[PATCH v10 13/22] vfio-iommufd: Add detach_ioas support for physical VFIO devices

Yi Liu
2023-04-26T15:04:53Z

this prepares for adding DETACH ioctl for physical VFIO devices.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
Documentation/driver-api/vfio.rst | 8 +++++---
drivers/vfio/fsl-mc/vfio_fsl_mc.c | 1 +
drivers/vfio/iommufd.c | 20 +++++++++++++++++++
.../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 2 ++
drivers/vfio/pci/mlx5/main.c | 1 +
drivers/vfio/pci/vfio_pci.c | 1 +
drivers/vfio/platform/vfio_amba.c | 1 +
drivers/vfio/platform/vfio_platform.c | 1 +
drivers/vfio/vfio_main.c | 3 ++-
include/linux/vfio.h | 8 +++++++-
10 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/Documentation/driver-api/vfio.rst b/Documentation/driver-api/vfio.rst
index 68abc089d6dd..363e12c90b87 100644
--- a/Documentation/driver-api/vfio.rst
+++ b/Documentation/driver-api/vfio.rst
@@ -279,6 +279,7 @@ similar to a file operations structure::
struct iommufd_ctx *ictx, u32 *out_device_id);
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 (*open_device)(struct vfio_device *vdev);
void (*close_device)(struct vfio_device *vdev);
ssize_t (*read)(struct vfio_device *vdev, char __user *buf,
@@ -315,9 +316,10 @@ container_of().
- The [un]bind_iommufd callbacks are issued when the device is bound to
and unbound from iommufd.

- - The attach_ioas callback is issued when the device is attached to an
- IOAS managed by the bound iommufd. The attached IOAS is automatically
- detached when the device is unbound from iommufd.
+ - The [de]attach_ioas callback is issued when the device is attached to
+ and detached from an IOAS managed by the bound iommufd. However, the
+ attached IOAS can also be automatically detached when the device is
+ unbound from iommufd.

- The read/write/mmap callbacks implement the device region access defined
by the device's own VFIO_DEVICE_GET_REGION_INFO ioctl.
diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
index c89a047a4cd8..d540cf683d93 100644
--- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c
+++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c
@@ -594,6 +594,7 @@ static const struct vfio_device_ops vfio_fsl_mc_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static struct fsl_mc_driver vfio_fsl_mc_driver = {
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index ce7ea27d049a..fad040998c30 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -135,6 +135,14 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
{
int rc;

+ lockdep_assert_held(&vdev->dev_set->lock);
+
+ if (WARN_ON(!vdev->iommufd_device))
+ return -EINVAL;
+
+ if (vdev->iommufd_attached)
+ return -EBUSY;
+
rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
if (rc)
return rc;
@@ -143,6 +151,18 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
}
EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);

+void vfio_iommufd_physical_detach_ioas(struct vfio_device *vdev)
+{
+ lockdep_assert_held(&vdev->dev_set->lock);
+
+ if (WARN_ON(!vdev->iommufd_device) || !vdev->iommufd_attached)
+ return;
+
+ iommufd_device_detach(vdev->iommufd_device);
+ vdev->iommufd_attached = false;
+}
+EXPORT_SYMBOL_GPL(vfio_iommufd_physical_detach_ioas);
+
/*
* The emulated standard ops can be used by below usages:
* 1) The vfio_device that is going to use the "mdev path" and will call
diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
index a117eaf21c14..b2f9778c8366 100644
--- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
+++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c
@@ -1373,6 +1373,7 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_migrn_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
@@ -1391,6 +1392,7 @@ static const struct vfio_device_ops hisi_acc_vfio_pci_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static int hisi_acc_vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
diff --git a/drivers/vfio/pci/mlx5/main.c b/drivers/vfio/pci/mlx5/main.c
index d95fd382814c..42ec574a8622 100644
--- a/drivers/vfio/pci/mlx5/main.c
+++ b/drivers/vfio/pci/mlx5/main.c
@@ -1320,6 +1320,7 @@ static const struct vfio_device_ops mlx5vf_pci_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static int mlx5vf_pci_probe(struct pci_dev *pdev,
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 29091ee2e984..cb5b7f865d58 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -141,6 +141,7 @@ static const struct vfio_device_ops vfio_pci_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
diff --git a/drivers/vfio/platform/vfio_amba.c b/drivers/vfio/platform/vfio_amba.c
index 83fe54015595..6464b3939ebc 100644
--- a/drivers/vfio/platform/vfio_amba.c
+++ b/drivers/vfio/platform/vfio_amba.c
@@ -119,6 +119,7 @@ static const struct vfio_device_ops vfio_amba_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static const struct amba_id pl330_ids[] = {
diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c
index 22a1efca32a8..8cf22fa65baa 100644
--- a/drivers/vfio/platform/vfio_platform.c
+++ b/drivers/vfio/platform/vfio_platform.c
@@ -108,6 +108,7 @@ static const struct vfio_device_ops vfio_platform_ops = {
.bind_iommufd = vfio_iommufd_physical_bind,
.unbind_iommufd = vfio_iommufd_physical_unbind,
.attach_ioas = vfio_iommufd_physical_attach_ioas,
+ .detach_ioas = vfio_iommufd_physical_detach_ioas,
};

static struct platform_driver vfio_platform_driver = {
diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index d3e8f480be2c..0f1139126622 100644
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -258,7 +258,8 @@ static int __vfio_register_dev(struct vfio_device *device,
if (WARN_ON(IS_ENABLED(CONFIG_IOMMUFD) &&
(!device->ops->bind_iommufd ||
!device->ops->unbind_iommufd ||
- !device->ops->attach_ioas)))
+ !device->ops->attach_ioas ||
+ !device->ops->detach_ioas)))
return -EINVAL;

/*
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 3de2923b6e22..9e16e195d1b7 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -75,7 +75,9 @@ struct vfio_device {
* @bind_iommufd: Called when binding the device to an iommufd
* @unbind_iommufd: Opposite of bind_iommufd
* @attach_ioas: Called when attaching device to an IOAS/HWPT managed by the
- * bound iommufd. Undo in unbind_iommufd.
+ * bound iommufd. Undo in unbind_iommufd if @detach_ioas is not
+ * called.
+ * @detach_ioas: Opposite of 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
@@ -99,6 +101,7 @@ struct vfio_device_ops {
struct iommufd_ctx *ictx, u32 *out_device_id);
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 (*open_device)(struct vfio_device *vdev);
void (*close_device)(struct vfio_device *vdev);
ssize_t (*read)(struct vfio_device *vdev, char __user *buf,
@@ -122,6 +125,7 @@ int vfio_iommufd_physical_bind(struct vfio_device *vdev,
struct iommufd_ctx *ictx, u32 *out_device_id);
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_emulated_bind(struct vfio_device *vdev,
struct iommufd_ctx *ictx, u32 *out_device_id);
void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
@@ -146,6 +150,8 @@ vfio_iommufd_physical_devid(struct vfio_device *vdev)
((void (*)(struct vfio_device *vdev)) NULL)
#define vfio_iommufd_physical_attach_ioas \
((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
+#define vfio_iommufd_physical_detach_ioas \
+ ((void (*)(struct vfio_device *vdev)) NULL)
#define vfio_iommufd_emulated_bind \
((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx, \
u32 *out_device_id)) NULL)
--
2.34.1