On 14/06/2017 06:48, Richard Henderson wrote:
>>
>> Commit e75449a3 ("target/aarch64: optimize indirect branches") causes
>> a regression by which aarch64 guests freeze under TCG with -smp > 1,
>> even with `-accel accel=tcg,thread=single' (i.e. MTTCG disabled).
>>
>> I isolated the problem to the MSR handler. This patch forces an exit
>> after the handler is executed, which fixes the regression.
>
> Why would that be? The cpu_get_tb_cpu_state within helper_lookup_tb_ptr
> is supposed to read the new state that the msr handler would have
> installed.
Could some of these cause an interrupt, or some other change in the
cpu_exec flow?
Thanks,
Paolo
