From mboxrd@z Thu Jan 1 00:00:00 1970 From: tglx@linutronix.de (Thomas Gleixner) Date: Wed, 14 Mar 2018 18:11:06 +0100 (CET) Subject: [PATCH 0/3] irqchip: GIC kexec/kdump improvement and workarounds In-Reply-To: <20180314165708.daoui66waxvicciq@lakrids.cambridge.arm.com> References: <20180313172103.24281-1-marc.zyngier@arm.com> <20180313175156.gmncij4rnqcdl5ie@lakrids.cambridge.arm.com> <72c7a6d2-a4c4-26b2-2982-c1d1ffb39b81@arm.com> <20180314165708.daoui66waxvicciq@lakrids.cambridge.arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, 14 Mar 2018, Mark Rutland wrote: > On Tue, Mar 13, 2018 at 06:35:07PM +0000, Marc Zyngier wrote: > > On 13/03/18 17:51, Mark Rutland wrote: > > > On Tue, Mar 13, 2018 at 05:21:00PM +0000, Marc Zyngier wrote: > > >> As kexec and kdump are getting used a bit more intensively, I've been > > >> made aware of a number of shortcomings. > > >> > > >> The main gripe is from folks trying to launch a kdump kernel from > > >> within an interrupt handler. If using EOImode==1, things work as > > >> expected. If using EOImode==0 (such as in a guest), the secondary > > >> kernel hangs as the previous interrupt hasn't been EOI'd, and the > > >> active priority is still set. The first two patches are addressing > > >> this situation for both GICv2 and GICv3 by reseting the APRs to their > > >> default value. > > > > > > As a more general thing, if irqchip drivers have state that needs to be > > > reset in their init code, can we live all this irqchip reset to the > > > crashdump kernel, and kill machine_kexec_mask_interrupts() entirely? > > > > We could, once we know for sure that all the potential irqchips have > > been fixed. Or we could just remove it immediately, and see what breaks. > > I would be very tempted to do the latter. 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? Thanks, tglx