[RFC v4 10/14] vfio: introduce VFIO_IOVA_RESERVED vfio_dma type

From: Eric Auger
Date: Fri Feb 26 2016 - 12:38:20 EST


We introduce a vfio_dma type since we will need to discriminate
legacy vfio_dma's from new reserved ones. Since those latter are
not mapped at registration, some treatments need to be reworked:
removal, replay. Currently they are unplugged. In subsequent patches
they will be reworked.

Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
---
drivers/vfio/vfio_iommu_type1.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 6f1ea3d..692e9a2 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -53,6 +53,15 @@ module_param_named(disable_hugepages,
MODULE_PARM_DESC(disable_hugepages,
"Disable VFIO IOMMU support for IOMMU hugepages.");

+enum vfio_iova_type {
+ VFIO_IOVA_USER = 0, /* standard IOVA used to map user vaddr */
+ /*
+ * IOVA reserved to map special host physical addresses,
+ * MSI frames for instance
+ */
+ VFIO_IOVA_RESERVED,
+};
+
struct vfio_iommu {
struct list_head domain_list;
struct mutex lock;
@@ -75,6 +84,7 @@ struct vfio_dma {
unsigned long vaddr; /* Process virtual addr */
size_t size; /* Map size (bytes) */
int prot; /* IOMMU_READ/WRITE */
+ enum vfio_iova_type type; /* type of IOVA */
};

struct vfio_group {
@@ -395,7 +405,8 @@ static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)

static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
- vfio_unmap_unpin(iommu, dma);
+ if (likely(dma->type != VFIO_IOVA_RESERVED))
+ vfio_unmap_unpin(iommu, dma);
vfio_unlink_dma(iommu, dma);
kfree(dma);
}
@@ -671,6 +682,10 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
dma_addr_t iova;

dma = rb_entry(n, struct vfio_dma, node);
+
+ if (unlikely(dma->type == VFIO_IOVA_RESERVED))
+ continue;
+
iova = dma->iova;

while (iova < dma->iova + dma->size) {
--
1.9.1