Messages in this thread | | | Date | Wed, 14 Mar 2018 20:35:29 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH 0/3] irqchip: GIC kexec/kdump improvement and workarounds |
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On Wed, 14 Mar 2018, Marc Zyngier wrote: > On 14/03/18 17:11, Thomas Gleixner wrote: > > Makes sense. Do we have any indicator that tells us that a particular irq > > chip is missing something in the init code or do we have to rely on crash > > reports? > A way to work out what is potentially missing would be to make sure that > whatever we're removing from machine_kexec_mask_interrupts, we can find > it in the irqchip init code. Not an easy task, and certainly not perfect > (patches 1 and 2 in this series have no equivalent in the kexec code). > > There is still another category of "reset" stuff that belongs to the > teardown path, and that's for things that may have an impact on the > secondary kernel. > > The case I have in mind is that of the GIC LPI pending tables. These are > allocated to the GIC, which can write pending bits at any time. Think of > it as a DMA engine. At the moment we enter the secondary kernel, we must > make sure the GIC has already been shut down, as the table memory will > be reallocated.
Yes, you surely need to prevent that.
Thanks,
tglx
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