Re: [PATCH v5 6/9] irqchip/gic-v3: Parse and export virtual GIC information

Hanjun Guo
2016-04-13T10:09:41Z

Hi Shanker, Julien,

On 2016/4/11 23:25, Shanker Donthineni wrote:
> Hi Julien,
>
> On 04/11/2016 09:27 AM, Julien Grall wrote:
>> Hello Hanjun,
>>
>> On 11/04/16 06:27, Hanjun Guo wrote:
>>> On 2016/4/4 19:37, Julien Grall wrote:
>>>> +static void __init gic_acpi_setup_kvm_info(void)
>>>> +{
>>>> + int irq;
>>>> +
>>>> + if (!gic_acpi_collect_virt_info()) {
>>>> + pr_warn("Unable to get hardware information used for
>>>> virtualization\n");
>>>> + return;
>>>> + }
>>>> +
>>>> + gic_v3_kvm_info.type = GIC_V3;
>>>> +
>>>> + irq = acpi_register_gsi(NULL, acpi_data.maint_irq,
>>>> + acpi_data.maint_irq_mode,
>>>> + ACPI_ACTIVE_HIGH);
>>>> + if (irq <= 0)
>>>> + return;
>>>> +
>>>> + gic_v3_kvm_info.maint_irq = irq;
>>>> +
>>>> + if (acpi_data.vcpu_base) {
>>>
>>> Sorry, I'm not familiar with KVM, but I got a question here, will
>>> KVM works without valid vcpu_base in GICv3 mode?
>>
> Yes, KVM works without vcpu_base in GICv3 mode. The vcpu_base will be used
> for emulatingvGICv2 feature. The vGICv3 emulation isdone through the
> system registers.
>
>> vcpu_base is only required for supporting GICv2 on GICv3.
>>
> Yes, you are right,

Thanks for the clarify.

Hanjun