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[Qemu-devel] [PATCH v5 09/33] tcg: protect translation related stuff wit
From: |
Alex Bennée |
Subject: |
[Qemu-devel] [PATCH v5 09/33] tcg: protect translation related stuff with tb_lock. |
Date: |
Thu, 27 Oct 2016 16:10:06 +0100 |
From: KONRAD Frederic <address@hidden>
This protects all translation related work with tb_lock() too ensure
thread safety. This effectively serialises all code generation. In
addition to the code generation we also take the lock for TB
invalidation. This has a knock on effect of meaning tb_lock() is held
for modification of the SoftMMU TLB by non-self threads which will be
used in later patches.
Signed-off-by: KONRAD Frederic <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Emilio G. Cota <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
[AJB: moved into tree, clean-up history]
Signed-off-by: Alex Bennée <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
---
v5 (base-patches, ajb):
- widen lock on cpu_restore_state to tb_find_pc doesn't race
- expanded commit message
v4 (base-patches, ajb):
- protect tb_phys_invalidate with tb_lock
- drop mention of tb_flush, thread safe flushing in earlier patch series
v3 (base-patches, ajb):
- more explicit comments on resetting tb_lock
- more explicit comments about thread safety of user-mode tb_flush
v2 (base-patches, ajb):
- re-base fixes
v7 (FK, MTTCG):
- Drop a tb_lock in already locked restore_state_to_opc.
v6 (FK, MTTCG):
- Drop a tb_lock arround tb_find_fast in cpu-exec.c.
---
cpu-exec.c | 6 ++++++
exec.c | 6 ++++++
hw/i386/kvmvapic.c | 4 ++++
translate-all.c | 34 ++++++++++++++++++++++++++++------
4 files changed, 44 insertions(+), 6 deletions(-)
diff --git a/cpu-exec.c b/cpu-exec.c
index 4879c7d..e9b50a6 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -211,15 +211,21 @@ static void cpu_exec_nocache(CPUState *cpu, int
max_cycles,
if (max_cycles > CF_COUNT_MASK)
max_cycles = CF_COUNT_MASK;
+ tb_lock();
tb = tb_gen_code(cpu, orig_tb->pc, orig_tb->cs_base, orig_tb->flags,
max_cycles | CF_NOCACHE
| (ignore_icount ? CF_IGNORE_ICOUNT : 0));
tb->orig_tb = orig_tb;
+ tb_unlock();
+
/* execute the generated code */
trace_exec_tb_nocache(tb, tb->pc);
cpu_tb_exec(cpu, tb);
+
+ tb_lock();
tb_phys_invalidate(tb, -1);
tb_free(tb);
+ tb_unlock();
}
#endif
diff --git a/exec.c b/exec.c
index 0096a54..30ae278 100644
--- a/exec.c
+++ b/exec.c
@@ -2023,6 +2023,12 @@ static void check_watchpoint(int offset, int len,
MemTxAttrs attrs, int flags)
continue;
}
cpu->watchpoint_hit = wp;
+
+ /* The tb_lock will be reset when cpu_loop_exit or
+ * cpu_loop_exit_noexc longjmp back into the cpu_exec
+ * main loop.
+ */
+ tb_lock();
tb_check_watchpoint(cpu);
if (wp->flags & BP_STOP_BEFORE_ACCESS) {
cpu->exception_index = EXCP_DEBUG;
diff --git a/hw/i386/kvmvapic.c b/hw/i386/kvmvapic.c
index 74a549b..4448253 100644
--- a/hw/i386/kvmvapic.c
+++ b/hw/i386/kvmvapic.c
@@ -17,6 +17,7 @@
#include "sysemu/kvm.h"
#include "hw/i386/apic_internal.h"
#include "hw/sysbus.h"
+#include "tcg/tcg.h"
#define VAPIC_IO_PORT 0x7e
@@ -449,6 +450,9 @@ static void patch_instruction(VAPICROMState *s, X86CPU
*cpu, target_ulong ip)
resume_all_vcpus();
if (!kvm_enabled()) {
+ /* tb_lock will be reset when cpu_loop_exit_noexc longjmps
+ * back into the cpu_exec loop. */
+ tb_lock();
tb_gen_code(cs, current_pc, current_cs_base, current_flags, 1);
cpu_loop_exit_noexc(cs);
}
diff --git a/translate-all.c b/translate-all.c
index 5460cf2..1237f3c 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -344,7 +344,9 @@ static int cpu_restore_state_from_tb(CPUState *cpu,
TranslationBlock *tb,
bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)
{
TranslationBlock *tb;
+ bool r = false;
+ tb_lock();
tb = tb_find_pc(retaddr);
if (tb) {
cpu_restore_state_from_tb(cpu, tb, retaddr);
@@ -353,9 +355,11 @@ bool cpu_restore_state(CPUState *cpu, uintptr_t retaddr)
tb_phys_invalidate(tb, -1);
tb_free(tb);
}
- return true;
+ r = true;
}
- return false;
+ tb_unlock();
+
+ return r;
}
void page_size_init(void)
@@ -1435,6 +1439,7 @@ 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;
@@ -1494,6 +1499,7 @@ 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
@@ -1563,6 +1569,8 @@ static bool tb_invalidate_phys_page(tb_page_addr_t addr,
uintptr_t pc)
if (!p) {
return false;
}
+
+ tb_lock();
tb = p->first_tb;
#ifdef TARGET_HAS_PRECISE_SMC
if (tb && pc != 0) {
@@ -1600,9 +1608,13 @@ static bool tb_invalidate_phys_page(tb_page_addr_t addr,
uintptr_t pc)
modifying the memory. It will ensure that it cannot modify
itself */
tb_gen_code(cpu, current_pc, current_cs_base, current_flags, 1);
+ /* tb_lock will be reset after cpu_loop_exit_noexc longjmps
+ * back into the cpu_exec loop. */
return true;
}
#endif
+ tb_unlock();
+
return false;
}
#endif
@@ -1697,6 +1709,7 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
target_ulong pc, cs_base;
uint32_t flags;
+ tb_lock();
tb = tb_find_pc(retaddr);
if (!tb) {
cpu_abort(cpu, "cpu_io_recompile: could not find TB for pc=%p",
@@ -1748,11 +1761,16 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
/* FIXME: In theory this could raise an exception. In practice
we have already translated the block once so it's probably ok. */
tb_gen_code(cpu, pc, cs_base, flags, cflags);
+
/* TODO: If env->pc != tb->pc (i.e. the faulting instruction was not
- the first in the TB) then we end up generating a whole new TB and
- repeating the fault, which is horribly inefficient.
- Better would be to execute just this insn uncached, or generate a
- second new TB. */
+ * the first in the TB) then we end up generating a whole new TB and
+ * repeating the fault, which is horribly inefficient.
+ * Better would be to execute just this insn uncached, or generate a
+ * second new TB.
+ *
+ * cpu_loop_exit_noexc will longjmp back to cpu_exec where the
+ * tb_lock gets reset.
+ */
cpu_loop_exit_noexc(cpu);
}
@@ -1816,6 +1834,8 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
TranslationBlock *tb;
struct qht_stats hst;
+ tb_lock();
+
target_code_size = 0;
max_target_code_size = 0;
cross_page = 0;
@@ -1877,6 +1897,8 @@ void dump_exec_info(FILE *f, fprintf_function cpu_fprintf)
tcg_ctx.tb_ctx.tb_phys_invalidate_count);
cpu_fprintf(f, "TLB flush count %d\n", tlb_flush_count);
tcg_dump_info(f, cpu_fprintf);
+
+ tb_unlock();
}
void dump_opcount_info(FILE *f, fprintf_function cpu_fprintf)
--
2.10.1
- [Qemu-devel] [PATCH v5 00/33] MTTCG Base Enabling patches with ARM on x86 defaults, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 02/33] translate_all: DEBUG_FLUSH -> DEBUG_TB_FLUSH, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 01/33] cpus: make all_vcpus_paused() return bool, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 04/33] cpu-exec: include cpu_index in CPU_LOG_EXEC messages, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 05/33] docs: new design document multi-thread-tcg.txt (DRAFTING), Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 07/33] linux-user/elfload: ensure mmap_lock() held while setting up, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 08/33] translate-all: Add assert_(memory|tb)_lock annotations, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 10/33] target-arm/arm-powerctl: wake up sleeping CPUs, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 03/33] translate-all: add DEBUG_LOCKING asserts, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 09/33] tcg: protect translation related stuff with tb_lock.,
Alex Bennée <=
- [Qemu-devel] [PATCH v5 12/33] tcg: cpus rm tcg_exec_all(), Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 14/33] tcg: add kick timer for single-threaded vCPU emulation, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 13/33] tcg: add options for enabling MTTCG, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 17/33] cpus: re-factor out handle_icount_deadline, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 22/33] atomic: introduce cmpxchg_bool, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 16/33] tcg: drop global lock during TCG code execution, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 18/33] tcg: remove global exit_request, Alex Bennée, 2016/10/27
- [Qemu-devel] [PATCH v5 15/33] tcg: rename tcg_current_cpu to tcg_current_rr_cpu, Alex Bennée, 2016/10/27