Date: Tue, 30 Nov 2010 23:26:54 -0800
From: Chris Wright <chrisw@sous-sol.org>
To: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org,
        Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>,
        Chris Wright <chrisw@sous-sol.org>,
        Max Asbock <masbock@linux.vnet.ibm.com>, indou.takao@jp.fujitsu.com,
        Jesse Barnes <jbarnes@virtuousgeek.org>,
        Bjorn Helgaas <bjorn.helgaas@hp.com>,
        David Woodhouse <dwmw2@infradead.org>, stable@kernel.org
Subject: Re: [patch 1/4] vt-d: quirk for masking vtd spec errors to platform
 error handling logic
Message-ID: <20101201072654.GL10050@sequoia.sous-sol.org>
References: <20101201062225.292364637@intel.com>
 <20101201062244.365995600@intel.com>
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* 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>
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