[PATCH v12 01/13] vfio: VFIO_IOMMU_SET_PASID_TABLE

Eric Auger
2021-02-23T21:08:19Z

From: "Liu, Yi L" <yi.l.liu@linux.intel.com>

This patch adds an VFIO_IOMMU_SET_PASID_TABLE ioctl
which aims to pass the virtual iommu guest configuration
to the host. This latter takes the form of the so-called
PASID table.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v11 -> v12:
- use iommu_uapi_set_pasid_table
- Rework the flags checks [Zenghui, Alex]
- use VFIO_BASE + 19 [Alex]
- rework the unwind in vfio_attach_pasid_table() [Alex]

v8 -> v9:
- Merge VFIO_IOMMU_ATTACH/DETACH_PASID_TABLE into a single
VFIO_IOMMU_SET_PASID_TABLE ioctl.

v6 -> v7:
- add a comment related to VFIO_IOMMU_DETACH_PASID_TABLE

v3 -> v4:
- restore ATTACH/DETACH
- add unwind on failure

v2 -> v3:
- s/BIND_PASID_TABLE/SET_PASID_TABLE

v1 -> v2:
- s/BIND_GUEST_STAGE/BIND_PASID_TABLE
- remove the struct device arg
---
drivers/vfio/vfio_iommu_type1.c | 58 +++++++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 19 +++++++++++
2 files changed, 77 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0b4dedaa9128..50c4f8ae5b03 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2587,6 +2587,39 @@ static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,
return ret;
}

+static void
+vfio_detach_pasid_table(struct vfio_iommu *iommu)
+{
+ struct vfio_domain *d;
+
+ mutex_lock(&iommu->lock);
+ list_for_each_entry(d, &iommu->domain_list, next)
+ iommu_detach_pasid_table(d->domain);
+
+ mutex_unlock(&iommu->lock);
+}
+
+static int
+vfio_attach_pasid_table(struct vfio_iommu *iommu, unsigned long arg)
+{
+ struct vfio_domain *d;
+ int ret = 0;
+
+ mutex_lock(&iommu->lock);
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ ret = iommu_uapi_attach_pasid_table(d->domain, (void __user *)arg);
+ if (ret) {
+ list_for_each_entry_continue_reverse(d, &iommu->domain_list, next)
+ iommu_detach_pasid_table(d->domain);
+ break;
+ }
+ }
+
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
struct vfio_info_cap *caps)
{
@@ -2747,6 +2780,29 @@ static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
-EFAULT : 0;
}

+static int vfio_iommu_type1_set_pasid_table(struct vfio_iommu *iommu,
+ unsigned long arg)
+{
+ struct vfio_iommu_type1_set_pasid_table spt;
+ unsigned long minsz;
+
+ minsz = offsetofend(struct vfio_iommu_type1_set_pasid_table, flags);
+
+ if (copy_from_user(&spt, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (spt.argsz < minsz)
+ return -EINVAL;
+
+ if (spt.flags == VFIO_PASID_TABLE_FLAG_SET) {
+ return vfio_attach_pasid_table(iommu, arg + minsz);
+ } else if (spt.flags == VFIO_PASID_TABLE_FLAG_UNSET) {
+ vfio_detach_pasid_table(iommu);
+ return 0;
+ }
+ return -EINVAL;
+}
+
static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
unsigned long arg)
{
@@ -2867,6 +2923,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
return vfio_iommu_type1_unmap_dma(iommu, arg);
case VFIO_IOMMU_DIRTY_PAGES:
return vfio_iommu_type1_dirty_pages(iommu, arg);
+ case VFIO_IOMMU_SET_PASID_TABLE:
+ return vfio_iommu_type1_set_pasid_table(iommu, arg);
default:
return -ENOTTY;
}
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index d1812777139f..6d77779c941d 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -14,6 +14,7 @@

#include <linux/types.h>
#include <linux/ioctl.h>
+#include <linux/iommu.h>

#define VFIO_API_VERSION 0

@@ -1181,6 +1182,24 @@ struct vfio_iommu_type1_dirty_bitmap_get {

#define VFIO_IOMMU_DIRTY_PAGES _IO(VFIO_TYPE, VFIO_BASE + 17)

+/*
+ * VFIO_IOMMU_SET_PASID_TABLE - _IOWR(VFIO_TYPE, VFIO_BASE + 18,
+ * struct vfio_iommu_type1_set_pasid_table)
+ *
+ * The SET operation passes a PASID table to the host while the
+ * UNSET operation detaches the one currently programmed. Setting
+ * a table while another is already programmed replaces the old table.
+ */
+struct vfio_iommu_type1_set_pasid_table {
+ __u32 argsz;
+ __u32 flags;
+#define VFIO_PASID_TABLE_FLAG_SET (1 << 0)
+#define VFIO_PASID_TABLE_FLAG_UNSET (1 << 1)
+ struct iommu_pasid_table_config config; /* used on SET */
+};
+
+#define VFIO_IOMMU_SET_PASID_TABLE _IO(VFIO_TYPE, VFIO_BASE + 18)
+
/* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */

/*
--
2.26.2