libqos: Convert malloc-pc allocator to a generic allocator

The allocator in malloc-pc has been extracted, so it can be used in every arch.
This operation showed that both the alloc and free functions can be also
generic.
Because of this, the QGuestAllocator has been removed from is function to wrap
the alloc and free function, and now just contains the allocator parameters.
As a result, only the allocator initalizer and unitializer are arch dependent.

Signed-off-by: Marc Marí <marc.mari.barcelo@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 270 insertions, 0 deletions

diff --git a/tests/libqos/malloc.c b/tests/libqos/malloc.c
new file mode 100644
index 0000000000..5debf18497
--- /dev/null
+++ b/tests/libqos/malloc.c
@@ -0,0 +1,270 @@
+/*
+ * 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 "libqos/malloc.h"
+#include "qemu-common.h"
+#include <stdio.h>
+#include <inttypes.h>
+#include <glib.h>
+
+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 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);
+}
+
+MemBlock *mlist_new(uint64_t addr, uint64_t size)
+{
+    MemBlock *block;
+
+    if (!size) {
+        return NULL;
+    }
+    block = g_malloc0(sizeof(MemBlock));
+
+    block->addr = addr;
+    block->size = size;
+
+    return block;
+}
+
+/*
+ * 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);
+}
+
+uint64_t guest_alloc(QGuestAllocator *allocator, size_t size)
+{
+    uint64_t rsize = size;
+    uint64_t naddr;
+
+    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)
+{
+    mlist_free(allocator, addr);
+    if (allocator->opts & ALLOC_PARANOID) {
+        mlist_check(allocator);
+    }
+}