From af8d102f999a41c0189bd2cce488bac2ee88c29b Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Fri, 1 Feb 2013 14:57:43 -0800 Subject: [PATCH] x86/intel/irq_remapping: Clean up x2apic opt-out security warning mess Current kernels print this on my Dell server: ------------[ cut here ]------------ WARNING: at drivers/iommu/intel_irq_remapping.c:542 intel_enable_irq_remapping+0x7b/0x27e() Hardware name: PowerEdge R620 Your BIOS is broken and requested that x2apic be disabled This will leave your machine vulnerable to irq-injection attacks Use 'intremap=no_x2apic_optout' to override BIOS request [...] Enabled IRQ remapping in xapic mode x2apic not enabled, IRQ remapping is in xapic mode This is inconsistent with itself -- interrupt remapping is *on*. Fix the mess by making the warnings say what they mean and my making sure that compatibility format interrupts (the dangerous ones) are disabled if x2apic is present regardless of BIOS settings. With this patch applied, the output is: Your BIOS is broken and requested that x2apic be disabled. This will slightly decrease performance. Use 'intremap=no_x2apic_optout' to override BIOS request. Enabled IRQ remapping in xapic mode x2apic not enabled, IRQ remapping is in xapic mode This should make us as or more secure than we are now and replace a rather scary warning with a much less scary warning on silly but functional systems. Signed-off-by: Andy Lutomirski Cc: Suresh Siddha Cc: Prarit Bhargava Cc: Gleb Natapov Cc: Don Zickus Cc: Alex Williamson Link: http://lkml.kernel.org/r/2011b943a886fd7c46079eb10bc24fc130587503.1359759303.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- Reading git-format-patch failed