On Tue, 23 Nov 2021 at 17:10, Peter Maydell <peter.mayd...@linaro.org> wrote: > > In gicv3_redist_lpi_pending() we update cs->hpplpi to indicate the > new highest priority pending LPI after changing the requested LPI > pending bit. However the overall highest priority pending interrupt > information won't be updated unless we call gicv3_redist_update(). > We do that from the callsite in gicv3-redist_process_lpi(), but not > from the callsite in icc_activate_irq(). The effect is that when the > guest acknowledges an LPI by reading ICC_IAR1_EL1, we mark it as not > pending in the data structure but still leave it in cs->hppi so will > offer it to the guest again. > > The effect is that if we are using an emulated GICv3 and ITS and > using devices which use LPIs (ie PCI devices) then Linux will > complain "irq 54: nobody cared" and then hang (probably because the > stale bogus interrupt info meant we never tried to deliver some other > real interrupt).
Hmm; this is definitely a bug, but maybe it's not the cause of the symptoms listed above -- I've just seen them again even with this fix. I'll keep digging... -- PMM
