IOMMUs that support nesting translation needs report the capability info
to userspace, e.g. the format of first level/stage paging structures.
This patch reports nesting info by DOMAIN_ATTR_NESTING. Caller can get
nesting info after setting DOMAIN_ATTR_NESTING.
v2 -> v3:
*) remvoe cap/ecap_mask in iommu_nesting_info.
*) reuse DOMAIN_ATTR_NESTING to get nesting info.
*) return an empty iommu_nesting_info for SMMU drivers per Jean'
suggestion.
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
CC: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Eric Auger <eric.auger@xxxxxxxxxx>
Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
drivers/iommu/arm-smmu-v3.c | 29 ++++++++++++++++++++--
drivers/iommu/arm-smmu.c | 29 ++++++++++++++++++++--
include/uapi/linux/iommu.h | 59 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index f578677..0c45d4d 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -3019,6 +3019,32 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
return group;
}
+static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
+ void *data)
+{
+ struct iommu_nesting_info *info = (struct iommu_nesting_info *) data;
+ u32 size;
+
+ if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
+ return -ENODEV;
+
+ size = sizeof(struct iommu_nesting_info);
+
+ /*
+ * if provided buffer size is not equal to the size, should
+ * return 0 and also the expected buffer size to caller.
+ */
+ if (info->size != size) {
+ info->size = size;
+ return 0;
+ }
+
+ /* report an empty iommu_nesting_info for now */
+ memset(info, 0x0, size);
+ info->size = size;
+ return 0;
+}
+
static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
enum iommu_attr attr, void *data)
{
@@ -3028,8 +3054,7 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
case IOMMU_DOMAIN_UNMANAGED:
switch (attr) {
case DOMAIN_ATTR_NESTING:
- *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
- return 0;
+ return arm_smmu_domain_nesting_info(smmu_domain, data);
default:
return -ENODEV;
}
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 243bc4c..908607d 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1506,6 +1506,32 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
return group;
}
+static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
+ void *data)
+{
+ struct iommu_nesting_info *info = (struct iommu_nesting_info *) data;
+ u32 size;
+
+ if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
+ return -ENODEV;
+
+ size = sizeof(struct iommu_nesting_info);
+
+ /*
+ * if provided buffer size is not equal to the size, should
+ * return 0 and also the expected buffer size to caller.
+ */
+ if (info->size != size) {
+ info->size = size;
+ return 0;
+ }
+
+ /* report an empty iommu_nesting_info for now */
+ memset(info, 0x0, size);
+ info->size = size;
+ return 0;
+}
+
static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
enum iommu_attr attr, void *data)
{
@@ -1515,8 +1541,7 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
case IOMMU_DOMAIN_UNMANAGED:
switch (attr) {
case DOMAIN_ATTR_NESTING:
- *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
- return 0;
+ return arm_smmu_domain_nesting_info(smmu_domain, data);
default:
return -ENODEV;
}
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
index 1afc661..898c99a 100644
--- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h
@@ -332,4 +332,63 @@ struct iommu_gpasid_bind_data {
} vendor;
};
+/*
+ * struct iommu_nesting_info - Information for nesting-capable IOMMU.
+ * user space should check it before using
+ * nesting capability.
+ *
+ * @size: size of the whole structure
+ * @format: PASID table entry format, the same definition with
+ * @format of struct iommu_gpasid_bind_data.
+ * @features: supported nesting features.
+ * @flags: currently reserved for future extension.
+ * @data: vendor specific cap info.
+ *
+ * +---------------+----------------------------------------------------+
+ * | feature | Notes |
+ * +===============+====================================================+
+ * | SYSWIDE_PASID | Kernel manages PASID in system wide, PASIDs used |
+ * | | in the system should be allocated by host kernel |
+ * +---------------+----------------------------------------------------+
+ * | BIND_PGTBL | bind page tables to host PASID, the PASID could |
+ * | | either be a host PASID passed in bind request or |
+ * | | default PASIDs (e.g. default PASID of aux-domain) |
+ * +---------------+----------------------------------------------------+
+ * | CACHE_INVLD | mandatory feature for nesting capable IOMMU |
+ * +---------------+----------------------------------------------------+
+ *
+ */
+struct iommu_nesting_info {
+ __u32 size;
+ __u32 format;
+ __u32 features;
+#define IOMMU_NESTING_FEAT_SYSWIDE_PASID (1 << 0)
+#define IOMMU_NESTING_FEAT_BIND_PGTBL (1 << 1)
+#define IOMMU_NESTING_FEAT_CACHE_INVLD (1 << 2)
+ __u32 flags;
+ __u8 data[];
+};
+
+/*
+ * struct iommu_nesting_info_vtd - Intel VT-d specific nesting info
+ *
+ *
+ * @flags: VT-d specific flags. Currently reserved for future
+ * extension.
+ * @addr_width: The output addr width of first level/stage translation
+ * @pasid_bits: Maximum supported PASID bits, 0 represents no PASID
+ * support.
+ * @cap_reg: Describe basic capabilities as defined in VT-d capability
+ * register.
+ * @ecap_reg: Describe the extended capabilities as defined in VT-d
+ * extended capability register.
+ */
+struct iommu_nesting_info_vtd {
+ __u32 flags;
+ __u16 addr_width;
+ __u16 pasid_bits;
+ __u64 cap_reg;
+ __u64 ecap_reg;
+};
+
#endif /* _UAPI_IOMMU_H */
--
2.7.4
