Commit 4f506e07 authored Mar 25, 2010 by Arnaud Patard Committed by David Woodhouse Apr 14, 2010

intel-iommu: Fix boot inside 64bit virtualbox with io-apic disabled



Commit 074835f0 ("intel-iommu: Fix
kernel hand if interrupt remapping disabled in BIOS") is adding a check
for interrupt remapping disabled and is dereferencing the dmar_tbl
pointer without checking its value.

Unfortunately, this value is null when booting inside a 64bit virtual
box guest with io-apic disabled, leading to a crash. With a check on it,
the guest is now booting. It's triggering a WARN() in
clockevent_delta2ns but it's better than not booting at all and allows
the user to see there's something wrong on their io-apic setup.

Signed-off-by: Arnaud Patard <apatard@mandriva.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

parent dda56549

drivers/pci/dmar.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1466,5 +1466,7 @@ int __init dmar_ir_support(void)
		{
		struct acpi_table_dmar *dmar;
		dmar = (struct acpi_table_dmar *)dmar_tbl;
		if (!dmar)
		return 0;
		return dmar->flags & 0x1;
		}

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