diff options
Diffstat (limited to 'exec.c')
| -rw-r--r-- | exec.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/exec.c b/exec.c index 93128fd19a..963b91a018 100644 --- a/exec.c +++ b/exec.c @@ -93,6 +93,11 @@ static MemoryRegion io_mem_unassigned; #endif +#ifdef TARGET_PAGE_BITS_VARY +int target_page_bits; +bool target_page_bits_decided; +#endif + struct CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus); /* current CPU in the current thread. It is only valid inside cpu_exec() */ @@ -102,8 +107,37 @@ __thread CPUState *current_cpu; 2 = Adaptive rate instruction counting. */ int use_icount; +bool set_preferred_target_page_bits(int bits) +{ + /* The target page size is the lowest common denominator for all + * the CPUs in the system, so we can only make it smaller, never + * larger. And we can't make it smaller once we've committed to + * a particular size. + */ +#ifdef TARGET_PAGE_BITS_VARY + assert(bits >= TARGET_PAGE_BITS_MIN); + if (target_page_bits == 0 || target_page_bits > bits) { + if (target_page_bits_decided) { + return false; + } + target_page_bits = bits; + } +#endif + return true; +} + #if !defined(CONFIG_USER_ONLY) +static void finalize_target_page_bits(void) +{ +#ifdef TARGET_PAGE_BITS_VARY + if (target_page_bits == 0) { + target_page_bits = TARGET_PAGE_BITS_MIN; + } + target_page_bits_decided = true; +#endif +} + typedef struct PhysPageEntry PhysPageEntry; struct PhysPageEntry { @@ -2807,6 +2841,14 @@ void cpu_register_map_client(QEMUBH *bh) void cpu_exec_init_all(void) { qemu_mutex_init(&ram_list.mutex); + /* The data structures we set up here depend on knowing the page size, + * so no more changes can be made after this point. + * In an ideal world, nothing we did before we had finished the + * machine setup would care about the target page size, and we could + * do this much later, rather than requiring board models to state + * up front what their requirements are. + */ + finalize_target_page_bits(); io_mem_init(); memory_map_init(); qemu_mutex_init(&map_client_list_lock); |