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

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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
2022-12-20 17:11:12 -08:00
parent babcbc220b
commit 6ca5ac139f
4 changed files with 411 additions and 437 deletions
Download Patch File Download Diff File Expand all files Collapse all files
accel/tcg/internal.h
+17 -51
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);
accel/tcg/tb-maint.c
+394 -79
View File
File diff suppressed because it is too large Load Diff
accel/tcg/translate-all.c
-301
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.
include/exec/translate-all.h
-6
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);