Re: [PATCH] iommu/vt-d: Ratelimit fault handler

From: David Woodhouse
Date: Tue Mar 15 2016 - 15:49:07 EST

On Tue, 2016-03-15 at 10:35 -0600, Alex Williamson wrote:
> Fault rates can easily overwhelm the console and make the system
> unresponsive. Ratelimit to allow an opportunity for maintenance.
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>

Rather than just rate-limiting the printk, I'd prefer to handle this
explicitly. There's a bit in the context-entry which can tell the IOMMU
not to bother raising an interrupt at all. And then we can re-enable it
if/when the driver recovers the device. (Or perhaps just when it next
does a mapping).

We really ought to be reporting faults to drivers too, FWIW. I keep
meaning to take a look at that.

David Woodhouse Open Source Technology Centre
David.Woodhouse@xxxxxxxxx Intel Corporation

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