From: Marc Zyngier <marc.zyngier@arm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Jason Cooper <jason@lakedaemon.net>,
Thomas Gleixner <tglx@linutronix.de>,
Grzegorz Jaszczyk <jaz@semihalf.com>
Subject: Re: [PATCH 0/3] irqchip: GIC kexec/kdump improvement and workarounds
Date: Tue, 13 Mar 2018 18:35:07 +0000 [thread overview]
Message-ID: <72c7a6d2-a4c4-26b2-2982-c1d1ffb39b81@arm.com> (raw)
In-Reply-To: <20180313175156.gmncij4rnqcdl5ie@lakrids.cambridge.arm.com>
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.
> That would avoid some work (including pointer chasing on potentially
> corrupt memory) in the kernel that crashed, making it more likely that
> we get to the crashkernel intact...
Seems perfectly sensible to me.
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2018-03-13 18:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-13 17:21 [PATCH 0/3] irqchip: GIC kexec/kdump improvement and workarounds Marc Zyngier
2018-03-13 17:21 ` [PATCH 1/3] irqchip/gic-v2: Reset APRn registers at boot time Marc Zyngier
2018-03-13 17:21 ` [PATCH 2/3] irqchip/gic-v3: Reset APgRn " Marc Zyngier
2018-03-13 17:21 ` [PATCH 3/3] irqchip/gic-v3: Allow LPIs to be disabled from the command line Marc Zyngier
2018-03-15 14:58 ` Shanker Donthineni
2018-03-15 15:59 ` Marc Zyngier
2018-03-13 17:51 ` [PATCH 0/3] irqchip: GIC kexec/kdump improvement and workarounds Mark Rutland
2018-03-13 18:35 ` Marc Zyngier [this message]
2018-03-14 16:57 ` Mark Rutland
2018-03-14 17:11 ` Thomas Gleixner
2018-03-14 17:42 ` Marc Zyngier
2018-03-14 19:35 ` Thomas Gleixner
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