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qemu-e2k/accel/tcg/tb-maint.c

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/*
* Translation Block Maintenance
*
* Copyright (c) 2003 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/interval-tree.h"
#include "qemu/qtree.h"
#include "exec/cputlb.h"
#include "exec/log.h"
#include "exec/exec-all.h"
#include "exec/tb-flush.h"
#include "exec/translate-all.h"
#include "sysemu/tcg.h"
#include "tcg/tcg.h"
#include "tb-hash.h"
#include "tb-context.h"
#include "internal-common.h"
#include "internal-target.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;
const TranslationBlock *b = bp;
return ((tb_cflags(a) & CF_PCREL || a->pc == b->pc) &&
a->cs_base == b->cs_base &&
a->flags == b->flags &&
(tb_cflags(a) & ~CF_INVALID) == (tb_cflags(b) & ~CF_INVALID) &&
tb_page_addr0(a) == tb_page_addr0(b) &&
tb_page_addr1(a) == tb_page_addr1(b));
}
void tb_htable_init(void)
{
unsigned int mode = QHT_MODE_AUTO_RESIZE;
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 tb_lock_pages(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,
* use a single data structure to record all TranslationBlocks.
*/
static IntervalTreeRoot tb_root;
static void tb_remove_all(void)
{
assert_memory_lock();
memset(&tb_root, 0, sizeof(tb_root));
}
/* Call with mmap_lock held. */
static void tb_record(TranslationBlock *tb)
{
vaddr addr;
int flags;
assert_memory_lock();
tb->itree.last = tb->itree.start + tb->size - 1;
/* translator_loop() must have made all TB pages non-writable */
addr = tb_page_addr0(tb);
flags = page_get_flags(addr);
assert(!(flags & PAGE_WRITE));
addr = tb_page_addr1(tb);
if (addr != -1) {
flags = page_get_flags(addr);
assert(!(flags & PAGE_WRITE));
}
interval_tree_insert(&tb->itree, &tb_root);
}
/* Call with mmap_lock held. */
static void tb_remove(TranslationBlock *tb)
{
assert_memory_lock();
interval_tree_remove(&tb->itree, &tb_root);
}
/* TODO: For now, still shared with translate-all.c for system mode. */
#define PAGE_FOR_EACH_TB(start, last, pagedesc, T, N) \
for (T = foreach_tb_first(start, last), \
N = foreach_tb_next(T, start, last); \
T != NULL; \
T = N, N = foreach_tb_next(N, start, last))
typedef TranslationBlock *PageForEachNext;
static PageForEachNext foreach_tb_first(tb_page_addr_t start,
tb_page_addr_t last)
{
IntervalTreeNode *n = interval_tree_iter_first(&tb_root, start, last);
return n ? container_of(n, TranslationBlock, itree) : NULL;
}
static PageForEachNext foreach_tb_next(PageForEachNext tb,
tb_page_addr_t start,
tb_page_addr_t last)
{
IntervalTreeNode *n;
if (tb) {
n = interval_tree_iter_next(&tb->itree, start, last);
if (n) {
return container_of(n, TranslationBlock, itree);
}
}
return NULL;
}
#else
/*
* In system mode we want L1_MAP to be based on ram offsets.
*/
#if HOST_LONG_BITS < TARGET_PHYS_ADDR_SPACE_BITS
# define L1_MAP_ADDR_SPACE_BITS HOST_LONG_BITS
#else
# define L1_MAP_ADDR_SPACE_BITS TARGET_PHYS_ADDR_SPACE_BITS
#endif
/* Size of the L2 (and L3, etc) page tables. */
#define V_L2_BITS 10
#define V_L2_SIZE (1 << V_L2_BITS)
/*
* L1 Mapping properties
*/
static int v_l1_size;
static int v_l1_shift;
static int v_l2_levels;
/*
* The bottom level has pointers to PageDesc, and is indexed by
* anything from 4 to (V_L2_BITS + 3) bits, depending on target page size.
*/
#define V_L1_MIN_BITS 4
#define V_L1_MAX_BITS (V_L2_BITS + 3)
#define V_L1_MAX_SIZE (1 << V_L1_MAX_BITS)
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;
assert(TARGET_PAGE_BITS);
/* The bits remaining after N lower levels of page tables. */
v_l1_bits = (L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS) % V_L2_BITS;
if (v_l1_bits < V_L1_MIN_BITS) {
v_l1_bits += V_L2_BITS;
}
v_l1_size = 1 << v_l1_bits;
v_l1_shift = L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS - v_l1_bits;
v_l2_levels = v_l1_shift / V_L2_BITS - 1;
assert(v_l1_bits <= V_L1_MAX_BITS);
assert(v_l1_shift % V_L2_BITS == 0);
assert(v_l2_levels >= 0);
}
static PageDesc *page_find_alloc(tb_page_addr_t index, bool alloc)
{
PageDesc *pd;
void **lp;
/* Level 1. Always allocated. */
lp = l1_map + ((index >> v_l1_shift) & (v_l1_size - 1));
/* Level 2..N-1. */
for (int i = v_l2_levels; i > 0; i--) {
void **p = qatomic_rcu_read(lp);
if (p == NULL) {
void *existing;
if (!alloc) {
return NULL;
}
p = g_new0(void *, V_L2_SIZE);
existing = qatomic_cmpxchg(lp, NULL, p);
if (unlikely(existing)) {
g_free(p);
p = existing;
}
}
lp = p + ((index >> (i * V_L2_BITS)) & (V_L2_SIZE - 1));
}
pd = qatomic_rcu_read(lp);
if (pd == NULL) {
void *existing;
if (!alloc) {
return NULL;
}
pd = g_new0(PageDesc, V_L2_SIZE);
for (int i = 0; i < V_L2_SIZE; i++) {
qemu_spin_init(&pd[i].lock);
}
existing = qatomic_cmpxchg(lp, NULL, pd);
if (unlikely(existing)) {
for (int i = 0; i < V_L2_SIZE; i++) {
qemu_spin_destroy(&pd[i].lock);
}
g_free(pd);
pd = existing;
}
}
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 {
QTree *tree;
struct page_entry *max;
};
typedef int PageForEachNext;
#define PAGE_FOR_EACH_TB(start, last, 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);
}
/* Like qemu_spin_trylock, returns false on success */
static bool page_trylock(PageDesc *pd)
{
bool busy = qemu_spin_trylock(&pd->lock);
if (!busy) {
page_lock__debug(pd);
}
return busy;
}
static void page_unlock(PageDesc *pd)
{
qemu_spin_unlock(&pd->lock);
page_unlock__debug(pd);
}
void tb_lock_page0(tb_page_addr_t paddr)
{
page_lock(page_find_alloc(paddr >> TARGET_PAGE_BITS, true));
}
void tb_lock_page1(tb_page_addr_t paddr0, tb_page_addr_t paddr1)
{
tb_page_addr_t pindex0 = paddr0 >> TARGET_PAGE_BITS;
tb_page_addr_t pindex1 = paddr1 >> TARGET_PAGE_BITS;
PageDesc *pd0, *pd1;
if (pindex0 == pindex1) {
/* Identical pages, and the first page is already locked. */
return;
}
pd1 = page_find_alloc(pindex1, true);
if (pindex0 < pindex1) {
/* Correct locking order, we may block. */
page_lock(pd1);
return;
}
/* Incorrect locking order, we cannot block lest we deadlock. */
if (!page_trylock(pd1)) {
return;
}
/*
* Drop the lock on page0 and get both page locks in the right order.
* Restart translation via longjmp.
*/
pd0 = page_find_alloc(pindex0, false);
page_unlock(pd0);
page_lock(pd1);
page_lock(pd0);
siglongjmp(tcg_ctx->jmp_trans, -3);
}
void tb_unlock_page1(tb_page_addr_t paddr0, tb_page_addr_t paddr1)
{
tb_page_addr_t pindex0 = paddr0 >> TARGET_PAGE_BITS;
tb_page_addr_t pindex1 = paddr1 >> TARGET_PAGE_BITS;
if (pindex0 != pindex1) {
page_unlock(page_find_alloc(pindex1, false));
}
}
static void tb_lock_pages(TranslationBlock *tb)
{
tb_page_addr_t paddr0 = tb_page_addr0(tb);
tb_page_addr_t paddr1 = tb_page_addr1(tb);
tb_page_addr_t pindex0 = paddr0 >> TARGET_PAGE_BITS;
tb_page_addr_t pindex1 = paddr1 >> TARGET_PAGE_BITS;
if (unlikely(paddr0 == -1)) {
return;
}
if (unlikely(paddr1 != -1) && pindex0 != pindex1) {
if (pindex0 < pindex1) {
page_lock(page_find_alloc(pindex0, true));
page_lock(page_find_alloc(pindex1, true));
return;
}
page_lock(page_find_alloc(pindex1, true));
}
page_lock(page_find_alloc(pindex0, true));
}
void tb_unlock_pages(TranslationBlock *tb)
{
tb_page_addr_t paddr0 = tb_page_addr0(tb);
tb_page_addr_t paddr1 = tb_page_addr1(tb);
tb_page_addr_t pindex0 = paddr0 >> TARGET_PAGE_BITS;
tb_page_addr_t pindex1 = paddr1 >> TARGET_PAGE_BITS;
if (unlikely(paddr0 == -1)) {
return;
}
if (unlikely(paddr1 != -1) && pindex0 != pindex1) {
page_unlock(page_find_alloc(pindex1, false));
}
page_unlock(page_find_alloc(pindex0, false));
}
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 = page_trylock(pe->pd);
if (!busy) {
g_assert(!pe->locked);
pe->locked = true;
}
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 = q_tree_lookup(set->tree, &index);
if (pe) {
return false;
}
pd = page_find(index);
if (pd == NULL) {
return false;
}
pe = page_entry_new(pd, index);
q_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,@last]) as well as the pages of all
* intersecting TBs.
* Locking order: acquire locks in ascending order of page index.
*/
static struct page_collection *page_collection_lock(tb_page_addr_t start,
tb_page_addr_t last)
{
struct page_collection *set = g_malloc(sizeof(*set));
tb_page_addr_t index;
PageDesc *pd;
start >>= TARGET_PAGE_BITS;
last >>= TARGET_PAGE_BITS;
g_assert(start <= last);
set->tree = q_tree_new_full(tb_page_addr_cmp, NULL, NULL,
page_entry_destroy);
set->max = NULL;
assert_no_pages_locked();
retry:
q_tree_foreach(set->tree, page_entry_lock, NULL);
for (index = start; index <= last; index++) {
TranslationBlock *tb;
PageForEachNext n;
pd = page_find(index);
if (pd == NULL) {
continue;
}
if (page_trylock_add(set, index << TARGET_PAGE_BITS)) {
q_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 */
q_tree_foreach(set->tree, page_entry_unlock, NULL);
goto retry;
}
}
}
return set;
}
static void page_collection_unlock(struct page_collection *set)
{
/* entries are unlocked and freed via page_entry_destroy */
q_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)
{
int i;
if (*lp == NULL) {
return;
}
if (level == 0) {
PageDesc *pd = *lp;
for (i = 0; i < V_L2_SIZE; ++i) {
page_lock(&pd[i]);
pd[i].first_tb = (uintptr_t)NULL;
page_unlock(&pd[i]);
}
} else {
void **pp = *lp;
for (i = 0; i < V_L2_SIZE; ++i) {
tb_remove_all_1(level - 1, pp + i);
}
}
}
static void tb_remove_all(void)
{
int i, l1_sz = v_l1_size;
for (i = 0; i < l1_sz; i++) {
tb_remove_all_1(v_l2_levels, l1_map + i);
}
}
/*
* Add the tb in the target page and protect it if necessary.
* Called with @p->lock held.
*/
static void tb_page_add(PageDesc *p, TranslationBlock *tb, unsigned int n)
{
bool page_already_protected;
assert_page_locked(p);
tb->page_next[n] = p->first_tb;
page_already_protected = p->first_tb != 0;
p->first_tb = (uintptr_t)tb | n;
/*
* If some code is already present, then the pages are already
* protected. So we handle the case where only the first TB is
* allocated in a physical page.
*/
if (!page_already_protected) {
tlb_protect_code(tb->page_addr[n] & TARGET_PAGE_MASK);
}
}
static void tb_record(TranslationBlock *tb)
{
tb_page_addr_t paddr0 = tb_page_addr0(tb);
tb_page_addr_t paddr1 = tb_page_addr1(tb);
tb_page_addr_t pindex0 = paddr0 >> TARGET_PAGE_BITS;
tb_page_addr_t pindex1 = paddr0 >> TARGET_PAGE_BITS;
assert(paddr0 != -1);
if (unlikely(paddr1 != -1) && pindex0 != pindex1) {
tb_page_add(page_find_alloc(pindex1, false), tb, 1);
}
tb_page_add(page_find_alloc(pindex0, false), tb, 0);
}
static void tb_page_remove(PageDesc *pd, TranslationBlock *tb)
{
TranslationBlock *tb1;
uintptr_t *pprev;
PageForEachNext n1;
assert_page_locked(pd);
pprev = &pd->first_tb;
PAGE_FOR_EACH_TB(unused, unused, pd, tb1, n1) {
if (tb1 == tb) {
*pprev = tb1->page_next[n1];
return;
}
pprev = &tb1->page_next[n1];
}
g_assert_not_reached();
}
static void tb_remove(TranslationBlock *tb)
{
tb_page_addr_t paddr0 = tb_page_addr0(tb);
tb_page_addr_t paddr1 = tb_page_addr1(tb);
tb_page_addr_t pindex0 = paddr0 >> TARGET_PAGE_BITS;
tb_page_addr_t pindex1 = paddr0 >> TARGET_PAGE_BITS;
assert(paddr0 != -1);
if (unlikely(paddr1 != -1) && pindex0 != pindex1) {
tb_page_remove(page_find_alloc(pindex1, false), tb);
}
tb_page_remove(page_find_alloc(pindex0, false), tb);
}
#endif /* CONFIG_USER_ONLY */
/* flush all the translation blocks */
static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count)
{
bool did_flush = false;
mmap_lock();
/* If it is already been done on request of another CPU, just retry. */
if (tb_ctx.tb_flush_count != tb_flush_count.host_int) {
goto done;
}
did_flush = true;
CPU_FOREACH(cpu) {
tcg_flush_jmp_cache(cpu);
}
qht_reset_size(&tb_ctx.htable, CODE_GEN_HTABLE_SIZE);
tb_remove_all();
tcg_region_reset_all();
/* XXX: flush processor icache at this point if cache flush is expensive */
qatomic_inc(&tb_ctx.tb_flush_count);
done:
mmap_unlock();
if (did_flush) {
qemu_plugin_flush_cb();
}
}
void tb_flush(CPUState *cpu)
{
if (tcg_enabled()) {
unsigned tb_flush_count = qatomic_read(&tb_ctx.tb_flush_count);
if (cpu_in_serial_context(cpu)) {
do_tb_flush(cpu, RUN_ON_CPU_HOST_INT(tb_flush_count));
} else {
async_safe_run_on_cpu(cpu, do_tb_flush,
RUN_ON_CPU_HOST_INT(tb_flush_count));
}
}
}
/* remove @orig from its @n_orig-th jump list */
static inline void tb_remove_from_jmp_list(TranslationBlock *orig, int n_orig)
{
uintptr_t ptr, ptr_locked;
TranslationBlock *dest;
TranslationBlock *tb;
uintptr_t *pprev;
int n;
/* mark the LSB of jmp_dest[] so that no further jumps can be inserted */
ptr = qatomic_or_fetch(&orig->jmp_dest[n_orig], 1);
dest = (TranslationBlock *)(ptr & ~1);
if (dest == NULL) {
return;
}
qemu_spin_lock(&dest->jmp_lock);
/*
* While acquiring the lock, the jump might have been removed if the
* destination TB was invalidated; check again.
*/
ptr_locked = qatomic_read(&orig->jmp_dest[n_orig]);
if (ptr_locked != ptr) {
qemu_spin_unlock(&dest->jmp_lock);
/*
* The only possibility is that the jump was unlinked via
* tb_jump_unlink(dest). Seeing here another destination would be a bug,
* because we set the LSB above.
*/
g_assert(ptr_locked == 1 && dest->cflags & CF_INVALID);
return;
}
/*
* We first acquired the lock, and since the destination pointer matches,
* we know for sure that @orig is in the jmp list.
*/
pprev = &dest->jmp_list_head;
TB_FOR_EACH_JMP(dest, tb, n) {
if (tb == orig && n == n_orig) {
*pprev = tb->jmp_list_next[n];
/* no need to set orig->jmp_dest[n]; setting the LSB was enough */
qemu_spin_unlock(&dest->jmp_lock);
return;
}
pprev = &tb->jmp_list_next[n];
}
g_assert_not_reached();
}
/*
* Reset the jump entry 'n' of a TB so that it is not chained to another TB.
*/
void tb_reset_jump(TranslationBlock *tb, int n)
{
uintptr_t addr = (uintptr_t)(tb->tc.ptr + tb->jmp_reset_offset[n]);
tb_set_jmp_target(tb, n, addr);
}
/* remove any jumps to the TB */
static inline void tb_jmp_unlink(TranslationBlock *dest)
{
TranslationBlock *tb;
int n;
qemu_spin_lock(&dest->jmp_lock);
TB_FOR_EACH_JMP(dest, tb, n) {
tb_reset_jump(tb, n);
qatomic_and(&tb->jmp_dest[n], (uintptr_t)NULL | 1);
/* No need to clear the list entry; setting the dest ptr is enough */
}
dest->jmp_list_head = (uintptr_t)NULL;
qemu_spin_unlock(&dest->jmp_lock);
}
static void tb_jmp_cache_inval_tb(TranslationBlock *tb)
{
CPUState *cpu;
if (tb_cflags(tb) & CF_PCREL) {
/* A TB may be at any virtual address */
CPU_FOREACH(cpu) {
tcg_flush_jmp_cache(cpu);
}
} else {
uint32_t h = tb_jmp_cache_hash_func(tb->pc);
CPU_FOREACH(cpu) {
CPUJumpCache *jc = cpu->tb_jmp_cache;
if (qatomic_read(&jc->array[h].tb) == tb) {
qatomic_set(&jc->array[h].tb, NULL);
}
}
}
}
/*
* In user-mode, call with mmap_lock held.
* In !user-mode, if @rm_from_page_list is set, call with the TB's pages'
* locks held.
*/
static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list)
{
uint32_t h;
tb_page_addr_t phys_pc;
uint32_t orig_cflags = tb_cflags(tb);
assert_memory_lock();
/* make sure no further incoming jumps will be chained to this TB */
qemu_spin_lock(&tb->jmp_lock);
qatomic_set(&tb->cflags, tb->cflags | CF_INVALID);
qemu_spin_unlock(&tb->jmp_lock);
/* remove the TB from the hash list */
phys_pc = tb_page_addr0(tb);
h = tb_hash_func(phys_pc, (orig_cflags & CF_PCREL ? 0 : tb->pc),
tb->flags, tb->cs_base, orig_cflags);
if (!qht_remove(&tb_ctx.htable, tb, h)) {
return;
}
/* remove the TB from the page list */
if (rm_from_page_list) {
tb_remove(tb);
}
/* remove the TB from the hash list */
tb_jmp_cache_inval_tb(tb);
/* suppress this TB from the two jump lists */
tb_remove_from_jmp_list(tb, 0);
tb_remove_from_jmp_list(tb, 1);
/* suppress any remaining jumps to this TB */
tb_jmp_unlink(tb);
qatomic_set(&tb_ctx.tb_phys_invalidate_count,
tb_ctx.tb_phys_invalidate_count + 1);
}
static void tb_phys_invalidate__locked(TranslationBlock *tb)
{
qemu_thread_jit_write();
do_tb_phys_invalidate(tb, true);
qemu_thread_jit_execute();
}
/*
* Invalidate one TB.
* Called with mmap_lock held in user-mode.
*/
void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr)
{
if (page_addr == -1 && tb_page_addr0(tb) != -1) {
tb_lock_pages(tb);
do_tb_phys_invalidate(tb, true);
tb_unlock_pages(tb);
} else {
do_tb_phys_invalidate(tb, false);
}
}
/*
* Add a new TB and link it to the physical page tables.
* Called with mmap_lock held for user-mode emulation.
*
* Returns a pointer @tb, or a pointer to an existing TB that matches @tb.
* Note that in !user-mode, another thread might have already added a TB
* for the same block of guest code that @tb corresponds to. In that case,
* the caller should discard the original @tb, and use instead the returned TB.
*/
TranslationBlock *tb_link_page(TranslationBlock *tb)
{
void *existing_tb = NULL;
uint32_t h;
assert_memory_lock();
tcg_debug_assert(!(tb->cflags & CF_INVALID));
tb_record(tb);
/* add in the hash table */
h = tb_hash_func(tb_page_addr0(tb), (tb->cflags & CF_PCREL ? 0 : tb->pc),
tb->flags, tb->cs_base, tb->cflags);
qht_insert(&tb_ctx.htable, tb, h, &existing_tb);
/* remove TB from the page(s) if we couldn't insert it */
if (unlikely(existing_tb)) {
tb_remove(tb);
tb_unlock_pages(tb);
return existing_tb;
}
tb_unlock_pages(tb);
return tb;
}
#ifdef CONFIG_USER_ONLY
/*
* Invalidate all TBs which intersect with the target address range.
* Called with mmap_lock held for user-mode emulation.
* NOTE: this function must not be called while a TB is running.
*/
void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t last)
{
TranslationBlock *tb;
PageForEachNext n;
assert_memory_lock();
PAGE_FOR_EACH_TB(start, last, unused, tb, n) {
tb_phys_invalidate__locked(tb);
}
}
/*
* Invalidate all TBs which intersect with the target address page @addr.
* Called with mmap_lock held for user-mode emulation
* NOTE: this function must not be called while a TB is running.
*/
static void tb_invalidate_phys_page(tb_page_addr_t addr)
{
tb_page_addr_t start, last;
start = addr & TARGET_PAGE_MASK;
last = addr | ~TARGET_PAGE_MASK;
tb_invalidate_phys_range(start, last);
}
/*
* Called with mmap_lock held. If pc is not 0 then it indicates the
* host PC of the faulting store instruction that caused this invalidate.
* Returns true if the caller needs to abort execution of the current
* TB (because it was modified by this store and the guest CPU has
* precise-SMC semantics).
*/
bool tb_invalidate_phys_page_unwind(tb_page_addr_t addr, uintptr_t pc)
{
TranslationBlock *current_tb;
bool current_tb_modified;
TranslationBlock *tb;
PageForEachNext n;
tb_page_addr_t last;
/*
* Without precise smc semantics, or when outside of a TB,
* we can skip to invalidate.
*/
#ifndef TARGET_HAS_PRECISE_SMC
pc = 0;
#endif
if (!pc) {
tb_invalidate_phys_page(addr);
return false;
}
assert_memory_lock();
current_tb = tcg_tb_lookup(pc);
last = addr | ~TARGET_PAGE_MASK;
addr &= TARGET_PAGE_MASK;
current_tb_modified = false;
PAGE_FOR_EACH_TB(addr, last, unused, tb, n) {
if (current_tb == tb &&
(tb_cflags(current_tb) & CF_COUNT_MASK) != 1) {
/*
* If we are modifying the current TB, we must stop its
* execution. We could be more precise by checking that
* the modification is after the current PC, but it would
* require a specialized function to partially restore
* the CPU state.
*/
current_tb_modified = true;
cpu_restore_state_from_tb(current_cpu, current_tb, pc);
}
tb_phys_invalidate__locked(tb);
}
if (current_tb_modified) {
/* Force execution of one insn next time. */
CPUState *cpu = current_cpu;
cpu->cflags_next_tb = 1 | CF_NOIRQ | curr_cflags(current_cpu);
return true;
}
return false;
}
#else
/*
* @p must be non-NULL.
* Call with all @pages locked.
*/
static void
tb_invalidate_phys_page_range__locked(struct page_collection *pages,
PageDesc *p, tb_page_addr_t start,
tb_page_addr_t last,
uintptr_t retaddr)
{
TranslationBlock *tb;
PageForEachNext n;
#ifdef TARGET_HAS_PRECISE_SMC
bool current_tb_modified = false;
TranslationBlock *current_tb = retaddr ? tcg_tb_lookup(retaddr) : NULL;
#endif /* TARGET_HAS_PRECISE_SMC */
/* Range may not cross a page. */
tcg_debug_assert(((start ^ last) & TARGET_PAGE_MASK) == 0);
/*
* We remove all the TBs in the range [start, last].
* XXX: see if in some cases it could be faster to invalidate all the code
*/
PAGE_FOR_EACH_TB(start, last, p, tb, n) {
tb_page_addr_t tb_start, tb_last;
/* NOTE: this is subtle as a TB may span two physical pages */
tb_start = tb_page_addr0(tb);
tb_last = tb_start + tb->size - 1;
if (n == 0) {
tb_last = MIN(tb_last, tb_start | ~TARGET_PAGE_MASK);
} else {
tb_start = tb_page_addr1(tb);
tb_last = tb_start + (tb_last & ~TARGET_PAGE_MASK);
}
if (!(tb_last < start || tb_start > last)) {
#ifdef TARGET_HAS_PRECISE_SMC
if (current_tb == tb &&
(tb_cflags(current_tb) & CF_COUNT_MASK) != 1) {
/*
* If we are modifying the current TB, we must stop
* its execution. We could be more precise by checking
* that the modification is after the current PC, but it
* would require a specialized function to partially
* restore the CPU state.
*/
current_tb_modified = true;
cpu_restore_state_from_tb(current_cpu, current_tb, retaddr);
}
#endif /* TARGET_HAS_PRECISE_SMC */
tb_phys_invalidate__locked(tb);
}
}
/* if no code remaining, no need to continue to use slow writes */
if (!p->first_tb) {
tlb_unprotect_code(start);
}
#ifdef TARGET_HAS_PRECISE_SMC
if (current_tb_modified) {
page_collection_unlock(pages);
/* Force execution of one insn next time. */
current_cpu->cflags_next_tb = 1 | CF_NOIRQ | curr_cflags(current_cpu);
mmap_unlock();
cpu_loop_exit_noexc(current_cpu);
}
#endif
}
/*
* Invalidate all TBs which intersect with the target physical address range
* [start;last]. NOTE: start and end may refer to *different* physical pages.
* '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.
*/
void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t last)
{
struct page_collection *pages;
tb_page_addr_t index, index_last;
pages = page_collection_lock(start, last);
index_last = last >> TARGET_PAGE_BITS;
for (index = start >> TARGET_PAGE_BITS; index <= index_last; index++) {
PageDesc *pd = page_find(index);
tb_page_addr_t page_start, page_last;
if (pd == NULL) {
continue;
}
assert_page_locked(pd);
page_start = index << TARGET_PAGE_BITS;
page_last = page_start | ~TARGET_PAGE_MASK;
page_last = MIN(page_last, last);
tb_invalidate_phys_page_range__locked(pages, pd,
page_start, page_last, 0);
}
page_collection_unlock(pages);
}
/*
* Call with all @pages in the range [@start, @start + len[ locked.
*/
static void tb_invalidate_phys_page_fast__locked(struct page_collection *pages,
tb_page_addr_t start,
unsigned len, uintptr_t ra)
{
PageDesc *p;
p = page_find(start >> TARGET_PAGE_BITS);
if (!p) {
return;
}
assert_page_locked(p);
tb_invalidate_phys_page_range__locked(pages, p, start, start + len - 1, ra);
}
/*
* len must be <= 8 and start must be a multiple of len.
* Called via softmmu_template.h when code areas are written to with
* iothread mutex not held.
*/
void tb_invalidate_phys_range_fast(ram_addr_t ram_addr,
unsigned size,
uintptr_t retaddr)
{
struct page_collection *pages;
pages = page_collection_lock(ram_addr, ram_addr + size - 1);
tb_invalidate_phys_page_fast__locked(pages, ram_addr, size, retaddr);
page_collection_unlock(pages);
}
#endif /* CONFIG_USER_ONLY */
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