accel/tcg: Move remainder of page locking to tb-maint.c

The only thing that still touches PageDesc in translate-all.c
are some locking routines related to tb-maint.c which have not
yet been moved.  Do so now.

Move some code up in tb-maint.c as well, to untangle the maze
of ifdefs, and allow a sensible final ordering.

Move some declarations from exec/translate-all.h to internal.h,
as they are only used within accel/tcg/.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2022-10-05 18:06:29 -07:00
parent babcbc220b
commit 6ca5ac139f
4 changed files with 411 additions and 437 deletions

View File

@ -23,62 +23,28 @@
#define assert_memory_lock() tcg_debug_assert(have_mmap_lock())
#endif
typedef struct PageDesc PageDesc;
#ifndef CONFIG_USER_ONLY
struct PageDesc {
QemuSpin lock;
/* list of TBs intersecting this ram page */
uintptr_t first_tb;
};
PageDesc *page_find_alloc(tb_page_addr_t index, bool alloc);
static inline PageDesc *page_find(tb_page_addr_t index)
{
return page_find_alloc(index, false);
}
void page_table_config_init(void);
#else
static inline void page_table_config_init(void) { }
#endif
/* list iterators for lists of tagged pointers in TranslationBlock */
#define TB_FOR_EACH_TAGGED(head, tb, n, field) \
for (n = (head) & 1, tb = (TranslationBlock *)((head) & ~1); \
tb; tb = (TranslationBlock *)tb->field[n], n = (uintptr_t)tb & 1, \
tb = (TranslationBlock *)((uintptr_t)tb & ~1))
#define TB_FOR_EACH_JMP(head_tb, tb, n) \
TB_FOR_EACH_TAGGED((head_tb)->jmp_list_head, tb, n, jmp_list_next)
/* In user-mode page locks aren't used; mmap_lock is enough */
#ifdef CONFIG_USER_ONLY
#define assert_page_locked(pd) tcg_debug_assert(have_mmap_lock())
static inline void page_lock(PageDesc *pd) { }
static inline void page_unlock(PageDesc *pd) { }
#else
#ifdef CONFIG_DEBUG_TCG
void do_assert_page_locked(const PageDesc *pd, const char *file, int line);
#define assert_page_locked(pd) do_assert_page_locked(pd, __FILE__, __LINE__)
#else
#define assert_page_locked(pd)
#endif
void page_lock(PageDesc *pd);
void page_unlock(PageDesc *pd);
/* TODO: For now, still shared with translate-all.c for system mode. */
typedef int PageForEachNext;
#define PAGE_FOR_EACH_TB(start, end, pagedesc, tb, n) \
TB_FOR_EACH_TAGGED((pagedesc)->first_tb, tb, n, page_next)
#endif
#if !defined(CONFIG_USER_ONLY) && defined(CONFIG_DEBUG_TCG)
#if defined(CONFIG_SOFTMMU) && defined(CONFIG_DEBUG_TCG)
void assert_no_pages_locked(void);
#else
static inline void assert_no_pages_locked(void) { }
#endif
#ifdef CONFIG_USER_ONLY
static inline void page_table_config_init(void) { }
#else
void page_table_config_init(void);
#endif
#ifdef CONFIG_SOFTMMU
struct page_collection;
void tb_invalidate_phys_page_fast(struct page_collection *pages,
tb_page_addr_t start, int len,
uintptr_t retaddr);
struct page_collection *page_collection_lock(tb_page_addr_t start,
tb_page_addr_t end);
void page_collection_unlock(struct page_collection *set);
#endif /* CONFIG_SOFTMMU */
TranslationBlock *tb_gen_code(CPUState *cpu, target_ulong pc,
target_ulong cs_base, uint32_t flags,
int cflags);

View File

@ -30,6 +30,15 @@
#include "internal.h"
/* List iterators for lists of tagged pointers in TranslationBlock. */
#define TB_FOR_EACH_TAGGED(head, tb, n, field) \
for (n = (head) & 1, tb = (TranslationBlock *)((head) & ~1); \
tb; tb = (TranslationBlock *)tb->field[n], n = (uintptr_t)tb & 1, \
tb = (TranslationBlock *)((uintptr_t)tb & ~1))
#define TB_FOR_EACH_JMP(head_tb, tb, n) \
TB_FOR_EACH_TAGGED((head_tb)->jmp_list_head, tb, n, jmp_list_next)
static bool tb_cmp(const void *ap, const void *bp)
{
const TranslationBlock *a = ap;
@ -51,7 +60,27 @@ void tb_htable_init(void)
qht_init(&tb_ctx.htable, tb_cmp, CODE_GEN_HTABLE_SIZE, mode);
}
typedef struct PageDesc PageDesc;
#ifdef CONFIG_USER_ONLY
/*
* In user-mode page locks aren't used; mmap_lock is enough.
*/
#define assert_page_locked(pd) tcg_debug_assert(have_mmap_lock())
static inline void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1,
PageDesc **ret_p2, tb_page_addr_t phys2,
bool alloc)
{
*ret_p1 = NULL;
*ret_p2 = NULL;
}
static inline void page_unlock(PageDesc *pd) { }
static inline void page_lock_tb(const TranslationBlock *tb) { }
static inline void page_unlock_tb(const TranslationBlock *tb) { }
/*
* For user-only, since we are protecting all of memory with a single lock,
* and because the two pages of a TranslationBlock are always contiguous,
@ -157,6 +186,12 @@ static int v_l2_levels;
static void *l1_map[V_L1_MAX_SIZE];
struct PageDesc {
QemuSpin lock;
/* list of TBs intersecting this ram page */
uintptr_t first_tb;
};
void page_table_config_init(void)
{
uint32_t v_l1_bits;
@ -177,7 +212,7 @@ void page_table_config_init(void)
assert(v_l2_levels >= 0);
}
PageDesc *page_find_alloc(tb_page_addr_t index, bool alloc)
static PageDesc *page_find_alloc(tb_page_addr_t index, bool alloc)
{
PageDesc *pd;
void **lp;
@ -233,6 +268,303 @@ PageDesc *page_find_alloc(tb_page_addr_t index, bool alloc)
return pd + (index & (V_L2_SIZE - 1));
}
static inline PageDesc *page_find(tb_page_addr_t index)
{
return page_find_alloc(index, false);
}
/**
* struct page_entry - page descriptor entry
* @pd: pointer to the &struct PageDesc of the page this entry represents
* @index: page index of the page
* @locked: whether the page is locked
*
* This struct helps us keep track of the locked state of a page, without
* bloating &struct PageDesc.
*
* A page lock protects accesses to all fields of &struct PageDesc.
*
* See also: &struct page_collection.
*/
struct page_entry {
PageDesc *pd;
tb_page_addr_t index;
bool locked;
};
/**
* struct page_collection - tracks a set of pages (i.e. &struct page_entry's)
* @tree: Binary search tree (BST) of the pages, with key == page index
* @max: Pointer to the page in @tree with the highest page index
*
* To avoid deadlock we lock pages in ascending order of page index.
* When operating on a set of pages, we need to keep track of them so that
* we can lock them in order and also unlock them later. For this we collect
* pages (i.e. &struct page_entry's) in a binary search @tree. Given that the
* @tree implementation we use does not provide an O(1) operation to obtain the
* highest-ranked element, we use @max to keep track of the inserted page
* with the highest index. This is valuable because if a page is not in
* the tree and its index is higher than @max's, then we can lock it
* without breaking the locking order rule.
*
* Note on naming: 'struct page_set' would be shorter, but we already have a few
* page_set_*() helpers, so page_collection is used instead to avoid confusion.
*
* See also: page_collection_lock().
*/
struct page_collection {
GTree *tree;
struct page_entry *max;
};
typedef int PageForEachNext;
#define PAGE_FOR_EACH_TB(start, end, pagedesc, tb, n) \
TB_FOR_EACH_TAGGED((pagedesc)->first_tb, tb, n, page_next)
#ifdef CONFIG_DEBUG_TCG
static __thread GHashTable *ht_pages_locked_debug;
static void ht_pages_locked_debug_init(void)
{
if (ht_pages_locked_debug) {
return;
}
ht_pages_locked_debug = g_hash_table_new(NULL, NULL);
}
static bool page_is_locked(const PageDesc *pd)
{
PageDesc *found;
ht_pages_locked_debug_init();
found = g_hash_table_lookup(ht_pages_locked_debug, pd);
return !!found;
}
static void page_lock__debug(PageDesc *pd)
{
ht_pages_locked_debug_init();
g_assert(!page_is_locked(pd));
g_hash_table_insert(ht_pages_locked_debug, pd, pd);
}
static void page_unlock__debug(const PageDesc *pd)
{
bool removed;
ht_pages_locked_debug_init();
g_assert(page_is_locked(pd));
removed = g_hash_table_remove(ht_pages_locked_debug, pd);
g_assert(removed);
}
static void do_assert_page_locked(const PageDesc *pd,
const char *file, int line)
{
if (unlikely(!page_is_locked(pd))) {
error_report("assert_page_lock: PageDesc %p not locked @ %s:%d",
pd, file, line);
abort();
}
}
#define assert_page_locked(pd) do_assert_page_locked(pd, __FILE__, __LINE__)
void assert_no_pages_locked(void)
{
ht_pages_locked_debug_init();
g_assert(g_hash_table_size(ht_pages_locked_debug) == 0);
}
#else /* !CONFIG_DEBUG_TCG */
static inline void page_lock__debug(const PageDesc *pd) { }
static inline void page_unlock__debug(const PageDesc *pd) { }
static inline void assert_page_locked(const PageDesc *pd) { }
#endif /* CONFIG_DEBUG_TCG */
static void page_lock(PageDesc *pd)
{
page_lock__debug(pd);
qemu_spin_lock(&pd->lock);
}
static void page_unlock(PageDesc *pd)
{
qemu_spin_unlock(&pd->lock);
page_unlock__debug(pd);
}
static inline struct page_entry *
page_entry_new(PageDesc *pd, tb_page_addr_t index)
{
struct page_entry *pe = g_malloc(sizeof(*pe));
pe->index = index;
pe->pd = pd;
pe->locked = false;
return pe;
}
static void page_entry_destroy(gpointer p)
{
struct page_entry *pe = p;
g_assert(pe->locked);
page_unlock(pe->pd);
g_free(pe);
}
/* returns false on success */
static bool page_entry_trylock(struct page_entry *pe)
{
bool busy;
busy = qemu_spin_trylock(&pe->pd->lock);
if (!busy) {
g_assert(!pe->locked);
pe->locked = true;
page_lock__debug(pe->pd);
}
return busy;
}
static void do_page_entry_lock(struct page_entry *pe)
{
page_lock(pe->pd);
g_assert(!pe->locked);
pe->locked = true;
}
static gboolean page_entry_lock(gpointer key, gpointer value, gpointer data)
{
struct page_entry *pe = value;
do_page_entry_lock(pe);
return FALSE;
}
static gboolean page_entry_unlock(gpointer key, gpointer value, gpointer data)
{
struct page_entry *pe = value;
if (pe->locked) {
pe->locked = false;
page_unlock(pe->pd);
}
return FALSE;
}
/*
* Trylock a page, and if successful, add the page to a collection.
* Returns true ("busy") if the page could not be locked; false otherwise.
*/
static bool page_trylock_add(struct page_collection *set, tb_page_addr_t addr)
{
tb_page_addr_t index = addr >> TARGET_PAGE_BITS;
struct page_entry *pe;
PageDesc *pd;
pe = g_tree_lookup(set->tree, &index);
if (pe) {
return false;
}
pd = page_find(index);
if (pd == NULL) {
return false;
}
pe = page_entry_new(pd, index);
g_tree_insert(set->tree, &pe->index, pe);
/*
* If this is either (1) the first insertion or (2) a page whose index
* is higher than any other so far, just lock the page and move on.
*/
if (set->max == NULL || pe->index > set->max->index) {
set->max = pe;
do_page_entry_lock(pe);
return false;
}
/*
* Try to acquire out-of-order lock; if busy, return busy so that we acquire
* locks in order.
*/
return page_entry_trylock(pe);
}
static gint tb_page_addr_cmp(gconstpointer ap, gconstpointer bp, gpointer udata)
{
tb_page_addr_t a = *(const tb_page_addr_t *)ap;
tb_page_addr_t b = *(const tb_page_addr_t *)bp;
if (a == b) {
return 0;
} else if (a < b) {
return -1;
}
return 1;
}
/*
* Lock a range of pages ([@start,@end[) as well as the pages of all
* intersecting TBs.
* Locking order: acquire locks in ascending order of page index.
*/
struct page_collection *
page_collection_lock(tb_page_addr_t start, tb_page_addr_t end)
{
struct page_collection *set = g_malloc(sizeof(*set));
tb_page_addr_t index;
PageDesc *pd;
start >>= TARGET_PAGE_BITS;
end >>= TARGET_PAGE_BITS;
g_assert(start <= end);
set->tree = g_tree_new_full(tb_page_addr_cmp, NULL, NULL,
page_entry_destroy);
set->max = NULL;
assert_no_pages_locked();
retry:
g_tree_foreach(set->tree, page_entry_lock, NULL);
for (index = start; index <= end; index++) {
TranslationBlock *tb;
PageForEachNext n;
pd = page_find(index);
if (pd == NULL) {
continue;
}
if (page_trylock_add(set, index << TARGET_PAGE_BITS)) {
g_tree_foreach(set->tree, page_entry_unlock, NULL);
goto retry;
}
assert_page_locked(pd);
PAGE_FOR_EACH_TB(unused, unused, pd, tb, n) {
if (page_trylock_add(set, tb_page_addr0(tb)) ||
(tb_page_addr1(tb) != -1 &&
page_trylock_add(set, tb_page_addr1(tb)))) {
/* drop all locks, and reacquire in order */
g_tree_foreach(set->tree, page_entry_unlock, NULL);
goto retry;
}
}
}
return set;
}
void page_collection_unlock(struct page_collection *set)
{
/* entries are unlocked and freed via page_entry_destroy */
g_tree_destroy(set->tree);
g_free(set);
}
/* Set to NULL all the 'first_tb' fields in all PageDescs. */
static void tb_remove_all_1(int level, void **lp)
{
@ -329,6 +661,66 @@ static void tb_remove(TranslationBlock *tb)
tb_page_remove(pd, tb);
}
}
static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1,
PageDesc **ret_p2, tb_page_addr_t phys2, bool alloc)
{
PageDesc *p1, *p2;
tb_page_addr_t page1;
tb_page_addr_t page2;
assert_memory_lock();
g_assert(phys1 != -1);
page1 = phys1 >> TARGET_PAGE_BITS;
page2 = phys2 >> TARGET_PAGE_BITS;
p1 = page_find_alloc(page1, alloc);
if (ret_p1) {
*ret_p1 = p1;
}
if (likely(phys2 == -1)) {
page_lock(p1);
return;
} else if (page1 == page2) {
page_lock(p1);
if (ret_p2) {
*ret_p2 = p1;
}
return;
}
p2 = page_find_alloc(page2, alloc);
if (ret_p2) {
*ret_p2 = p2;
}
if (page1 < page2) {
page_lock(p1);
page_lock(p2);
} else {
page_lock(p2);
page_lock(p1);
}
}
/* lock the page(s) of a TB in the correct acquisition order */
static void page_lock_tb(const TranslationBlock *tb)
{
page_lock_pair(NULL, tb_page_addr0(tb), NULL, tb_page_addr1(tb), false);
}
static void page_unlock_tb(const TranslationBlock *tb)
{
PageDesc *p1 = page_find(tb_page_addr0(tb) >> TARGET_PAGE_BITS);
page_unlock(p1);
if (unlikely(tb_page_addr1(tb) != -1)) {
PageDesc *p2 = page_find(tb_page_addr1(tb) >> TARGET_PAGE_BITS);
if (p2 != p1) {
page_unlock(p2);
}
}
}
#endif /* CONFIG_USER_ONLY */
/* flush all the translation blocks */
@ -525,78 +917,6 @@ static void tb_phys_invalidate__locked(TranslationBlock *tb)
qemu_thread_jit_execute();
}
#ifdef CONFIG_USER_ONLY
static inline void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1,
PageDesc **ret_p2, tb_page_addr_t phys2,
bool alloc)
{
*ret_p1 = NULL;
*ret_p2 = NULL;
}
static inline void page_lock_tb(const TranslationBlock *tb) { }
static inline void page_unlock_tb(const TranslationBlock *tb) { }
#else
static void page_lock_pair(PageDesc **ret_p1, tb_page_addr_t phys1,
PageDesc **ret_p2, tb_page_addr_t phys2, bool alloc)
{
PageDesc *p1, *p2;
tb_page_addr_t page1;
tb_page_addr_t page2;
assert_memory_lock();
g_assert(phys1 != -1);
page1 = phys1 >> TARGET_PAGE_BITS;
page2 = phys2 >> TARGET_PAGE_BITS;
p1 = page_find_alloc(page1, alloc);
if (ret_p1) {
*ret_p1 = p1;
}
if (likely(phys2 == -1)) {
page_lock(p1);
return;
} else if (page1 == page2) {
page_lock(p1);
if (ret_p2) {
*ret_p2 = p1;
}
return;
}
p2 = page_find_alloc(page2, alloc);
if (ret_p2) {
*ret_p2 = p2;
}
if (page1 < page2) {
page_lock(p1);
page_lock(p2);
} else {
page_lock(p2);
page_lock(p1);
}
}
/* lock the page(s) of a TB in the correct acquisition order */
static void page_lock_tb(const TranslationBlock *tb)
{
page_lock_pair(NULL, tb_page_addr0(tb), NULL, tb_page_addr1(tb), false);
}
static void page_unlock_tb(const TranslationBlock *tb)
{
PageDesc *p1 = page_find(tb_page_addr0(tb) >> TARGET_PAGE_BITS);
page_unlock(p1);
if (unlikely(tb_page_addr1(tb) != -1)) {
PageDesc *p2 = page_find(tb_page_addr1(tb) >> TARGET_PAGE_BITS);
if (p2 != p1) {
page_unlock(p2);
}
}
}
#endif
/*
* Invalidate one TB.
* Called with mmap_lock held in user-mode.
@ -746,8 +1066,7 @@ bool tb_invalidate_phys_page_unwind(tb_page_addr_t addr, uintptr_t pc)
#else
/*
* @p must be non-NULL.
* user-mode: call with mmap_lock held.
* !user-mode: call with all @pages locked.
* Call with all @pages locked.
*/
static void
tb_invalidate_phys_page_range__locked(struct page_collection *pages,
@ -817,8 +1136,6 @@ tb_invalidate_phys_page_range__locked(struct page_collection *pages,
/*
* Invalidate all TBs which intersect with the target physical
* address page @addr.
*
* Called with mmap_lock held for user-mode emulation
*/
void tb_invalidate_phys_page(tb_page_addr_t addr)
{
@ -844,8 +1161,6 @@ void tb_invalidate_phys_page(tb_page_addr_t addr)
* 'is_cpu_write_access' should be true if called from a real cpu write
* access: the virtual CPU will exit the current TB if code is modified inside
* this TB.
*
* Called with mmap_lock held for user-mode emulation.
*/
void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
{

View File

@ -63,52 +63,6 @@
#include "tb-context.h"
#include "internal.h"
/* make various TB consistency checks */
/**
* struct page_entry - page descriptor entry
* @pd: pointer to the &struct PageDesc of the page this entry represents
* @index: page index of the page
* @locked: whether the page is locked
*
* This struct helps us keep track of the locked state of a page, without
* bloating &struct PageDesc.
*
* A page lock protects accesses to all fields of &struct PageDesc.
*
* See also: &struct page_collection.
*/
struct page_entry {
PageDesc *pd;
tb_page_addr_t index;
bool locked;
};
/**
* struct page_collection - tracks a set of pages (i.e. &struct page_entry's)
* @tree: Binary search tree (BST) of the pages, with key == page index
* @max: Pointer to the page in @tree with the highest page index
*
* To avoid deadlock we lock pages in ascending order of page index.
* When operating on a set of pages, we need to keep track of them so that
* we can lock them in order and also unlock them later. For this we collect
* pages (i.e. &struct page_entry's) in a binary search @tree. Given that the
* @tree implementation we use does not provide an O(1) operation to obtain the
* highest-ranked element, we use @max to keep track of the inserted page
* with the highest index. This is valuable because if a page is not in
* the tree and its index is higher than @max's, then we can lock it
* without breaking the locking order rule.
*
* Note on naming: 'struct page_set' would be shorter, but we already have a few
* page_set_*() helpers, so page_collection is used instead to avoid confusion.
*
* See also: page_collection_lock().
*/
struct page_collection {
GTree *tree;
struct page_entry *max;
};
/* Make sure all possible CPU event bits fit in tb->trace_vcpu_dstate */
QEMU_BUILD_BUG_ON(CPU_TRACE_DSTATE_MAX_EVENTS >
sizeof_field(TranslationBlock, trace_vcpu_dstate)
@ -310,261 +264,6 @@ void page_init(void)
page_table_config_init();
}
/* In user-mode page locks aren't used; mmap_lock is enough */
#ifdef CONFIG_USER_ONLY
struct page_collection *
page_collection_lock(tb_page_addr_t start, tb_page_addr_t end)
{
return NULL;
}
void page_collection_unlock(struct page_collection *set)
{ }
#else /* !CONFIG_USER_ONLY */
#ifdef CONFIG_DEBUG_TCG
static __thread GHashTable *ht_pages_locked_debug;
static void ht_pages_locked_debug_init(void)
{
if (ht_pages_locked_debug) {
return;
}
ht_pages_locked_debug = g_hash_table_new(NULL, NULL);
}
static bool page_is_locked(const PageDesc *pd)
{
PageDesc *found;
ht_pages_locked_debug_init();
found = g_hash_table_lookup(ht_pages_locked_debug, pd);
return !!found;
}
static void page_lock__debug(PageDesc *pd)
{
ht_pages_locked_debug_init();
g_assert(!page_is_locked(pd));
g_hash_table_insert(ht_pages_locked_debug, pd, pd);
}
static void page_unlock__debug(const PageDesc *pd)
{
bool removed;
ht_pages_locked_debug_init();
g_assert(page_is_locked(pd));
removed = g_hash_table_remove(ht_pages_locked_debug, pd);
g_assert(removed);
}
void do_assert_page_locked(const PageDesc *pd, const char *file, int line)
{
if (unlikely(!page_is_locked(pd))) {
error_report("assert_page_lock: PageDesc %p not locked @ %s:%d",
pd, file, line);
abort();
}
}
void assert_no_pages_locked(void)
{
ht_pages_locked_debug_init();
g_assert(g_hash_table_size(ht_pages_locked_debug) == 0);
}
#else /* !CONFIG_DEBUG_TCG */
static inline void page_lock__debug(const PageDesc *pd) { }
static inline void page_unlock__debug(const PageDesc *pd) { }
#endif /* CONFIG_DEBUG_TCG */
void page_lock(PageDesc *pd)
{
page_lock__debug(pd);
qemu_spin_lock(&pd->lock);
}
void page_unlock(PageDesc *pd)
{
qemu_spin_unlock(&pd->lock);
page_unlock__debug(pd);
}
static inline struct page_entry *
page_entry_new(PageDesc *pd, tb_page_addr_t index)
{
struct page_entry *pe = g_malloc(sizeof(*pe));
pe->index = index;
pe->pd = pd;
pe->locked = false;
return pe;
}
static void page_entry_destroy(gpointer p)
{
struct page_entry *pe = p;
g_assert(pe->locked);
page_unlock(pe->pd);
g_free(pe);
}
/* returns false on success */
static bool page_entry_trylock(struct page_entry *pe)
{
bool busy;
busy = qemu_spin_trylock(&pe->pd->lock);
if (!busy) {
g_assert(!pe->locked);
pe->locked = true;
page_lock__debug(pe->pd);
}
return busy;
}
static void do_page_entry_lock(struct page_entry *pe)
{
page_lock(pe->pd);
g_assert(!pe->locked);
pe->locked = true;
}
static gboolean page_entry_lock(gpointer key, gpointer value, gpointer data)
{
struct page_entry *pe = value;
do_page_entry_lock(pe);
return FALSE;
}
static gboolean page_entry_unlock(gpointer key, gpointer value, gpointer data)
{
struct page_entry *pe = value;
if (pe->locked) {
pe->locked = false;
page_unlock(pe->pd);
}
return FALSE;
}
/*
* Trylock a page, and if successful, add the page to a collection.
* Returns true ("busy") if the page could not be locked; false otherwise.
*/
static bool page_trylock_add(struct page_collection *set, tb_page_addr_t addr)
{
tb_page_addr_t index = addr >> TARGET_PAGE_BITS;
struct page_entry *pe;
PageDesc *pd;
pe = g_tree_lookup(set->tree, &index);
if (pe) {
return false;
}
pd = page_find(index);
if (pd == NULL) {
return false;
}
pe = page_entry_new(pd, index);
g_tree_insert(set->tree, &pe->index, pe);
/*
* If this is either (1) the first insertion or (2) a page whose index
* is higher than any other so far, just lock the page and move on.
*/
if (set->max == NULL || pe->index > set->max->index) {
set->max = pe;
do_page_entry_lock(pe);
return false;
}
/*
* Try to acquire out-of-order lock; if busy, return busy so that we acquire
* locks in order.
*/
return page_entry_trylock(pe);
}
static gint tb_page_addr_cmp(gconstpointer ap, gconstpointer bp, gpointer udata)
{
tb_page_addr_t a = *(const tb_page_addr_t *)ap;
tb_page_addr_t b = *(const tb_page_addr_t *)bp;
if (a == b) {
return 0;
} else if (a < b) {
return -1;
}
return 1;
}
/*
* Lock a range of pages ([@start,@end[) as well as the pages of all
* intersecting TBs.
* Locking order: acquire locks in ascending order of page index.
*/
struct page_collection *
page_collection_lock(tb_page_addr_t start, tb_page_addr_t end)
{
struct page_collection *set = g_malloc(sizeof(*set));
tb_page_addr_t index;
PageDesc *pd;
start >>= TARGET_PAGE_BITS;
end >>= TARGET_PAGE_BITS;
g_assert(start <= end);
set->tree = g_tree_new_full(tb_page_addr_cmp, NULL, NULL,
page_entry_destroy);
set->max = NULL;
assert_no_pages_locked();
retry:
g_tree_foreach(set->tree, page_entry_lock, NULL);
for (index = start; index <= end; index++) {
TranslationBlock *tb;
PageForEachNext n;
pd = page_find(index);
if (pd == NULL) {
continue;
}
if (page_trylock_add(set, index << TARGET_PAGE_BITS)) {
g_tree_foreach(set->tree, page_entry_unlock, NULL);
goto retry;
}
assert_page_locked(pd);
PAGE_FOR_EACH_TB(unused, unused, pd, tb, n) {
if (page_trylock_add(set, tb_page_addr0(tb)) ||
(tb_page_addr1(tb) != -1 &&
page_trylock_add(set, tb_page_addr1(tb)))) {
/* drop all locks, and reacquire in order */
g_tree_foreach(set->tree, page_entry_unlock, NULL);
goto retry;
}
}
}
return set;
}
void page_collection_unlock(struct page_collection *set)
{
/* entries are unlocked and freed via page_entry_destroy */
g_tree_destroy(set->tree);
g_free(set);
}
#endif /* !CONFIG_USER_ONLY */
/*
* Isolate the portion of code gen which can setjmp/longjmp.
* Return the size of the generated code, or negative on error.

View File

@ -23,12 +23,6 @@
/* translate-all.c */
struct page_collection *page_collection_lock(tb_page_addr_t start,
tb_page_addr_t end);
void page_collection_unlock(struct page_collection *set);
void tb_invalidate_phys_page_fast(struct page_collection *pages,
tb_page_addr_t start, int len,
uintptr_t retaddr);
void tb_invalidate_phys_page(tb_page_addr_t addr);
void tb_check_watchpoint(CPUState *cpu, uintptr_t retaddr);