x86: disable intel_iommu support by default
Due to recurring issues with DMAR support on certain platforms.
There's a number of filesystem corruption incidents reported:
https://bugzilla.redhat.com/show_bug.cgi?id=479996
http://bugzilla.kernel.org/show_bug.cgi?id=12578
Provide a Kconfig option to change whether it is enabled by
default.
If disabled, it can still be reenabled by passing intel_iommu=on to the
kernel. Keep the .config option off by default.
Signed-off-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-By: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3dfecb2..f4b7c79 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -268,7 +268,12 @@
static void domain_remove_dev_info(struct dmar_domain *domain);
-int dmar_disabled;
+#ifdef CONFIG_DMAR_DEFAULT_ON
+int dmar_disabled = 0;
+#else
+int dmar_disabled = 1;
+#endif /*CONFIG_DMAR_DEFAULT_ON*/
+
static int __initdata dmar_map_gfx = 1;
static int dmar_forcedac;
static int intel_iommu_strict;
@@ -284,9 +289,12 @@
if (!str)
return -EINVAL;
while (*str) {
- if (!strncmp(str, "off", 3)) {
+ if (!strncmp(str, "on", 2)) {
+ dmar_disabled = 0;
+ printk(KERN_INFO "Intel-IOMMU: enabled\n");
+ } else if (!strncmp(str, "off", 3)) {
dmar_disabled = 1;
- printk(KERN_INFO"Intel-IOMMU: disabled\n");
+ printk(KERN_INFO "Intel-IOMMU: disabled\n");
} else if (!strncmp(str, "igfx_off", 8)) {
dmar_map_gfx = 0;
printk(KERN_INFO