[PATCH 1/3] vfio-iommufd: Support pasid [at|de]tach for physical VFIO devices

Yi Liu
2023-11-27T06:39:12Z

From: Kevin Tian <kevin.tian@intel.com>

This adds pasid_at|de]tach_ioas ops for attaching hwpt to pasid of a
device and the helpers for it. For now, only vfio-pci supports pasid
attach/detach.

Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
drivers/vfio/iommufd.c | 48 +++++++++++++++++++++++++++++++++++++
drivers/vfio/pci/vfio_pci.c | 2 ++
include/linux/vfio.h | 11 +++++++++
3 files changed, 61 insertions(+)

diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 82eba6966fa5..43a702b9b4d3 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -119,6 +119,7 @@ int vfio_iommufd_physical_bind(struct vfio_device *vdev,
if (IS_ERR(idev))
return PTR_ERR(idev);
vdev->iommufd_device = idev;
+ xa_init(&vdev->pasid_pts);
return 0;
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_bind);
@@ -127,6 +128,17 @@ void vfio_iommufd_physical_unbind(struct vfio_device *vdev)
{
lockdep_assert_held(&vdev->dev_set->lock);

+ if (!xa_empty(&vdev->pasid_pts)) {
+ void *entry;
+ unsigned long index;
+
+ xa_for_each(&vdev->pasid_pts, index, entry) {
+ xa_erase(&vdev->pasid_pts, index);
+ iommufd_device_pasid_detach(vdev->iommufd_device, index);
+ }
+ xa_destroy(&vdev->pasid_pts);
+ }
+
if (vdev->iommufd_attached) {
iommufd_device_detach(vdev->iommufd_device);
vdev->iommufd_attached = false;
@@ -168,6 +180,42 @@ void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev)
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_detach_ioas);

+int vfio_iommufd_physical_pasid_attach_ioas(struct vfio_device *vdev,
+ u32 pasid, u32 *pt_id)
+{
+ void *entry;
+ int rc;
+
+ lockdep_assert_held(&vdev->dev_set->lock);
+
+ if (WARN_ON(!vdev->iommufd_device))
+ return -EINVAL;
+
+ entry = xa_load(&vdev->pasid_pts, pasid);
+ if (xa_is_value(entry))
+ rc = iommufd_device_pasid_replace(vdev->iommufd_device, pasid, pt_id);
+ else
+ rc = iommufd_device_pasid_attach(vdev->iommufd_device, pasid, pt_id);
+ if (rc)
+ return rc;
+ xa_store(&vdev->pasid_pts, pasid, xa_mk_value(*pt_id), GFP_KERNEL);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_physical_pasid_attach_ioas);
+
+void vfio_iommufd_physical_pasid_detach_ioas(struct vfio_device *vdev, u32 pasid)
+{
+ lockdep_assert_held(&vdev->dev_set->lock);
+
+ if (WARN_ON(!vdev->iommufd_device) ||
+ !xa_is_value(xa_load(&vdev->pasid_pts, pasid)))
+ return;
+
+ iommufd_device_pasid_detach(vdev->iommufd_device, pasid);
+ xa_erase(&vdev->pasid_pts, pasid);
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_physical_pasid_detach_ioas);
+
/*
* The emulated standard ops mean that vfio_device is going to use the
* "mdev path" and will call vfio_pin_pages()/vfio_dma_rw(). Drivers using this
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index cb5b7f865d58..e0198851ffd2 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -142,6 +142,8 @@ static const struct vfio_device_ops vfio_pci_ops = {
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
.detach_ioas = vfio_iommufd_physical_detach_ioas,
+ .pasid_attach_ioas = vfio_iommufd_physical_pasid_attach_ioas,
+ .pasid_detach_ioas = vfio_iommufd_physical_pasid_detach_ioas,
};

static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 454e9295970c..7b06d1bc7cb3 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -66,6 +66,7 @@ struct vfio_device {
void (*put_kvm)(struct kvm *kvm);
#if IS_ENABLED(CONFIG_IOMMUFD)
struct iommufd_device *iommufd_device;
+ struct xarray pasid_pts;
u8 iommufd_attached:1;
#endif
u8 cdev_opened:1;
@@ -83,6 +84,8 @@ struct vfio_device {
* bound iommufd. Undo in unbind_iommufd if @detach_ioas is not
* called.
* @detach_ioas: Opposite of attach_ioas
+ * @pasid_attach_ioas: The pasid variation of attach_ioas
+ * @pasid_detach_ioas: Opposite of pasid_attach_ioas
* @open_device: Called when the first file descriptor is opened for this device
* @close_device: Opposite of open_device
* @read: Perform read(2) on device file descriptor
@@ -107,6 +110,8 @@ struct vfio_device_ops {
void (*unbind_iommufd)(struct vfio_device *vdev);
int (*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
void (*detach_ioas)(struct vfio_device *vdev);
+ int (*pasid_attach_ioas)(struct vfio_device *vdev, u32 pasid, u32 *pt_id);
+ void (*pasid_detach_ioas)(struct vfio_device *vdev, u32 pasid);
int (*open_device)(struct vfio_device *vdev);
void (*close_device)(struct vfio_device *vdev);
ssize_t (*read)(struct vfio_device *vdev, char __user *buf,
@@ -131,6 +136,8 @@ int vfio_iommufd_physical_bind(struct vfio_device *vdev,
void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev);
+int vfio_iommufd_physical_pasid_attach_ioas(struct vfio_device *vdev, u32 pasid, u32 *pt_id);
+void vfio_iommufd_physical_pasid_detach_ioas(struct vfio_device *vdev, u32 pasid);
int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
struct iommufd_ctx *ictx, u32 *out_device_id);
void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
@@ -158,6 +165,10 @@ vfio_iommufd_get_dev_id(struct vfio_device *vdev, struct iommufd_ctx *ictx)
((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
#define vfio_iommufd_physical_detach_ioas \
((void (*)(struct vfio_device *vdev)) NULL)
+#define vfio_iommufd_physical_pasid_attach_ioas \
+ ((int (*)(struct vfio_device *vdev, u32 pasid, u32 *pt_id)) NULL)
+#define vfio_iommufd_physical_pasid_detach_ioas \
+ ((void (*)(struct vfio_device *vdev, u32 pasid)) NULL)
#define vfio_iommufd_emulated_bind \
((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx, \
u32 *out_device_id)) NULL)
--
2.34.1