Re: [PATCH 7/9] virtio-pci: harden INTX interrupts

[Thomas Gleixner]

On Mon, Sep 13 2021 at 18:01, Michael S. Tsirkin wrote:
> On Mon, Sep 13, 2021 at 11:36:24PM +0200, Thomas Gleixner wrote:
>> >From the interrupt perspective the sequence:
>> 
>>         disable_irq();
>>         vp_dev->intx_soft_enabled = true;
>>         enable_irq();
>> 
>> is perfectly fine as well. Any interrupt arriving during the disabled
>> section will be reraised on enable_irq() in hardware because it's a
>> level interrupt. Any resulting failure is either a hardware or a
>> hypervisor bug.
>
> yes but it's a shared interrupt. what happens if multiple callers do
> this in parallel?

Nothing as each caller is serialized vs. itself and its own interrupt
handler it cares about.

Thanks,

        tglx