Messages in this thread | | | Subject | Re: [RFT PATCH v3 16/27] irqchip/apple-aic: Add support for the Apple Interrupt Controller | From | Hector Martin <> | Date | Fri, 26 Mar 2021 16:57:29 +0900 |
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On 08/03/2021 22.31, Marc Zyngier wrote: >> + if ((read_sysreg_s(SYS_ICH_HCR_EL2) & ICH_HCR_EN) && >> + read_sysreg_s(SYS_ICH_MISR_EL2) != 0) { >> + pr_err("vGIC IRQ fired, disabling.\n"); > > Please add a _ratelimited here. Whilst debugging KVM on this machine, > I ended up with this firing at such a rate that it was impossible to > do anything useful. Ratelimiting it allowed me to pinpoint the > problem.
Ouch. Done for v4.
>> +static void aic_fiq_eoi(struct irq_data *d) >> +{ >> + /* We mask to ack (where we can), so we need to unmask at EOI. */ >> + if (!irqd_irq_disabled(d) && !irqd_irq_masked(d)) > > Ah, be careful here: irqd_irq_masked() doesn't do what you think it > does for per-CPU interrupts. It's been on my list to fix for the rVIC > implementation, but I never got around to doing it, and all decent ICs > hide this from SW by having a HW-managed mask, similar to what is on > the IRQ side. > > I can see two possibilities: > > - you can track the masked state directly and use that instead of > these predicates > > - you can just drop the masking altogether as this is only useful to a > hosted hypervisor (KVM), which will have to do its own masking > behind the scenes anyway >
Since you're using the masking in KVM after all, I'm tracking the mask state in a percpu variable now. Also folded in your two minor bugfixes from the KVM series. Cheers!
-- Hector Martin (marcan@marcan.st) Public Key: https://mrcn.st/pub
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