc.c - qemu - Git at Google

 /*
  * 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 "malloc.h"
 #include "qemu-common.h"
 #include "qemu/host-utils.h"

 typedef struct MemBlock {
     QTAILQ_ENTRY(MemBlock) MLIST_ENTNAME;
     uint64_t size;
     uint64_t addr;
 } MemBlock;

 #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, 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_destroy(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);
 }

 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);
     }
 }

 void alloc_init(QGuestAllocator *s, QAllocOpts opts,
                 uint64_t start, uint64_t end,
                 size_t page_size)
 {
     MemBlock *node;

     s->opts = opts;
     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 = 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;
 }
	/*
	* 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 "malloc.h"
	#include "qemu-common.h"
	#include "qemu/host-utils.h"

	typedef struct MemBlock {
	QTAILQ_ENTRY(MemBlock) MLIST_ENTNAME;
	uint64_t size;
	uint64_t addr;
	} MemBlock;

	#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, 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_destroy(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);
	}

	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);
	}
	}

	void alloc_init(QGuestAllocator *s, QAllocOpts opts,
	uint64_t start, uint64_t end,
	size_t page_size)
	{
	MemBlock *node;

	s->opts = opts;
	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 = 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;
	}