iommu: Introduce guest PASID bind function

Guest shared virtual address (SVA) may require host to shadow guest
PASID tables. Guest PASID can also be allocated from the host via
enlightened interfaces. In this case, guest needs to bind the guest
mm, i.e. cr3 in guest physical address to the actual PASID table in
the host IOMMU. Nesting will be turned on such that guest virtual
address can go through a two level translation:
- 1st level translates GVA to GPA
- 2nd level translates GPA to HPA
This patch introduces APIs to bind guest PASID data to the assigned
device entry in the physical IOMMU. See the diagram below for usage
explanation.

    .-------------.  .---------------------------.
    |   vIOMMU    |  | Guest process mm, FL only |
    |             |  '---------------------------'
    .----------------/
    | PASID Entry |--- PASID cache flush -
    '-------------'                       |
    |             |                       V
    |             |                      GP
    '-------------'
Guest
------| Shadow |----------------------- GP->HP* ---------
      v        v                          |
Host                                      v
    .-------------.  .----------------------.
    |   pIOMMU    |  | Bind FL for GVA-GPA  |
    |             |  '----------------------'
    .----------------/  |
    | PASID Entry |     V (Nested xlate)
    '----------------\.---------------------.
    |             |   |Set SL to GPA-HPA    |
    |             |   '---------------------'
    '-------------'

Where:
 - FL = First level/stage one page tables
 - SL = Second level/stage two page tables
 - GP = Guest PASID
 - HP = Host PASID
* Conversion needed if non-identity GP-HP mapping option is chosen.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 9b22055e6f85..f8959f759e41 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -13,6 +13,7 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/of.h>
+#include <linux/ioasid.h>
 #include <uapi/linux/iommu.h>
 
 #define IOMMU_READ	(1 << 0)
@@ -246,6 +247,8 @@ struct iommu_iotlb_gather {
  * @page_response: handle page request response
  * @cache_invalidate: invalidate translation caches
  * @pgsize_bitmap: bitmap of all possible supported page sizes
+ * @sva_bind_gpasid: bind guest pasid and mm
+ * @sva_unbind_gpasid: unbind guest pasid and mm
  */
 struct iommu_ops {
 	bool (*capable)(enum iommu_cap);
@@ -309,6 +312,10 @@ struct iommu_ops {
 			     struct iommu_page_response *msg);
 	int (*cache_invalidate)(struct iommu_domain *domain, struct device *dev,
 				struct iommu_cache_invalidate_info *inv_info);
+	int (*sva_bind_gpasid)(struct iommu_domain *domain,
+			struct device *dev, struct iommu_gpasid_bind_data *data);
+
+	int (*sva_unbind_gpasid)(struct device *dev, int pasid);
 
 	unsigned long pgsize_bitmap;
 };
@@ -423,6 +430,10 @@ extern void iommu_detach_device(struct iommu_domain *domain,
 extern int iommu_cache_invalidate(struct iommu_domain *domain,
 				  struct device *dev,
 				  struct iommu_cache_invalidate_info *inv_info);
+extern int iommu_sva_bind_gpasid(struct iommu_domain *domain,
+		struct device *dev, struct iommu_gpasid_bind_data *data);
+extern int iommu_sva_unbind_gpasid(struct iommu_domain *domain,
+				struct device *dev, ioasid_t pasid);
 extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev);
 extern struct iommu_domain *iommu_get_dma_domain(struct device *dev);
 extern int iommu_map(struct iommu_domain *domain, unsigned long iova,
@@ -1018,6 +1029,17 @@ iommu_cache_invalidate(struct iommu_domain *domain,
 {
 	return -ENODEV;
 }
+static inline int iommu_sva_bind_gpasid(struct iommu_domain *domain,
+				struct device *dev, struct iommu_gpasid_bind_data *data)
+{
+	return -ENODEV;
+}
+
+static inline int iommu_sva_unbind_gpasid(struct iommu_domain *domain,
+					   struct device *dev, int pasid)
+{
+	return -ENODEV;
+}
 
 #endif /* CONFIG_IOMMU_API */