[RFC PATCH 7/8] VFIO: Add new IOCTL for IOMMU TLB invalidate propagation

["Liu, Yi L" <yi.l.liu@intel.com>]

From: "Liu, Yi L" <yi.l.liu@linux.intel.com>

This patch adds VFIO_IOMMU_TLB_INVALIDATE to propagate IOMMU TLB
invalidate request from guest to host.

In the case of SVM virtualization on VT-d, host IOMMU driver has
no knowledge of caching structure updates unless the guest
invalidation activities are passed down to the host. So a new
IOCTL is needed to propagate the guest cache invalidation through
VFIO.

Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com>
---
 include/uapi/linux/vfio.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 6b97987..50c51f8 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -564,6 +564,15 @@ struct vfio_device_svm {
 
 #define VFIO_IOMMU_SVM_BIND_TASK	_IO(VFIO_TYPE, VFIO_BASE + 22)
 
+/* For IOMMU TLB Invalidation Propagation */
+struct vfio_iommu_tlb_invalidate {
+	__u32	argsz;
+	__u32	length;
+	__u8	data[];
+};
+
+#define VFIO_IOMMU_TLB_INVALIDATE	_IO(VFIO_TYPE, VFIO_BASE + 23)
+
 /* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */
 
 /*
-- 
1.9.1