On 2019/10/15 下午6:41, Cornelia Huck wrote:
On Fri, 11 Oct 2019 16:15:54 +0800
Jason Wang <jasowang@xxxxxxxxxx> wrote:
Currently, except for the create and remove, the rest of
mdev_parent_ops is designed for vfio-mdev driver only and may not help
for kernel mdev driver. With the help of class id, this patch
introduces device specific callbacks inside mdev_device
structure. This allows different set of callback to be used by
vfio-mdev and virtio-mdev.
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
.../driver-api/vfio-mediated-device.rst | 22 +++++---
MAINTAINERS | 1 +
drivers/gpu/drm/i915/gvt/kvmgt.c | 18 ++++---
drivers/s390/cio/vfio_ccw_ops.c | 18 ++++---
drivers/s390/crypto/vfio_ap_ops.c | 14 +++--
drivers/vfio/mdev/mdev_core.c | 9 +++-
drivers/vfio/mdev/mdev_private.h | 1 +
drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
include/linux/mdev.h | 42 +++------------
include/linux/vfio_mdev.h | 52 +++++++++++++++++++
samples/vfio-mdev/mbochs.c | 20 ++++---
samples/vfio-mdev/mdpy.c | 21 +++++---
samples/vfio-mdev/mtty.c | 18 ++++---
13 files changed, 177 insertions(+), 96 deletions(-)
create mode 100644 include/linux/vfio_mdev.h
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 2035e48da7b2..553574ebba73 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -152,11 +152,20 @@ callbacks per mdev parent device, per mdev type, or any other categorization.
Vendor drivers are expected to be fully asynchronous in this respect or
provide their own internal resource protection.)
-The callbacks in the mdev_parent_ops structure are as follows:
+In order to support multiple types of device/driver, device needs to
+provide both class_id and device_ops through:
"As multiple types of mediated devices may be supported, the device
needs to set up the class id and the device specific callbacks via:"
?
-* open: open callback of mediated device
-* close: close callback of mediated device
-* ioctl: ioctl callback of mediated device
+ void mdev_set_class(struct mdev_device *mdev, u16 id, const void *ops);
+
+The class_id is used to be paired with ids in id_table in mdev_driver
+structure for probing the correct driver.
"The class id (specified in id) is used to match a device with an mdev
driver via its id table."
?
The device_ops is device
+specific callbacks which can be get through mdev_get_dev_ops()
+function by mdev bus driver.
"The device specific callbacks (specified in *ops) are obtainable via
mdev_get_dev_ops() (for use by the mdev bus driver.)"
?
For vfio-mdev device, its device specific
+ops are as follows:
"A vfio-mdev device (class id MDEV_ID_VFIO) uses the following
device-specific ops:"
?
All you propose is better than what I wrote, will change the docs.
+
+* open: open callback of vfio mediated device
+* close: close callback of vfio mediated device
+* ioctl: ioctl callback of vfio mediated device
* read : read emulation callback
* write: write emulation callback
* mmap: mmap emulation callback
@@ -167,9 +176,10 @@ register itself with the mdev core driver::
extern int mdev_register_device(struct device *dev,
const struct mdev_parent_ops *ops);
-It is also required to specify the class_id through::
+It is also required to specify the class_id and device specific ops through::
- extern int mdev_set_class(struct device *dev, u16 id);
+ extern int mdev_set_class(struct device *dev, u16 id,
+ const void *ops);
Apologies if that has already been discussed, but do we want a 1:1
relationship between id and ops, or can different devices with the same
id register different ops?
I think we have a N:1 mapping between id and ops, e.g we want both
virtio-mdev and vhost-mdev use a single set of device ops.
Thanks
If the former, would it make sense to first
register the ops for an id (once), and then have the ->create callback
only set the class id (with the core doing the lookup of the ops)?
However, the mdev_parent_ops structure is not required in the function call
that a driver should use to unregister itself with the mdev core driver::
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