diff options
Diffstat (limited to 'exec.c')
| -rw-r--r-- | exec.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/exec.c b/exec.c index 4aaa14b075..731b79d2e4 100644 --- a/exec.c +++ b/exec.c @@ -197,6 +197,7 @@ typedef struct subpage_t { static void io_mem_init(void); static void memory_map_init(void); +static void tcg_log_global_after_sync(MemoryListener *listener); static void tcg_commit(MemoryListener *listener); static MemoryRegion io_mem_watch; @@ -905,6 +906,7 @@ void cpu_address_space_init(CPUState *cpu, int asidx, newas->cpu = cpu; newas->as = as; if (tcg_enabled()) { + newas->tcg_as_listener.log_global_after_sync = tcg_log_global_after_sync; newas->tcg_as_listener.commit = tcg_commit; memory_listener_register(&newas->tcg_as_listener, as); } @@ -3142,6 +3144,35 @@ void address_space_dispatch_free(AddressSpaceDispatch *d) g_free(d); } +static void do_nothing(CPUState *cpu, run_on_cpu_data d) +{ +} + +static void tcg_log_global_after_sync(MemoryListener *listener) +{ + CPUAddressSpace *cpuas; + + /* Wait for the CPU to end the current TB. This avoids the following + * incorrect race: + * + * vCPU migration + * ---------------------- ------------------------- + * TLB check -> slow path + * notdirty_mem_write + * write to RAM + * mark dirty + * clear dirty flag + * TLB check -> fast path + * read memory + * write to RAM + * + * by pushing the migration thread's memory read after the vCPU thread has + * written the memory. + */ + cpuas = container_of(listener, CPUAddressSpace, tcg_as_listener); + run_on_cpu(cpuas->cpu, do_nothing, RUN_ON_CPU_NULL); +} + static void tcg_commit(MemoryListener *listener) { CPUAddressSpace *cpuas; |