Re: [PATCH v2] PCI/MSI: Don't touch MSI bits when the PCI device is disconnected

From: Keith Busch
Date: Thu Nov 08 2018 - 16:52:44 EST


On Thu, Nov 08, 2018 at 02:09:17PM -0600, Bjorn Helgaas wrote:
>
> I'm having second thoughts about this. One thing I'm uncomfortable
> with is that sprinkling pci_dev_is_disconnected() around feels ad hoc
> instead of systematic, in the sense that I don't know how we convince
> ourselves that this (and only this) is the correct place to put it.

You know how the kernel provides ZERO_PAGE, wouldn't it be cool if we
also had a ONES_PAGE and could remap all virtual addresses from a memory
mapped device to that page on an ungraceful disconnect? I do not know
how to accomplish that, so might just be crazy talk... But if it is
possible, that would be a pretty nifty way to solve this problem.