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[Qemu-devel] [RFC v4 19/28] tcg: move locking for tb_invalidate_phys_pag
From: |
Alex Bennée |
Subject: |
[Qemu-devel] [RFC v4 19/28] tcg: move locking for tb_invalidate_phys_page_range up |
Date: |
Thu, 11 Aug 2016 16:24:15 +0100 |
In the linux-user case all things that involve ''l1_map' and PageDesc
tweaks are protected by the memory lock (mmpa_lock). For SoftMMU mode
we previously relied on single threaded behaviour, with MTTCG we now use
the tb_lock().
As a result we need to do a little re-factoring and push the taking of
this lock up the call tree. This requires a slightly different entry for
the SoftMMU and user-mode cases from tb_invalidate_phys_range.
This also means user-mode breakpoint insertion needs to take two locks
but it hadn't taken any previously so this is an improvement.
Signed-off-by: Alex Bennée <address@hidden>
---
v4
- reword commit message
---
exec.c | 16 ++++++++++++++++
translate-all.c | 37 +++++++++++++++++++++++++++++--------
2 files changed, 45 insertions(+), 8 deletions(-)
diff --git a/exec.c b/exec.c
index a39a200..f418725 100644
--- a/exec.c
+++ b/exec.c
@@ -722,7 +722,11 @@ void cpu_exec_init(CPUState *cpu, Error **errp)
#if defined(CONFIG_USER_ONLY)
static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
{
+ mmap_lock();
+ tb_lock();
tb_invalidate_phys_page_range(pc, pc + 1, 0);
+ tb_unlock();
+ mmap_unlock();
}
#else
static void breakpoint_invalidate(CPUState *cpu, target_ulong pc)
@@ -731,6 +735,7 @@ static void breakpoint_invalidate(CPUState *cpu,
target_ulong pc)
hwaddr phys = cpu_get_phys_page_attrs_debug(cpu, pc, &attrs);
int asidx = cpu_asidx_from_attrs(cpu, attrs);
if (phys != -1) {
+ /* Locks grabbed by tb_invalidate_phys_addr */
tb_invalidate_phys_addr(cpu->cpu_ases[asidx].as,
phys | (pc & ~TARGET_PAGE_MASK));
}
@@ -2009,7 +2014,11 @@ ram_addr_t qemu_ram_addr_from_host(void *ptr)
static void notdirty_mem_write(void *opaque, hwaddr ram_addr,
uint64_t val, unsigned size)
{
+ bool locked = false;
+
if (!cpu_physical_memory_get_dirty_flag(ram_addr, DIRTY_MEMORY_CODE)) {
+ locked = true;
+ tb_lock();
tb_invalidate_phys_page_fast(ram_addr, size);
}
switch (size) {
@@ -2025,6 +2034,11 @@ static void notdirty_mem_write(void *opaque, hwaddr
ram_addr,
default:
abort();
}
+
+ if (locked) {
+ tb_unlock();
+ }
+
/* Set both VGA and migration bits for simplicity and to remove
* the notdirty callback faster.
*/
@@ -2505,7 +2519,9 @@ static void invalidate_and_set_dirty(MemoryRegion *mr,
hwaddr addr,
cpu_physical_memory_range_includes_clean(addr, length,
dirty_log_mask);
}
if (dirty_log_mask & (1 << DIRTY_MEMORY_CODE)) {
+ tb_lock();
tb_invalidate_phys_range(addr, addr + length);
+ tb_unlock();
dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
}
cpu_physical_memory_set_dirty_range(addr, length, dirty_log_mask);
diff --git a/translate-all.c b/translate-all.c
index c650696..c53ae8c 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -1363,12 +1363,11 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
* 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
+ * Called with mmap_lock held for user-mode emulation, grabs tb_lock
+ * Called with tb_lock held for system-mode emulation
*/
-void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
+static void tb_invalidate_phys_range_1(tb_page_addr_t start, tb_page_addr_t
end)
{
- assert_memory_lock();
-
while (start < end) {
tb_invalidate_phys_page_range(start, end, 0);
start &= TARGET_PAGE_MASK;
@@ -1376,6 +1375,21 @@ void tb_invalidate_phys_range(tb_page_addr_t start,
tb_page_addr_t end)
}
}
+#ifdef CONFIG_SOFTMMU
+void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
+{
+ assert_tb_lock();
+ tb_invalidate_phys_range_1(start, end);
+}
+#else
+void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end)
+{
+ assert_memory_lock();
+ tb_lock();
+ tb_invalidate_phys_range_1(start, end);
+ tb_unlock();
+}
+#endif
/*
* Invalidate all TBs which intersect with the target physical address range
* [start;end[. NOTE: start and end must refer to the *same* physical page.
@@ -1383,7 +1397,8 @@ void tb_invalidate_phys_range(tb_page_addr_t start,
tb_page_addr_t end)
* 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
+ * Called with tb_lock/mmap_lock held for user-mode emulation
+ * Called with tb_lock held for system-mode emulation
*/
void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end,
int is_cpu_write_access)
@@ -1406,6 +1421,7 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start,
tb_page_addr_t end,
#endif /* TARGET_HAS_PRECISE_SMC */
assert_memory_lock();
+ assert_tb_lock();
p = page_find(start >> TARGET_PAGE_BITS);
if (!p) {
@@ -1420,7 +1436,6 @@ void tb_invalidate_phys_page_range(tb_page_addr_t start,
tb_page_addr_t end,
/* we remove all the TBs in the range [start, end[ */
/* XXX: see if in some cases it could be faster to invalidate all
the code */
- tb_lock();
tb = p->first_tb;
while (tb != NULL) {
n = (uintptr_t)tb & 3;
@@ -1480,12 +1495,12 @@ void tb_invalidate_phys_page_range(tb_page_addr_t
start, tb_page_addr_t end,
cpu_loop_exit_noexc(cpu);
}
#endif
- tb_unlock();
}
#ifdef CONFIG_SOFTMMU
/* len must be <= 8 and start must be a multiple of len.
- * Called via softmmu_template.h, with iothread mutex not held.
+ * Called via softmmu_template.h when code areas are written to with
+ * tb_lock held.
*/
void tb_invalidate_phys_page_fast(tb_page_addr_t start, int len)
{
@@ -1500,6 +1515,8 @@ void tb_invalidate_phys_page_fast(tb_page_addr_t start,
int len)
(intptr_t)cpu_single_env->segs[R_CS].base);
}
#endif
+ assert_memory_lock();
+
p = page_find(start >> TARGET_PAGE_BITS);
if (!p) {
return;
@@ -1547,6 +1564,8 @@ static bool tb_invalidate_phys_page(tb_page_addr_t addr,
uintptr_t pc)
uint32_t current_flags = 0;
#endif
+ assert_memory_lock();
+
addr &= TARGET_PAGE_MASK;
p = page_find(addr >> TARGET_PAGE_BITS);
if (!p) {
@@ -1650,7 +1669,9 @@ void tb_invalidate_phys_addr(AddressSpace *as, hwaddr
addr)
return;
}
ram_addr = memory_region_get_ram_addr(mr) + addr;
+ tb_lock();
tb_invalidate_phys_page_range(ram_addr, ram_addr + 1, 0);
+ tb_unlock();
rcu_read_unlock();
}
#endif /* !defined(CONFIG_USER_ONLY) */
--
2.7.4
- [Qemu-devel] [RFC v4 07/28] linux-user/elfload: ensure mmap_lock() held while setting up, (continued)
- [Qemu-devel] [RFC v4 07/28] linux-user/elfload: ensure mmap_lock() held while setting up, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 06/28] tcg: comment on which functions have to be called with tb_lock held, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 15/28] tcg: rename tcg_current_cpu to tcg_current_rr_cpu, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 09/28] tcg: protect TBContext with tb_lock., Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 11/28] tcg: move tcg_exec_all and helpers above thread fn, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 14/28] tcg: add kick timer for single-threaded vCPU emulation, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 12/28] tcg: cpus rm tcg_exec_all(), Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 13/28] tcg: add options for enabling MTTCG, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 17/28] cpus: re-factor out handle_icount_deadline, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 18/28] tcg: remove global exit_request, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 19/28] tcg: move locking for tb_invalidate_phys_page_range up,
Alex Bennée <=
- [Qemu-devel] [RFC v4 16/28] tcg: drop global lock during TCG code execution, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 21/28] tcg: enable tb_lock() for SoftMMU, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 22/28] tcg: enable thread-per-vCPU, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 25/28] cputlb: introduce tlb_flush_* async work., Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 23/28] atomic: introduce cmpxchg_bool, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 24/28] cputlb: add assert_cpu_is_self checks, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 26/28] cputlb: tweak qemu_ram_addr_from_host_nofail reporting, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 20/28] cpus: tweak sleeping and safe_work rules for MTTCG, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 28/28] cputlb: make tlb_flush_by_mmuidx safe for MTTCG, Alex Bennée, 2016/08/11
- [Qemu-devel] [RFC v4 27/28] cputlb: make tlb_reset_dirty safe for MTTCG, Alex Bennée, 2016/08/11