Re: [PATCH] hw/nvme: Add iothread support

[Jinhao Fan]

at 10:45 PM, Keith Busch <kbusch@kernel.org> wrote:

> On Tue, Jul 26, 2022 at 04:55:54PM +0800, Jinhao Fan wrote:
>> Hi Klaus and Keith,
>> 
>> I just added support for interrupt masking. How can I test interrupt
>> masking?
> 
> Are you asking about MSI masking? I don't think any drivers are using the
> feature, so you'd need to modify one to test it. I can give you some pointers
> if you are asking about MSI.

Thanks Keith,

Do I understand correctly: qemu-nvme only supports MSI-X and pin-based
interrupts. So MSI masking here is equivalent with MSI-X masking.

If the above is correct, I think I am asking about MSI masking.

BTW, a double check on ctrl.c seems to show that we only support disabling
interrupt at CQ creation time, which is recorded in the cq->irq_enabled.
This is different from my prior understanding that interrupts can be
disabled at runtime by a call like Linux irq_save(). Therefore I doubt
whether qemu-nvme supported "interrupt masking" before. How do you
understand qemu-nvme’s interrupt masking support?

Jinhao