Re: [PATCH 6/8] hvf: Use OS provided vcpu kick function

[Claudio Fontana]

On 11/30/20 3:42 AM, Alexander Graf wrote:
> 
> On 26.11.20 23:18, Eduardo Habkost wrote:
>> On Thu, Nov 26, 2020 at 10:50:15PM +0100, Alexander Graf wrote:
>>> When kicking another vCPU, we get an OS function that explicitly does that 
>>> for us
>>> on Apple Silicon. That works better than the current signaling logic, let's 
>>> make
>>> use of it there.
>>>
>>> Signed-off-by: Alexander Graf <agraf@csgraf.de>
>>> ---
>>>   accel/hvf/hvf-cpus.c | 12 ++++++++++++
>>>   1 file changed, 12 insertions(+)
>>>
>>> diff --git a/accel/hvf/hvf-cpus.c b/accel/hvf/hvf-cpus.c
>>> index b9f674478d..74a272d2e8 100644
>>> --- a/accel/hvf/hvf-cpus.c
>>> +++ b/accel/hvf/hvf-cpus.c
>>> @@ -418,8 +418,20 @@ static void hvf_start_vcpu_thread(CPUState *cpu)
>>>                          cpu, QEMU_THREAD_JOINABLE);
>>>   }
>>>   
>>> +#ifdef __aarch64__
>>> +static void hvf_kick_vcpu_thread(CPUState *cpu)
>>> +{
>>> +    if (!qemu_cpu_is_self(cpu)) {
>>> +        hv_vcpus_exit(&cpu->hvf_fd, 1);
>>> +    }
>>> +}
>>> +#endif
>>> +
>>>   static const CpusAccel hvf_cpus = {
>>>       .create_vcpu_thread = hvf_start_vcpu_thread,
>>> +#ifdef __aarch64__
>>> +    .kick_vcpu_thread = hvf_kick_vcpu_thread,
>>> +#endif
>> Interesting.  We have considered the possibility of adding
>> arch-specific TYPE_ACCEL subclasses when discussing Claudio's,
>> series.  Here we have another arch-specific hack that could be
>> avoided if we had a TYPE_ARM_HVF_ACCEL QOM class.
> 
> 
> I don't think that's necessary in this case. I don't see how you could 
> ever have aarch64 and x86 HVF backends compiled into the same binary. 
> The header files even have a lot of #ifdef's.
> 
> Either way, I've changed it to a weak function in v2. That way it's a 
> bit easier to read.
> 
> 
> Alex
> 
> 

Ciao Alex!

you're in the news, congrats for your hack!

Ciao,

Claudio