Re: [patch 1/4] vt-d: quirk for masking vtd spec errors to platform error handling logic

[Chris Wright <chrisw@sous-sol.org>]

* Suresh Siddha (suresh.b.siddha@intel.com) wrote:
> On platforms with Intel 7500 chipset, there were some reports of system
> hang/NMI's during kexec/kdump in the presence of interrupt-remapping enabled.
> 
> During kdump, there is a window where the devices might be still using old
> kernel's interrupt information, while the kdump kernel is coming up. This can
> cause vt-d faults as the interrupt configuration from the old kernel map to
> null IRTE entries in the new kernel etc. (with out interrupt-remapping enabled,
> we still have the same issue but in this case we will see benign spurious
> interrupt hit the new kernel).
> 
> Based on platform config settings, these platforms seem to generate NMI/SMI
> when a vt-d fault happens and there were reports that the resulting SMI causes
> the  system to hang.
> 
> Fix it by masking vt-d spec defined errors to platform error reporting logic.
> VT-d spec related errors are already handled by the VT-d OS code, so need to
> report the same erorr through other channels.
> 
> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>

Acked-by: Chris Wright <chrisw@sous-sol.org>