[PATCH v2 04/11] vfio: Move storage of allow_unsafe_interrupts to vfio_main.c

[Jason Gunthorpe]

This legacy module knob has become uAPI, when set on the vfio_iommu_type1
it disables some security protections in the iommu drivers. Move the
storage for this knob to vfio_main.c so that iommufd can access it too.

The may need enhancing as we learn more about how necessary
allow_unsafe_interrupts is in the current state of the world. If vfio
container is disabled then this option will not be available to the user.

Tested-by: Nicolin Chen <nicolinc at nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
---
 drivers/vfio/vfio.h             | 2 ++
 drivers/vfio/vfio_iommu_type1.c | 5 ++---
 drivers/vfio/vfio_main.c        | 3 +++
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/vfio/vfio.h b/drivers/vfio/vfio.h
index f95f4925b83bbd..54e5a8e0834ccb 100644
--- a/drivers/vfio/vfio.h
+++ b/drivers/vfio/vfio.h
@@ -130,4 +130,6 @@ extern bool vfio_noiommu __read_mostly;
 enum { vfio_noiommu = false };
 #endif
 
+extern bool vfio_allow_unsafe_interrupts;
+
 #endif
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 23c24fe98c00d4..186e33a006d314 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -44,9 +44,8 @@
 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson at redhat.com>"
 #define DRIVER_DESC     "Type1 IOMMU driver for VFIO"
 
-static bool allow_unsafe_interrupts;
 module_param_named(allow_unsafe_interrupts,
-		   allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
+		   vfio_allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(allow_unsafe_interrupts,
 		 "Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
 
@@ -2282,7 +2281,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 		    iommu_group_for_each_dev(iommu_group, (void *)IOMMU_CAP_INTR_REMAP,
 					     vfio_iommu_device_capable);
 
-	if (!allow_unsafe_interrupts && !msi_remap) {
+	if (!vfio_allow_unsafe_interrupts && !msi_remap) {
 		pr_warn("%s: No interrupt remapping support.  Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
 		       __func__);
 		ret = -EPERM;
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 8c2dcb481ae10b..e1fec1db6a3c93 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -51,6 +51,9 @@ static struct vfio {
 	struct ida			device_ida;
 } vfio;
 
+bool vfio_allow_unsafe_interrupts;
+EXPORT_SYMBOL_GPL(vfio_allow_unsafe_interrupts);
+
 static DEFINE_XARRAY(vfio_device_set_xa);
 static const struct file_operations vfio_group_fops;
 
-- 
2.38.1