Re: [PATCH v4 3/9] KVM: arm64: vgic: Be tolerant to the lack of maintenance interrupt masking

[Alexandru Elisei <alexandru.elisei@arm.com>]

Hi Marc,

On 6/11/21 5:38 PM, Alexandru Elisei wrote:
> Hi Marc,
>
> On 6/1/21 11:39 AM, Marc Zyngier wrote:
>> As it turns out, not all the interrupt controllers are able to
>> expose a vGIC maintenance interrupt that can be independently
>> enabled/disabled.
>>
>> And to be fair, it doesn't really matter as all we require is
>> for the interrupt to kick us out of guest mode out way or another.
>>
>> To that effect, add gic_kvm_info.no_maint_irq_mask for an interrupt
>> controller to advertise the lack of masking.
>>
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
>> ---
>>  arch/arm64/kvm/vgic/vgic-init.c       | 8 +++++++-
>>  include/linux/irqchip/arm-vgic-info.h | 2 ++
>>  2 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
>> index 2fdb65529594..6752d084934d 100644
>> --- a/arch/arm64/kvm/vgic/vgic-init.c
>> +++ b/arch/arm64/kvm/vgic/vgic-init.c
>> @@ -519,12 +519,15 @@ void kvm_vgic_init_cpu_hardware(void)
>>   */
>>  int kvm_vgic_hyp_init(void)
>>  {
>> +	bool has_mask;
>>  	int ret;
>>  
>>  	if (!gic_kvm_info)
>>  		return -ENODEV;
>>  
>> -	if (!gic_kvm_info->maint_irq) {
>> +	has_mask = !gic_kvm_info->no_maint_irq_mask;
> This double negative is pretty awkward, I suppose this was done to avoid changes
> to the gic drivers, because the default value is 0 (false). Just an idea, maybe
> renaming it to maint_irq_unmaskable would be more readable?

Actually, after another look, the current name stopped looking awkward to me.

Thanks,

Alex

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