[PATCH v9 01/11] vfio: VFIO_IOMMU_SET_PASID_TABLE

From: Eric Auger
Date: Thu Jul 11 2019 - 09:56:44 EST


From: "Liu, Yi L" <yi.l.liu@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx>
Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx>
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>

---
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 | 56 +++++++++++++++++++++++++++++++++
include/uapi/linux/vfio.h | 19 +++++++++++
2 files changed, 75 insertions(+)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index add34adfadc7..757a859f96a3 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -1755,6 +1755,43 @@ static int vfio_domains_have_iommu_cache(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,
+ struct vfio_iommu_type1_set_pasid_table *ustruct)
+{
+ struct vfio_domain *d;
+ int ret = 0;
+
+ mutex_lock(&iommu->lock);
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ ret = iommu_attach_pasid_table(d->domain, &ustruct->config);
+ if (ret)
+ goto unwind;
+ }
+ goto unlock;
+unwind:
+ list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
+ iommu_detach_pasid_table(d->domain);
+ }
+unlock:
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
@@ -1825,6 +1862,25 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,

return copy_to_user((void __user *)arg, &unmap, minsz) ?
-EFAULT : 0;
+ } else if (cmd == VFIO_IOMMU_SET_PASID_TABLE) {
+ struct vfio_iommu_type1_set_pasid_table ustruct;
+
+ minsz = offsetofend(struct vfio_iommu_type1_set_pasid_table,
+ config);
+
+ if (copy_from_user(&ustruct, (void __user *)arg, minsz))
+ return -EFAULT;
+
+ if (ustruct.argsz < minsz)
+ return -EINVAL;
+
+ if (ustruct.flags & VFIO_PASID_TABLE_FLAG_SET)
+ return vfio_attach_pasid_table(iommu, &ustruct);
+ else if (ustruct.flags & VFIO_PASID_TABLE_FLAG_UNSET) {
+ vfio_detach_pasid_table(iommu);
+ return 0;
+ } else
+ return -EINVAL;
}

return -ENOTTY;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 8f10748dac79..96039da0a52d 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

@@ -763,6 +764,24 @@ struct vfio_iommu_type1_dma_unmap {
#define VFIO_IOMMU_ENABLE _IO(VFIO_TYPE, VFIO_BASE + 15)
#define VFIO_IOMMU_DISABLE _IO(VFIO_TYPE, VFIO_BASE + 16)

+/**
+ * VFIO_IOMMU_SET_PASID_TABLE - _IOWR(VFIO_TYPE, VFIO_BASE + 22,
+ * 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 + 22)
+
/* -------- Additional API for SPAPR TCE (Server POWERPC) IOMMU -------- */

/*
--
2.20.1