[PATCH 03/17] iommu/vt-d: Extend dmar_domain to support nested domain

Yi Liu
2023-02-09T04:34:13Z

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.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/iommu/intel/iommu.h | 35 ++++++++++++++++++++----
include/uapi/linux/iommufd.h | 53 ++++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 2e70265d4ceb..4fe74f217696 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -541,15 +541,38 @@ struct dmar_domain {
spinlock_t lock; /* Protect device tracking lists */
struct list_head devices; /* all devices' list */

- 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 {
+ /* 2-level page table the user domain nested */
+ struct dmar_domain *s2_domain;
+ /* user page table pointer (in GPA) */
+ unsigned long s1_pgtbl;
+ /* page table attributes */
+ struct iommu_hwpt_intel_vtd s1_cfg;
+ };
+ };

struct iommu_domain domain; /* generic domain data structure for
iommu core */
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 6cfe102f26f3..0867900494c9 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -407,4 +407,57 @@ struct iommu_device_info {
__u32 __reserved;
};
#define IOMMU_DEVICE_GET_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DEVICE_GET_INFO)
+
+/**
+ * enum iommu_hwpt_intel_vtd_flags - Intel VT-d stage-1 page
+ * table entry attributes
+ * @IOMMU_VTD_PGTBL_SRE: Supervisor request
+ * @IOMMU_VTD_PGTBL_EAFE: Extended access enable
+ * @IOMMU_VTD_PGTBL_PCD: Page-level cache disable
+ * @IOMMU_VTD_PGTBL_PWT: Page-level write through
+ * @IOMMU_VTD_PGTBL_EMTE: Extended mem type enable
+ * @IOMMU_VTD_PGTBL_CD: PASID-level cache disable
+ * @IOMMU_VTD_PGTBL_WPE: Write protect enable
+ */
+enum iommu_hwpt_intel_vtd_flags {
+ IOMMU_VTD_PGTBL_SRE = 1 << 0,
+ IOMMU_VTD_PGTBL_EAFE = 1 << 1,
+ IOMMU_VTD_PGTBL_PCD = 1 << 2,
+ IOMMU_VTD_PGTBL_PWT = 1 << 3,
+ IOMMU_VTD_PGTBL_EMTE = 1 << 4,
+ IOMMU_VTD_PGTBL_CD = 1 << 5,
+ IOMMU_VTD_PGTBL_WPE = 1 << 6,
+ IOMMU_VTD_PGTBL_LAST = 1 << 7,
+};
+
+/**
+ * struct iommu_hwpt_intel_vtd - Intel VT-d specific user-managed
+ * stage-1 page table info
+ * @flags: Combination of enum iommu_hwpt_intel_vtd_flags
+ * @pgtbl_addr: The base address of the user-managed stage-1 page table.
+ * @pat: Page attribute table data to compute effective memory type
+ * @emt: Extended memory type
+ * @addr_width: The address width of the untranslated addresses that are
+ * subjected to the user-managed stage-1 page table.
+ * @__reserved: Must be 0
+ *
+ * The Intel VT-d specific data for creating hw_pagetable to represent
+ * the user-managed stage-1 page table that is used in nested translation.
+ *
+ * In nested translation, the stage-1 page table locates in the address
+ * space that defined by the corresponding stage-2 page table. Hence the
+ * stage-1 page table base address value should not be higher than the
+ * maximum untranslated address of stage-2 page table.
+ *
+ * The paging level of the stage-1 page table should be compataible with
+ * the hardware iommu. Otherwise, the allocation would be failed.
+ */
+struct iommu_hwpt_intel_vtd {
+ __u64 flags;
+ __u64 pgtbl_addr;
+ __u32 pat;
+ __u32 emt;
+ __u32 addr_width;
+ __u32 __reserved;
+};
#endif
--
2.34.1