[PATCH v3 09/10] iommu/vt-d: Implement hw_info for iommu capability query

Yi Liu
2023-05-11T14:53:23Z

Add intel_iommu_hw_info() to report cap_reg and ecap_reg information.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/iommu/intel/iommu.c | 19 +++++++++++++++++++
include/uapi/linux/iommufd.h | 23 +++++++++++++++++++++++
2 files changed, 42 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 51612da4a1ea..20d4ae1cb8a6 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4746,6 +4746,23 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
intel_pasid_tear_down_entry(iommu, dev, pasid, false);
}

+static void *intel_iommu_hw_info(struct device *dev, u32 *length)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct intel_iommu *iommu = info->iommu;
+ struct iommu_hw_info_vtd *vtd;
+
+ vtd = kzalloc(sizeof(*vtd), GFP_KERNEL);
+ if (!vtd)
+ return ERR_PTR(-ENOMEM);
+
+ vtd->cap_reg = iommu->cap;
+ vtd->ecap_reg = iommu->ecap;
+ *length = sizeof(*vtd);
+
+ return vtd;
+}
+
static int intel_iommu_domain_user_data_len(u32 hwpt_type)
{
if (hwpt_type != IOMMU_HWPT_TYPE_VTD_S1)
@@ -4755,6 +4772,7 @@ static int intel_iommu_domain_user_data_len(u32 hwpt_type)

const struct iommu_ops intel_iommu_ops = {
.capable = intel_iommu_capable,
+ .hw_info = intel_iommu_hw_info,
.domain_alloc = intel_iommu_domain_alloc,
.domain_alloc_user = intel_iommu_domain_alloc_user,
.domain_alloc_user_data_len = intel_iommu_domain_user_data_len,
@@ -4769,6 +4787,7 @@ const struct iommu_ops intel_iommu_ops = {
.def_domain_type = device_def_domain_type,
.remove_dev_pasid = intel_iommu_remove_dev_pasid,
.pgsize_bitmap = SZ_4K,
+ .hw_info_type = IOMMU_HW_INFO_TYPE_INTEL_VTD,
#ifdef CONFIG_INTEL_IOMMU_SVM
.page_response = intel_svm_page_response,
#endif
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 2e658fa346ad..b46270a4cf46 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -464,9 +464,32 @@ struct iommu_hwpt_alloc {

/**
* enum iommu_hw_info_type - IOMMU Hardware Info Types
+ * @IOMMU_HW_INFO_TYPE_INTEL_VTD: Intel VT-d iommu info type
*/
enum iommu_hw_info_type {
IOMMU_HW_INFO_TYPE_NONE,
+ IOMMU_HW_INFO_TYPE_INTEL_VTD,
+};
+
+/**
+ * struct iommu_hw_info_vtd - Intel VT-d hardware information
+ *
+ * @flags: Must be 0
+ * @__reserved: Must be 0
+ *
+ * @cap_reg: Value of Intel VT-d capability register defined in VT-d spec
+ * section 11.4.2 Capability Register.
+ * @ecap_reg: Value of Intel VT-d capability register defined in VT-d spec
+ * section 11.4.3 Extended Capability Register.
+ *
+ * User needs to understand the Intel VT-d specification to decode the
+ * register value.
+ */
+struct iommu_hw_info_vtd {
+ __u32 flags;
+ __u32 __reserved;
+ __aligned_u64 cap_reg;
+ __aligned_u64 ecap_reg;
};

/**
--
2.34.1