From: Valdis.Kletnieks@vt.edu
To: Youquan Song <youquan.song@intel.com>
Cc: linux-kernel@vger.kernel.org, david.woodhouse@intel.com,
akpm@linux-foundation.org, mingo@elte.hu, tglx@linutronix.de,
hpa@zytor.com, hpa@linux.intel.com, allen.m.kay@intel.com,
suresh.b.siddha@intel.com, rajesh.sankaran@intel.com,
asit.k.mallick@intel.com, kent.liu@intel.com,
Youquan Song <youquan.song@linux.intel.com>
Subject: Re: [PATCH v3] x86, vt-d: enable x2apic opt out
Date: Mon, 23 May 2011 22:18:41 -0400 [thread overview]
Message-ID: <7457.1306203521@localhost> (raw)
In-Reply-To: Your message of "Mon, 23 May 2011 22:32:28 +0800." <1306161148-3987-1-git-send-email-youquan.song@intel.com>
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On Mon, 23 May 2011 22:32:28 +0800, Youquan Song said:
> + no_x2apic_optout [Default Off]
> + With this option BIOS x2APIC opt-out request will be
> + ignored.
> + else if (!x2apic_supported() && cpu_has_x2apic)
> + WARN(1, "Your BIOS is broken and requested that x2apic be "
> + "disabled.\n This will leave your machine vulnerable to"
> + " irq-injection attacks\n"
> + "Use 'intel_iommu=no_x2apic_optout' to override BIOS "
> + "request\n");
If we're doing a WARN level here, what are the downsides of just automagically
forcing it rather than making them use a kernel parameter and reboot? Will
some systems fail to boot because the BIOS was in fact right in requesting
hat x2apic be turned off?
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next prev parent reply other threads:[~2011-05-24 2:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-23 14:32 [PATCH v3] x86, vt-d: enable x2apic opt out Youquan Song
2011-05-24 2:18 ` Valdis.Kletnieks [this message]
2011-05-24 15:36 ` Youquan Song
2011-05-24 4:18 ` Valdis.Kletnieks
2011-05-24 7:38 ` David Woodhouse
2011-05-24 12:13 ` Valdis.Kletnieks
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