[PATCH v8 2/8] iommu/vt-d: Extend dmar_domain to support nested domain

Yi Liu
2023-10-26T04:43:15Z

From: Lu Baolu <baolu.lu@linux.intel.com>

The nested domain fields are exclusive to those that used for a DMA
remapping domain. Use union to avoid memory waste.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/intel/iommu.h | 36 ++++++++++++++++++++++++++++++------
1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index cc7301579773..244f111ea0bb 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -25,6 +25,7 @@

#include <asm/cacheflush.h>
#include <asm/iommu.h>
+#include <uapi/linux/iommufd.h>

/*
* VT-d hardware uses 4KiB page size regardless of host page size.
@@ -605,15 +606,38 @@ struct dmar_domain {
struct list_head devices; /* all devices' list */
struct list_head dev_pasids; /* all attached pasids */

- struct dma_pte *pgd; /* virtual address */
- int gaw; /* max guest address width */
-
- /* adjusted guest address width, 0 is level 2 30-bit */
- int agaw;
int iommu_superpage;/* Level of superpages supported:
0 == 4KiB (no superpages), 1 == 2MiB,
2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
- u64 max_addr; /* maximum mapped address */
+ union {
+ /* DMA remapping domain */
+ struct {
+ /* virtual address */
+ struct dma_pte *pgd;
+ /* max guest address width */
+ int gaw;
+ /*
+ * adjusted guest address width:
+ * 0: level 2 30-bit
+ * 1: level 3 39-bit
+ * 2: level 4 48-bit
+ * 3: level 5 57-bit
+ */
+ int agaw;
+ /* maximum mapped address */
+ u64 max_addr;
+ };
+
+ /* Nested user domain */
+ struct {
+ /* parent page table which the user domain is nested on */
+ struct dmar_domain *s2_domain;
+ /* user page table pointer (in GPA) */
+ unsigned long s1_pgtbl;
+ /* page table attributes */
+ struct iommu_hwpt_vtd_s1 s1_cfg;
+ };
+ };

struct iommu_domain domain; /* generic domain data structure for
iommu core */
--
2.34.1