PASID usage requires PASID support in both device and IOMMU. Since the
iommu drivers always enable the PASID capability for the device if it
is supported, this extends the IOMMU_GET_HW_INFO to report the PASID
capability to userspace. Also, enhances the selftest accordingly.
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Tested-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxx> #aarch64 platform
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
drivers/iommu/iommufd/device.c | 35 +++++++++++++++++++++++++++++++++-
drivers/pci/ats.c | 33 ++++++++++++++++++++++++++++++++
include/linux/pci-ats.h | 3 +++
include/uapi/linux/iommufd.h | 14 +++++++++++++-
4 files changed, 83 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index afba66211b11..61fa16a6eddc 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -3,6 +3,8 @@
*/
#include <linux/iommu.h>
#include <linux/iommufd.h>
+#include <linux/pci.h>
+#include <linux/pci-ats.h>
#include <linux/slab.h>
#include <uapi/linux/iommufd.h>
@@ -1333,7 +1335,8 @@ int iommufd_get_hw_info(struct iommufd_ucmd *ucmd)
void *data;
int rc;
- if (cmd->flags || cmd->__reserved)
+ if (cmd->flags || cmd->__reserved[0] || cmd->__reserved[1] ||
+ cmd->__reserved[2])
return -EOPNOTSUPP;
idev = iommufd_get_device(ucmd, cmd->dev_id);
@@ -1390,6 +1393,36 @@ int iommufd_get_hw_info(struct iommufd_ucmd *ucmd)
if (device_iommu_capable(idev->dev, IOMMU_CAP_DIRTY_TRACKING))
cmd->out_capabilities |= IOMMU_HW_CAP_DIRTY_TRACKING;
+ cmd->out_max_pasid_log2 = 0;
+ /*
+ * Currently, all iommu drivers enable PASID in the probe_device()
+ * op if iommu and device supports it. So the max_pasids stored in
+ * dev->iommu indicates both PASID support and enable status. A
+ * non-zero dev->iommu->max_pasids means PASID is supported and
+ * enabled. The iommufd only reports PASID capability to userspace
+ * if it's enabled.
+ */
+ if (idev->dev->iommu->max_pasids) {
+ cmd->out_max_pasid_log2 = ilog2(idev->dev->iommu->max_pasids);
+
+ if (dev_is_pci(idev->dev)) {
+ struct pci_dev *pdev = to_pci_dev(idev->dev);
+ int ctrl;
+
+ ctrl = pci_pasid_status(pdev);
+
+ WARN_ON_ONCE(ctrl < 0 ||
+ !(ctrl & PCI_PASID_CTRL_ENABLE));
+
+ if (ctrl & PCI_PASID_CTRL_EXEC)
+ cmd->out_capabilities |=
+ IOMMU_HW_CAP_PCI_PASID_EXEC;
+ if (ctrl & PCI_PASID_CTRL_PRIV)
+ cmd->out_capabilities |=
+ IOMMU_HW_CAP_PCI_PASID_PRIV;
+ }
+ }
+
rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
out_free:
kfree(data);
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index c6b266c772c8..ec6c8dbdc5e9 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -538,4 +538,37 @@ int pci_max_pasids(struct pci_dev *pdev)
return (1 << FIELD_GET(PCI_PASID_CAP_WIDTH, supported));
}
EXPORT_SYMBOL_GPL(pci_max_pasids);
+
+/**
+ * pci_pasid_status - Check the PASID status
+ * @pdev: PCI device structure
+ *
+ * Returns a negative value when no PASID capability is present.
+ * Otherwise the value of the control register is returned.
+ * Status reported are:
+ *
+ * PCI_PASID_CTRL_ENABLE - PASID enabled
+ * PCI_PASID_CTRL_EXEC - Execute permission enabled
+ * PCI_PASID_CTRL_PRIV - Privileged mode enabled
+ */
+int pci_pasid_status(struct pci_dev *pdev)
+{
+ int pasid;
+ u16 ctrl;
+
+ if (pdev->is_virtfn)
+ pdev = pci_physfn(pdev);
+
+ pasid = pdev->pasid_cap;
+ if (!pasid)
+ return -EINVAL;
+
+ pci_read_config_word(pdev, pasid + PCI_PASID_CTRL, &ctrl);
+
+ ctrl &= PCI_PASID_CTRL_ENABLE | PCI_PASID_CTRL_EXEC |
+ PCI_PASID_CTRL_PRIV;
+
+ return ctrl;
+}
+EXPORT_SYMBOL_GPL(pci_pasid_status);
#endif /* CONFIG_PCI_PASID */
diff --git a/include/linux/pci-ats.h b/include/linux/pci-ats.h
index 0e8b74e63767..75c6c86cf09d 100644
--- a/include/linux/pci-ats.h
+++ b/include/linux/pci-ats.h
@@ -42,6 +42,7 @@ int pci_enable_pasid(struct pci_dev *pdev, int features);
void pci_disable_pasid(struct pci_dev *pdev);
int pci_pasid_features(struct pci_dev *pdev);
int pci_max_pasids(struct pci_dev *pdev);
+int pci_pasid_status(struct pci_dev *pdev);
#else /* CONFIG_PCI_PASID */
static inline int pci_enable_pasid(struct pci_dev *pdev, int features)
{ return -EINVAL; }
@@ -50,6 +51,8 @@ static inline int pci_pasid_features(struct pci_dev *pdev)
{ return -EINVAL; }
static inline int pci_max_pasids(struct pci_dev *pdev)
{ return -EINVAL; }
+static inline int pci_pasid_status(struct pci_dev *pdev)
+{ return -EINVAL; }
#endif /* CONFIG_PCI_PASID */
#endif /* LINUX_PCI_ATS_H */
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 78747b24bd0f..c842ad7d0fd8 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -608,9 +608,17 @@ enum iommu_hw_info_type {
* IOMMU_HWPT_GET_DIRTY_BITMAP
* IOMMU_HWPT_SET_DIRTY_TRACKING
*
+ * @IOMMU_HW_CAP_PASID_EXEC: Execute Permission Supported, user ignores it
+ * when the struct iommu_hw_info::out_max_pasid_log2
+ * is zero.
+ * @IOMMU_HW_CAP_PASID_PRIV: Privileged Mode Supported, user ignores it
+ * when the struct iommu_hw_info::out_max_pasid_log2
+ * is zero.
*/
enum iommufd_hw_capabilities {
IOMMU_HW_CAP_DIRTY_TRACKING = 1 << 0,
+ IOMMU_HW_CAP_PCI_PASID_EXEC = 1 << 1,
+ IOMMU_HW_CAP_PCI_PASID_PRIV = 1 << 2,
};
/**
@@ -626,6 +634,9 @@ enum iommufd_hw_capabilities {
* iommu_hw_info_type.
* @out_capabilities: Output the generic iommu capability info type as defined
* in the enum iommu_hw_capabilities.
+ * @out_max_pasid_log2: Output the width of PASIDs. 0 means no PASID support.
+ * PCI devices turn to out_capabilities to check if the
+ * specific capabilities is supported or not.
* @__reserved: Must be 0
*
* Query an iommu type specific hardware information data from an iommu behind
@@ -649,7 +660,8 @@ struct iommu_hw_info {
__u32 data_len;
__aligned_u64 data_uptr;
__u32 out_data_type;
- __u32 __reserved;
+ __u8 out_max_pasid_log2;
+ __u8 __reserved[3];
__aligned_u64 out_capabilities;
};
#define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO)
--
2.34.1
