Frederic Konrad <fred.kon...@greensocs.com> writes:
> On 10/08/2015 17:27, fred.kon...@greensocs.com wrote:
>> From: KONRAD Frederic <fred.kon...@greensocs.com>
>>
>> This protects TBContext with tb_lock to make tb_* thread safe.
>>
>> We can still have issue with tb_flush in case of multithread TCG:
>> An other CPU can be executing code during a flush.
>>
>> This can be fixed later by making all other TCG thread exiting before calling
>> tb_flush().
>>
>> tb_find_slow is separated into tb_find_slow and tb_find_physical as the whole
>> tb_find_slow doesn't require to lock the tb.
>>
>> Signed-off-by: KONRAD Frederic <fred.kon...@greensocs.com>
>>
>> Changes:
> [...]
>>
>> @@ -675,6 +710,7 @@ static inline void code_gen_alloc(size_t tb_size)
>> CODE_GEN_AVG_BLOCK_SIZE;
>> tcg_ctx.tb_ctx.tbs =
>> g_malloc(tcg_ctx.code_gen_max_blocks *
>> sizeof(TranslationBlock));
>> + qemu_mutex_init(&tcg_ctx.tb_ctx.tb_lock);
>> }
>>
>> /* Must be called before using the QEMU cpus. 'tb_size' is the size
>> @@ -699,16 +735,22 @@ bool tcg_enabled(void)
>> return tcg_ctx.code_gen_buffer != NULL;
>> }
>>
>> -/* Allocate a new translation block. Flush the translation buffer if
>> - too many translation blocks or too much generated code. */
>> +/*
>> + * Allocate a new translation block. Flush the translation buffer if
>> + * too many translation blocks or too much generated code.
>> + * tb_alloc is not thread safe but tb_gen_code is protected by a mutex so
>> this
>> + * function is called only by one thread.
>> + */
>> static TranslationBlock *tb_alloc(target_ulong pc)
>> {
>> - TranslationBlock *tb;
>> + TranslationBlock *tb = NULL;
>>
>> if (tcg_ctx.tb_ctx.nb_tbs >= tcg_ctx.code_gen_max_blocks ||
>> (tcg_ctx.code_gen_ptr - tcg_ctx.code_gen_buffer) >=
>> tcg_ctx.code_gen_buffer_max_size) {
>> - return NULL;
>> + tb = &tcg_ctx.tb_ctx.tbs[tcg_ctx.tb_ctx.nb_tbs++];
>> + tb->pc = pc;
>> + tb->cflags = 0;
>
> Missed this wrong unreverted part which in the end doesn't do a tb_flush
> when required and crashes!
> Fixing that allows me to boot with jessie and virt.
\o/
Do you see crashes while it is running?
It's interesting that I've not had a problem booting jessie with virt
though - just crashes while hanging.
Are you likely to push a v8 this week (or a temp branch?) with this and
any other obvious fixes? I appreciate Paolo has given you a not-so-small
pile of review comments as well so I wasn't looking for a complete new
patch set!
>
> Fred
--
Alex Bennée
