Re: [PATCH 0/3] Support userspace irqchip with arch timers

[Alexander Graf <agraf@suse.de>]

On 30.09.16 17:43, Christoffer Dall wrote:
> On Fri, Sep 30, 2016 at 05:38:11PM +0200, Alexander Graf wrote:
>>
>>
>> On 30.09.16 16:54, Alexander Graf wrote:
>>>
>>>
>>> On 27.09.16 21:08, Christoffer Dall wrote:
>>>> Hi Alex,
>>>>
>>>> Marc and I have been looking at this during Linaro connect and have
>>>> slightly reworked your patch into this small series.
>>>>
>>>> It would be good if you could have a look at it and test it out.
>>>>
>>>> I've tested it with your QEMU, and it works for UP, but secondary CPUs
>>>> fail to come up, and it looks like the kernel never gets an IPI for
>>>> those CPUs from userspace.  Any chance you're willing to take a look at
>>>> that?
>>>
>>> I still need to see whether I can come up with a prettier solution, but
>>> for now this works:
>>>
>>> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
>>
>> Eh, no, not in i386 code :). But the problem seems to be a missing
>> mpstate sync.
>>
> Yeah, that looked really dodgy.  Have you tested it? :)

This time around tested with the correct command line parameters I hope
:). I'll send a pretty patch later.

diff --git a/target-arm/kvm.c b/target-arm/kvm.c
index b4c8fe2..b549f00 100644
--- a/target-arm/kvm.c
+++ b/target-arm/kvm.c
@@ -173,6 +173,12 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
      */
     kvm_async_interrupts_allowed = true;

+    /*
+     * PSCI wakes up secondary cores, so we always need to
+     * have vCPUs waiting in kernel space
+     */
+    kvm_halt_in_kernel_allowed = true;
+
     cap_has_mp_state = kvm_check_extension(s, KVM_CAP_MP_STATE);

     type_register_static(&host_arm_cpu_type_info);


Alex