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authorAlex Williamson <alex.williamson@redhat.com>2013-06-21 09:38:11 -0600
committerAlex Williamson <alex.williamson@redhat.com>2013-06-21 09:38:11 -0600
commit5c6c2b21ecc9adfc47cfaf93404937b6ecd8395d (patch)
treee1ca8d286dcb07f99113924c90188000c01b1ad4 /drivers/vfio
parent166fd7d94afdac040b28c473e45241820ca522a2 (diff)
downloadlinux-5c6c2b21ecc9adfc47cfaf93404937b6ecd8395d.tar.bz2
vfio: Provide module option to disable vfio_iommu_type1 hugepage support
Add a module option to vfio_iommu_type1 to disable IOMMU hugepage support. This causes iommu_map to only be called with single page mappings, disabling the IOMMU driver's ability to use hugepages. This option can be enabled by loading vfio_iommu_type1 with disable_hugepages=1 or dynamically through sysfs. If enabled dynamically, only new mappings are restricted. Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio_iommu_type1.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 6654a7eb42d3..8a2be4e40f22 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -48,6 +48,12 @@ module_param_named(allow_unsafe_interrupts,
MODULE_PARM_DESC(allow_unsafe_interrupts,
"Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
+static bool disable_hugepages;
+module_param_named(disable_hugepages,
+ disable_hugepages, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(disable_hugepages,
+ "Disable VFIO IOMMU support for IOMMU hugepages.");
+
struct vfio_iommu {
struct iommu_domain *domain;
struct mutex lock;
@@ -270,6 +276,11 @@ static long vfio_pin_pages(unsigned long vaddr, long npage,
return -ENOMEM;
}
+ if (unlikely(disable_hugepages)) {
+ vfio_lock_acct(1);
+ return 1;
+ }
+
/* Lock all the consecutive pages from pfn_base */
for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
unsigned long pfn = 0;