* [PATCH V4 0/6] mdev based hardware virtio offloading support
@ 2019-10-17 10:48 Jason Wang
2019-10-17 10:48 ` [PATCH V4 1/6] mdev: class id support Jason Wang
` (5 more replies)
0 siblings, 6 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
Hi all:
There are hardwares that can do virtio datapath offloading while
having its own control path. This path tries to implement a mdev based
unified API to support using kernel virtio driver to drive those
devices. This is done by introducing a new mdev transport for virtio
(virtio_mdev) and register itself as a new kind of mdev driver. Then
it provides a unified way for kernel virtio driver to talk with mdev
device implementation.
Though the series only contains kernel driver support, the goal is to
make the transport generic enough to support userspace drivers. This
means vhost-mdev[1] could be built on top as well by resuing the
transport.
A sample driver is also implemented which simulate a virito-net
loopback ethernet device on top of vringh + workqueue. This could be
used as a reference implementation for real hardware driver.
Also a real ICF VF driver was also posted here[2] which is a good
reference for vendors who is interested in their own virtio datapath
offloading product.
Consider mdev framework only support VFIO device and driver right now,
this series also extend it to support other types. This is done
through introducing class id to the device and pairing it with
id_talbe claimed by the driver. On top, this seris also decouple
device specific parents ops out of the common ones.
Pktgen test was done with virito-net + mvnet loop back device.
Please review.
[1] https://lkml.org/lkml/2019/9/26/15
[2] https://lkml.org/lkml/2019/10/15/1226
Changes from V3:
- document that class id (device ops) must be specified in create()
- add WARN() when trying to set class_id when it has already set
- add WARN() when class_id is not specified in create() and correctly
return an error in this case
- correct the prototype of mdev_set_class() in the doc
- add documention of mdev_set_class()
- remove the unnecessary "class_id_fail" label when class id is not
specified in create()
- convert id_table in vfio_mdev to const
- move mdev_set_class and its friends after mdev_uuid()
- suqash the patch of bus uevent into patch of introducing class id
- tweak the words in the docs per Cornelia suggestion
- tie class_id and device ops through class specific initialization
routine like mdev_set_vfio_ops()
- typos fixes in the docs of virtio-mdev callbacks
- document the usage of virtqueues in struct virtio_mdev_device
- remove the useless vqs array in struct virtio_mdev_device
- rename MDEV_ID_XXX to MDEV_CLASS_ID_XXX
Changes from V2:
- fail when class_id is not specified
- drop the vringh patch
- match the doc to the code
- tweak the commit log
- move device_ops from parent to mdev device
- remove the unused MDEV_ID_VHOST
Changes from V1:
- move virtio_mdev.c to drivers/virtio
- store class_id in mdev_device instead of mdev_parent
- store device_ops in mdev_device instead of mdev_parent
- reorder the patch, vringh fix comes first
- really silent compiling warnings
- really switch to use u16 for class_id
- uevent and modpost support for mdev class_id
- vraious tweaks per comments from Parav
Changes from RFC-V2:
- silent compile warnings on some specific configuration
- use u16 instead u8 for class id
- reseve MDEV_ID_VHOST for future vhost-mdev work
- introduce "virtio" type for mvnet and make "vhost" type for future
work
- add entries in MAINTAINER
- tweak and typos fixes in commit log
Changes from RFC-V1:
- rename device id to class id
- add docs for class id and device specific ops (device_ops)
- split device_ops into seperate headers
- drop the mdev_set_dma_ops()
- use device_ops to implement the transport API, then it's not a part
of UAPI any more
- use GFP_ATOMIC in mvnet sample device and other tweaks
- set_vring_base/get_vring_base support for mvnet device
Jason Wang (6):
mdev: class id support
modpost: add support for mdev class id
mdev: introduce device specific ops
mdev: introduce virtio device and its device ops
virtio: introduce a mdev based transport
docs: sample driver to demonstrate how to implement virtio-mdev
framework
.../driver-api/vfio-mediated-device.rst | 22 +-
MAINTAINERS | 2 +
drivers/gpu/drm/i915/gvt/kvmgt.c | 17 +-
drivers/s390/cio/vfio_ccw_ops.c | 17 +-
drivers/s390/crypto/vfio_ap_ops.c | 13 +-
drivers/vfio/mdev/mdev_core.c | 38 +
drivers/vfio/mdev/mdev_driver.c | 22 +
drivers/vfio/mdev/mdev_private.h | 2 +
drivers/vfio/mdev/vfio_mdev.c | 45 +-
drivers/virtio/Kconfig | 7 +
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_mdev.c | 409 +++++++++++
include/linux/mdev.h | 55 +-
include/linux/mod_devicetable.h | 8 +
include/linux/vfio_mdev.h | 52 ++
include/linux/virtio_mdev.h | 151 ++++
samples/Kconfig | 7 +
samples/vfio-mdev/Makefile | 1 +
samples/vfio-mdev/mbochs.c | 19 +-
samples/vfio-mdev/mdpy.c | 19 +-
samples/vfio-mdev/mtty.c | 17 +-
samples/vfio-mdev/mvnet.c | 691 ++++++++++++++++++
scripts/mod/devicetable-offsets.c | 3 +
scripts/mod/file2alias.c | 10 +
24 files changed, 1541 insertions(+), 87 deletions(-)
create mode 100644 drivers/virtio/virtio_mdev.c
create mode 100644 include/linux/vfio_mdev.h
create mode 100644 include/linux/virtio_mdev.h
create mode 100644 samples/vfio-mdev/mvnet.c
--
2.19.1
^ permalink raw reply [flat|nested] 27+ messages in thread
* [PATCH V4 1/6] mdev: class id support
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
@ 2019-10-17 10:48 ` Jason Wang
2019-10-20 23:25 ` Parav Pandit
2019-10-17 10:48 ` [PATCH V4 2/6] modpost: add support for mdev class id Jason Wang
` (4 subsequent siblings)
5 siblings, 1 reply; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
Mdev bus only supports vfio driver right now, so it doesn't implement
match method. But in the future, we may add drivers other than vfio,
the first driver could be virtio-mdev. This means we need to add
device class id support in bus match method to pair the mdev device
and mdev driver correctly.
So this patch adds id_table to mdev_driver and class_id for mdev
device with the match method for mdev bus.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
.../driver-api/vfio-mediated-device.rst | 7 +++++-
drivers/gpu/drm/i915/gvt/kvmgt.c | 1 +
drivers/s390/cio/vfio_ccw_ops.c | 1 +
drivers/s390/crypto/vfio_ap_ops.c | 1 +
drivers/vfio/mdev/mdev_core.c | 18 +++++++++++++++
drivers/vfio/mdev/mdev_driver.c | 22 +++++++++++++++++++
drivers/vfio/mdev/mdev_private.h | 1 +
drivers/vfio/mdev/vfio_mdev.c | 6 +++++
include/linux/mdev.h | 8 +++++++
include/linux/mod_devicetable.h | 8 +++++++
samples/vfio-mdev/mbochs.c | 1 +
samples/vfio-mdev/mdpy.c | 1 +
samples/vfio-mdev/mtty.c | 1 +
13 files changed, 75 insertions(+), 1 deletion(-)
diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst
index 25eb7d5b834b..f9a78d75a67a 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -102,12 +102,14 @@ structure to represent a mediated device's driver::
* @probe: called when new device created
* @remove: called when device removed
* @driver: device driver structure
+ * @id_table: the ids serviced by this driver
*/
struct mdev_driver {
const char *name;
int (*probe) (struct device *dev);
void (*remove) (struct device *dev);
struct device_driver driver;
+ const struct mdev_class_id *id_table;
};
A mediated bus driver for mdev should use this structure in the function calls
@@ -165,12 +167,15 @@ 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 in create() callback through::
+
+ int mdev_set_class(struct mdev_device *mdev, u16 id);
+
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::
extern void mdev_unregister_device(struct device *dev);
-
Mediated Device Management Interface Through sysfs
==================================================
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 343d79c1cb7e..6420f0dbd31b 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -678,6 +678,7 @@ static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
dev_name(mdev_dev(mdev)));
ret = 0;
+ mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
out:
return ret;
}
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index f0d71ab77c50..cf2c013ae32f 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -129,6 +129,7 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
private->sch->schid.ssid,
private->sch->schid.sch_no);
+ mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
return 0;
}
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 5c0f53c6dde7..07c31070afeb 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -343,6 +343,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
mutex_unlock(&matrix_dev->lock);
+ mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
return 0;
}
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index b558d4cfd082..3a9c52d71b4e 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -45,6 +45,16 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data)
}
EXPORT_SYMBOL(mdev_set_drvdata);
+/* Specify the class for the mdev device, this must be called during
+ * create() callback.
+ */
+void mdev_set_class(struct mdev_device *mdev, u16 id)
+{
+ WARN_ON(mdev->class_id);
+ mdev->class_id = id;
+}
+EXPORT_SYMBOL(mdev_set_class);
+
struct device *mdev_dev(struct mdev_device *mdev)
{
return &mdev->dev;
@@ -135,6 +145,7 @@ static int mdev_device_remove_cb(struct device *dev, void *data)
* mdev_register_device : Register a device
* @dev: device structure representing parent device.
* @ops: Parent device operation structure to be registered.
+ * @id: class id.
*
* Add device to list of registered parent devices.
* Returns a negative value on error, otherwise 0.
@@ -324,6 +335,13 @@ int mdev_device_create(struct kobject *kobj,
if (ret)
goto ops_create_fail;
+ if (!mdev->class_id) {
+ ret = -EINVAL;
+ WARN(1, "class id must be specified for device %s\n",
+ dev_name(dev));
+ goto add_fail;
+ }
+
ret = device_add(&mdev->dev);
if (ret)
goto add_fail;
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 0d3223aee20b..319d886ffaf7 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -69,8 +69,30 @@ static int mdev_remove(struct device *dev)
return 0;
}
+static int mdev_match(struct device *dev, struct device_driver *drv)
+{
+ unsigned int i;
+ struct mdev_device *mdev = to_mdev_device(dev);
+ struct mdev_driver *mdrv = to_mdev_driver(drv);
+ const struct mdev_class_id *ids = mdrv->id_table;
+
+ for (i = 0; ids[i].id; i++)
+ if (ids[i].id == mdev->class_id)
+ return 1;
+ return 0;
+}
+
+static int mdev_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ return add_uevent_var(env, "MODALIAS=mdev:c%02X", mdev->class_id);
+}
+
struct bus_type mdev_bus_type = {
.name = "mdev",
+ .match = mdev_match,
+ .uevent = mdev_uevent,
.probe = mdev_probe,
.remove = mdev_remove,
};
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index 7d922950caaf..c65f436c1869 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -33,6 +33,7 @@ struct mdev_device {
struct kobject *type_kobj;
struct device *iommu_device;
bool active;
+ u16 class_id;
};
#define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index 30964a4e0a28..7b24ee9cb8dd 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -120,10 +120,16 @@ static void vfio_mdev_remove(struct device *dev)
vfio_del_group_dev(dev);
}
+static const struct mdev_class_id id_table[] = {
+ { MDEV_CLASS_ID_VFIO },
+ { 0 },
+};
+
static struct mdev_driver vfio_mdev_driver = {
.name = "vfio_mdev",
.probe = vfio_mdev_probe,
.remove = vfio_mdev_remove,
+ .id_table = id_table,
};
static int __init vfio_mdev_init(void)
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 0ce30ca78db0..78b69d09eb54 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -118,6 +118,7 @@ struct mdev_type_attribute mdev_type_attr_##_name = \
* @probe: called when new device created
* @remove: called when device removed
* @driver: device driver structure
+ * @id_table: the ids serviced by this driver
*
**/
struct mdev_driver {
@@ -125,6 +126,7 @@ struct mdev_driver {
int (*probe)(struct device *dev);
void (*remove)(struct device *dev);
struct device_driver driver;
+ const struct mdev_class_id *id_table;
};
#define to_mdev_driver(drv) container_of(drv, struct mdev_driver, driver)
@@ -132,6 +134,7 @@ struct mdev_driver {
void *mdev_get_drvdata(struct mdev_device *mdev);
void mdev_set_drvdata(struct mdev_device *mdev, void *data);
const guid_t *mdev_uuid(struct mdev_device *mdev);
+void mdev_set_class(struct mdev_device *mdev, u16 id);
extern struct bus_type mdev_bus_type;
@@ -145,4 +148,9 @@ struct device *mdev_parent_dev(struct mdev_device *mdev);
struct device *mdev_dev(struct mdev_device *mdev);
struct mdev_device *mdev_from_dev(struct device *dev);
+enum {
+ MDEV_CLASS_ID_VFIO = 1,
+ /* New entries must be added here */
+};
+
#endif /* MDEV_H */
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 5714fd35a83c..f32c6e44fb1a 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -821,4 +821,12 @@ struct wmi_device_id {
const void *context;
};
+/**
+ * struct mdev_class_id - MDEV device class identifier
+ * @id: Used to identify a specific class of device, e.g vfio-mdev device.
+ */
+struct mdev_class_id {
+ __u16 id;
+};
+
#endif /* LINUX_MOD_DEVICETABLE_H */
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index ac5c8c17b1ff..115bc5074656 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -561,6 +561,7 @@ static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)
mbochs_reset(mdev);
mbochs_used_mbytes += type->mbytes;
+ mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
return 0;
err_mem:
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index cc86bf6566e4..665614574d50 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -269,6 +269,7 @@ static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)
mdpy_reset(mdev);
mdpy_count++;
+ mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
return 0;
}
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index ce84a300a4da..90da12ff7fd9 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -755,6 +755,7 @@ static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
list_add(&mdev_state->next, &mdev_devices_list);
mutex_unlock(&mdev_list_lock);
+ mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
return 0;
}
--
2.19.1
^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH V4 2/6] modpost: add support for mdev class id
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
2019-10-17 10:48 ` [PATCH V4 1/6] mdev: class id support Jason Wang
@ 2019-10-17 10:48 ` Jason Wang
2019-10-20 23:25 ` Parav Pandit
2019-10-17 10:48 ` [PATCH V4 3/6] mdev: introduce device specific ops Jason Wang
` (3 subsequent siblings)
5 siblings, 1 reply; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
Add support to parse mdev class id table.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vfio/mdev/vfio_mdev.c | 2 ++
scripts/mod/devicetable-offsets.c | 3 +++
scripts/mod/file2alias.c | 10 ++++++++++
3 files changed, 15 insertions(+)
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index 7b24ee9cb8dd..cb701cd646f0 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -125,6 +125,8 @@ static const struct mdev_class_id id_table[] = {
{ 0 },
};
+MODULE_DEVICE_TABLE(mdev, id_table);
+
static struct mdev_driver vfio_mdev_driver = {
.name = "vfio_mdev",
.probe = vfio_mdev_probe,
diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
index 054405b90ba4..6cbb1062488a 100644
--- a/scripts/mod/devicetable-offsets.c
+++ b/scripts/mod/devicetable-offsets.c
@@ -231,5 +231,8 @@ int main(void)
DEVID(wmi_device_id);
DEVID_FIELD(wmi_device_id, guid_string);
+ DEVID(mdev_class_id);
+ DEVID_FIELD(mdev_class_id, id);
+
return 0;
}
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index c91eba751804..d365dfe7c718 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -1335,6 +1335,15 @@ static int do_wmi_entry(const char *filename, void *symval, char *alias)
return 1;
}
+/* looks like: "mdev:cN" */
+static int do_mdev_entry(const char *filename, void *symval, char *alias)
+{
+ DEF_FIELD(symval, mdev_class_id, id);
+
+ sprintf(alias, "mdev:c%02X", id);
+ return 1;
+}
+
/* Does namelen bytes of name exactly match the symbol? */
static bool sym_is(const char *name, unsigned namelen, const char *symbol)
{
@@ -1407,6 +1416,7 @@ static const struct devtable devtable[] = {
{"typec", SIZE_typec_device_id, do_typec_entry},
{"tee", SIZE_tee_client_device_id, do_tee_entry},
{"wmi", SIZE_wmi_device_id, do_wmi_entry},
+ {"mdev", SIZE_mdev_class_id, do_mdev_entry},
};
/* Create MODULE_ALIAS() statements.
--
2.19.1
^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
2019-10-17 10:48 ` [PATCH V4 1/6] mdev: class id support Jason Wang
2019-10-17 10:48 ` [PATCH V4 2/6] modpost: add support for mdev class id Jason Wang
@ 2019-10-17 10:48 ` Jason Wang
2019-10-17 15:07 ` Cornelia Huck
2019-10-20 23:41 ` Parav Pandit
2019-10-17 10:48 ` [PATCH V4 4/6] mdev: introduce virtio device and its device ops Jason Wang
` (2 subsequent siblings)
5 siblings, 2 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
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@redhat.com>
---
.../driver-api/vfio-mediated-device.rst | 25 +++++----
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 | 18 +++++--
drivers/vfio/mdev/mdev_private.h | 1 +
drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
include/linux/mdev.h | 45 ++++------------
include/linux/vfio_mdev.h | 52 +++++++++++++++++++
samples/vfio-mdev/mbochs.c | 20 ++++---
samples/vfio-mdev/mdpy.c | 20 ++++---
samples/vfio-mdev/mtty.c | 18 ++++---
13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -152,11 +152,22 @@ 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:
-
-* open: open callback of mediated device
-* close: close callback of mediated device
-* ioctl: ioctl callback of mediated device
+As multiple types of mediated devices may be supported, the device
+must set up the class id and the device specific callbacks in create()
+callback. E.g for vfio-mdev device it needs to be done through:
+
+ int mdev_set_vfio_ops(struct mdev_device *mdev,
+ const struct vfio_mdev_ops *vfio_ops);
+
+The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device
+with an mdev driver via its id table. The device specific callbacks
+(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
+the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
+uses the following device-specific ops:
+
+* 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
@@ -167,10 +178,6 @@ 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 in create() callback through::
-
- int mdev_set_class(struct mdev_device *mdev, u16 id);
-
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::
diff --git a/MAINTAINERS b/MAINTAINERS
index 8824f61cd2c0..3d196a023b5e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17127,6 +17127,7 @@ S: Maintained
F: Documentation/driver-api/vfio-mediated-device.rst
F: drivers/vfio/mdev/
F: include/linux/mdev.h
+F: include/linux/vfio_mdev.h
F: samples/vfio-mdev/
VFIO PLATFORM DRIVER
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 6420f0dbd31b..306f934c7857 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -42,6 +42,7 @@
#include <linux/kvm_host.h>
#include <linux/vfio.h>
#include <linux/mdev.h>
+#include <linux/vfio_mdev.h>
#include <linux/debugfs.h>
#include <linux/nospec.h>
@@ -643,6 +644,8 @@ static void kvmgt_put_vfio_device(void *vgpu)
vfio_device_put(((struct intel_vgpu *)vgpu)->vdev.vfio_device);
}
+static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops;
+
static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct intel_vgpu *vgpu = NULL;
@@ -678,7 +681,7 @@ static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
dev_name(mdev_dev(mdev)));
ret = 0;
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(mdev, &intel_vfio_vgpu_dev_ops);
out:
return ret;
}
@@ -1599,20 +1602,21 @@ static const struct attribute_group *intel_vgpu_groups[] = {
NULL,
};
-static struct mdev_parent_ops intel_vgpu_ops = {
- .mdev_attr_groups = intel_vgpu_groups,
- .create = intel_vgpu_create,
- .remove = intel_vgpu_remove,
-
+static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops = {
.open = intel_vgpu_open,
.release = intel_vgpu_release,
-
.read = intel_vgpu_read,
.write = intel_vgpu_write,
.mmap = intel_vgpu_mmap,
.ioctl = intel_vgpu_ioctl,
};
+static struct mdev_parent_ops intel_vgpu_ops = {
+ .mdev_attr_groups = intel_vgpu_groups,
+ .create = intel_vgpu_create,
+ .remove = intel_vgpu_remove,
+};
+
static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
{
struct attribute **kvm_type_attrs;
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index cf2c013ae32f..6e606cdb1aa9 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -12,6 +12,7 @@
#include <linux/vfio.h>
#include <linux/mdev.h>
+#include <linux/vfio_mdev.h>
#include <linux/nospec.h>
#include <linux/slab.h>
@@ -110,6 +111,8 @@ static struct attribute_group *mdev_type_groups[] = {
NULL,
};
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
@@ -129,7 +132,7 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
private->sch->schid.ssid,
private->sch->schid.sch_no);
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
return 0;
}
@@ -575,11 +578,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
}
}
-static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
- .owner = THIS_MODULE,
- .supported_type_groups = mdev_type_groups,
- .create = vfio_ccw_mdev_create,
- .remove = vfio_ccw_mdev_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops = {
.open = vfio_ccw_mdev_open,
.release = vfio_ccw_mdev_release,
.read = vfio_ccw_mdev_read,
@@ -587,6 +586,13 @@ static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
.ioctl = vfio_ccw_mdev_ioctl,
};
+static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
+ .owner = THIS_MODULE,
+ .supported_type_groups = mdev_type_groups,
+ .create = vfio_ccw_mdev_create,
+ .remove = vfio_ccw_mdev_remove,
+};
+
int vfio_ccw_mdev_reg(struct subchannel *sch)
{
return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 07c31070afeb..195c8f4c6f10 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -16,6 +16,7 @@
#include <linux/bitops.h>
#include <linux/kvm_host.h>
#include <linux/module.h>
+#include <linux/vfio_mdev.h>
#include <asm/kvm.h>
#include <asm/zcrypt.h>
@@ -321,6 +322,8 @@ static void vfio_ap_matrix_init(struct ap_config_info *info,
matrix->adm_max = info->apxa ? info->Nd : 15;
}
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct ap_matrix_mdev *matrix_mdev;
@@ -343,7 +346,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
mutex_unlock(&matrix_dev->lock);
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
return 0;
}
@@ -1281,15 +1284,18 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,
return ret;
}
+static const struct vfio_mdev_device_ops vfio_mdev_ops = {
+ .open = vfio_ap_mdev_open,
+ .release = vfio_ap_mdev_release,
+ .ioctl = vfio_ap_mdev_ioctl,
+};
+
static const struct mdev_parent_ops vfio_ap_matrix_ops = {
.owner = THIS_MODULE,
.supported_type_groups = vfio_ap_mdev_type_groups,
.mdev_attr_groups = vfio_ap_mdev_attr_groups,
.create = vfio_ap_mdev_create,
.remove = vfio_ap_mdev_remove,
- .open = vfio_ap_mdev_open,
- .release = vfio_ap_mdev_release,
- .ioctl = vfio_ap_mdev_ioctl,
};
int vfio_ap_mdev_register(void)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 3a9c52d71b4e..d0f3113c8071 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data)
}
EXPORT_SYMBOL(mdev_set_drvdata);
-/* Specify the class for the mdev device, this must be called during
- * create() callback.
+/* Specify the VFIO device ops for the mdev device, this
+ * must be called during create() callback for VFIO mdev device.
*/
-void mdev_set_class(struct mdev_device *mdev, u16 id)
+void mdev_set_vfio_ops(struct mdev_device *mdev,
+ const struct vfio_mdev_device_ops *vfio_ops)
{
WARN_ON(mdev->class_id);
- mdev->class_id = id;
+ mdev->class_id = MDEV_CLASS_ID_VFIO;
+ mdev->device_ops = vfio_ops;
}
-EXPORT_SYMBOL(mdev_set_class);
+EXPORT_SYMBOL(mdev_set_vfio_ops);
+
+const void *mdev_get_dev_ops(struct mdev_device *mdev)
+{
+ return mdev->device_ops;
+}
+EXPORT_SYMBOL(mdev_get_dev_ops);
struct device *mdev_dev(struct mdev_device *mdev)
{
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index c65f436c1869..b666805f0b1f 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -34,6 +34,7 @@ struct mdev_device {
struct device *iommu_device;
bool active;
u16 class_id;
+ const void *device_ops;
};
#define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index cb701cd646f0..6b6b92011436 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -14,6 +14,7 @@
#include <linux/slab.h>
#include <linux/vfio.h>
#include <linux/mdev.h>
+#include <linux/vfio_mdev.h>
#include "mdev_private.h"
@@ -24,16 +25,16 @@
static int vfio_mdev_open(void *device_data)
{
struct mdev_device *mdev = device_data;
- struct mdev_parent *parent = mdev->parent;
+ const struct vfio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
int ret;
- if (unlikely(!parent->ops->open))
+ if (unlikely(!ops->open))
return -EINVAL;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
- ret = parent->ops->open(mdev);
+ ret = ops->open(mdev);
if (ret)
module_put(THIS_MODULE);
@@ -43,10 +44,10 @@ static int vfio_mdev_open(void *device_data)
static void vfio_mdev_release(void *device_data)
{
struct mdev_device *mdev = device_data;
- struct mdev_parent *parent = mdev->parent;
+ const struct vfio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
- if (likely(parent->ops->release))
- parent->ops->release(mdev);
+ if (likely(ops->release))
+ ops->release(mdev);
module_put(THIS_MODULE);
}
@@ -55,47 +56,47 @@ static long vfio_mdev_unlocked_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
struct mdev_device *mdev = device_data;
- struct mdev_parent *parent = mdev->parent;
+ const struct vfio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
- if (unlikely(!parent->ops->ioctl))
+ if (unlikely(!ops->ioctl))
return -EINVAL;
- return parent->ops->ioctl(mdev, cmd, arg);
+ return ops->ioctl(mdev, cmd, arg);
}
static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
size_t count, loff_t *ppos)
{
struct mdev_device *mdev = device_data;
- struct mdev_parent *parent = mdev->parent;
+ const struct vfio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
- if (unlikely(!parent->ops->read))
+ if (unlikely(!ops->read))
return -EINVAL;
- return parent->ops->read(mdev, buf, count, ppos);
+ return ops->read(mdev, buf, count, ppos);
}
static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
size_t count, loff_t *ppos)
{
struct mdev_device *mdev = device_data;
- struct mdev_parent *parent = mdev->parent;
+ const struct vfio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
- if (unlikely(!parent->ops->write))
+ if (unlikely(!ops->write))
return -EINVAL;
- return parent->ops->write(mdev, buf, count, ppos);
+ return ops->write(mdev, buf, count, ppos);
}
static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
{
struct mdev_device *mdev = device_data;
- struct mdev_parent *parent = mdev->parent;
+ const struct vfio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
- if (unlikely(!parent->ops->mmap))
+ if (unlikely(!ops->mmap))
return -EINVAL;
- return parent->ops->mmap(mdev, vma);
+ return ops->mmap(mdev, vma);
}
static const struct vfio_device_ops vfio_mdev_dev_ops = {
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 78b69d09eb54..3d29e09e20c9 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -10,7 +10,13 @@
#ifndef MDEV_H
#define MDEV_H
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/mdev.h>
+#include <uapi/linux/uuid.h>
+
struct mdev_device;
+struct vfio_mdev_device_ops;
/*
* Called by the parent device driver to set the device which represents
@@ -48,30 +54,7 @@ struct device *mdev_get_iommu_device(struct device *dev);
* @mdev: mdev_device device structure which is being
* destroyed
* Returns integer: success (0) or error (< 0)
- * @open: Open mediated device.
- * @mdev: mediated device.
- * Returns integer: success (0) or error (< 0)
- * @release: release mediated device
- * @mdev: mediated device.
- * @read: Read emulation callback
- * @mdev: mediated device structure
- * @buf: read buffer
- * @count: number of bytes to read
- * @ppos: address.
- * Retuns number on bytes read on success or error.
- * @write: Write emulation callback
- * @mdev: mediated device structure
- * @buf: write buffer
- * @count: number of bytes to be written
- * @ppos: address.
- * Retuns number on bytes written on success or error.
- * @ioctl: IOCTL callback
- * @mdev: mediated device structure
- * @cmd: ioctl command
- * @arg: arguments to ioctl
- * @mmap: mmap callback
- * @mdev: mediated device structure
- * @vma: vma structure
+ *
* Parent device that support mediated device should be registered with mdev
* module with mdev_parent_ops structure.
**/
@@ -83,15 +66,6 @@ struct mdev_parent_ops {
int (*create)(struct kobject *kobj, struct mdev_device *mdev);
int (*remove)(struct mdev_device *mdev);
- int (*open)(struct mdev_device *mdev);
- void (*release)(struct mdev_device *mdev);
- ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
- size_t count, loff_t *ppos);
- ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
- size_t count, loff_t *ppos);
- long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
- unsigned long arg);
- int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
};
/* interface for exporting mdev supported type attributes */
@@ -133,8 +107,11 @@ struct mdev_driver {
void *mdev_get_drvdata(struct mdev_device *mdev);
void mdev_set_drvdata(struct mdev_device *mdev, void *data);
+
const guid_t *mdev_uuid(struct mdev_device *mdev);
-void mdev_set_class(struct mdev_device *mdev, u16 id);
+void mdev_set_vfio_ops(struct mdev_device *mdev,
+ const struct vfio_mdev_device_ops *vfio_ops);
+const void *mdev_get_dev_ops(struct mdev_device *mdev);
extern struct bus_type mdev_bus_type;
diff --git a/include/linux/vfio_mdev.h b/include/linux/vfio_mdev.h
new file mode 100644
index 000000000000..3907c5371c2b
--- /dev/null
+++ b/include/linux/vfio_mdev.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * VFIO Mediated device definition
+ */
+
+#ifndef VFIO_MDEV_H
+#define VFIO_MDEV_H
+
+#include <linux/mdev.h>
+
+/**
+ * struct vfio_mdev_device_ops - Structure to be registered for each
+ * mdev device to register the device to vfio-mdev module.
+ *
+ * @open: Open mediated device.
+ * @mdev: mediated device.
+ * Returns integer: success (0) or error (< 0)
+ * @release: release mediated device
+ * @mdev: mediated device.
+ * @read: Read emulation callback
+ * @mdev: mediated device structure
+ * @buf: read buffer
+ * @count: number of bytes to read
+ * @ppos: address.
+ * Retuns number on bytes read on success or error.
+ * @write: Write emulation callback
+ * @mdev: mediated device structure
+ * @buf: write buffer
+ * @count: number of bytes to be written
+ * @ppos: address.
+ * Retuns number on bytes written on success or error.
+ * @ioctl: IOCTL callback
+ * @mdev: mediated device structure
+ * @cmd: ioctl command
+ * @arg: arguments to ioctl
+ * @mmap: mmap callback
+ * @mdev: mediated device structure
+ * @vma: vma structure
+ */
+struct vfio_mdev_device_ops {
+ int (*open)(struct mdev_device *mdev);
+ void (*release)(struct mdev_device *mdev);
+ ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
+ size_t count, loff_t *ppos);
+ ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
+ size_t count, loff_t *ppos);
+ long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
+ unsigned long arg);
+ int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
+};
+
+#endif
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 115bc5074656..37abdf1b27a8 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -30,6 +30,7 @@
#include <linux/iommu.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>
+#include <linux/vfio_mdev.h>
#include <linux/pci.h>
#include <linux/dma-buf.h>
#include <linux/highmem.h>
@@ -516,6 +517,8 @@ static int mbochs_reset(struct mdev_device *mdev)
return 0;
}
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)
{
const struct mbochs_type *type = mbochs_find_type(kobj);
@@ -561,7 +564,7 @@ static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)
mbochs_reset(mdev);
mbochs_used_mbytes += type->mbytes;
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
return 0;
err_mem:
@@ -1419,12 +1422,7 @@ static struct attribute_group *mdev_type_groups[] = {
NULL,
};
-static const struct mdev_parent_ops mdev_fops = {
- .owner = THIS_MODULE,
- .mdev_attr_groups = mdev_dev_groups,
- .supported_type_groups = mdev_type_groups,
- .create = mbochs_create,
- .remove = mbochs_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops = {
.open = mbochs_open,
.release = mbochs_close,
.read = mbochs_read,
@@ -1433,6 +1431,14 @@ static const struct mdev_parent_ops mdev_fops = {
.mmap = mbochs_mmap,
};
+static const struct mdev_parent_ops mdev_fops = {
+ .owner = THIS_MODULE,
+ .mdev_attr_groups = mdev_dev_groups,
+ .supported_type_groups = mdev_type_groups,
+ .create = mbochs_create,
+ .remove = mbochs_remove,
+};
+
static const struct file_operations vd_fops = {
.owner = THIS_MODULE,
};
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 665614574d50..f21c795c40e4 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -26,6 +26,7 @@
#include <linux/iommu.h>
#include <linux/sysfs.h>
#include <linux/mdev.h>
+#include <linux/vfio_mdev.h>
#include <linux/pci.h>
#include <drm/drm_fourcc.h>
#include "mdpy-defs.h"
@@ -226,6 +227,8 @@ static int mdpy_reset(struct mdev_device *mdev)
return 0;
}
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)
{
const struct mdpy_type *type = mdpy_find_type(kobj);
@@ -269,7 +272,7 @@ static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)
mdpy_reset(mdev);
mdpy_count++;
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
return 0;
}
@@ -726,12 +729,7 @@ static struct attribute_group *mdev_type_groups[] = {
NULL,
};
-static const struct mdev_parent_ops mdev_fops = {
- .owner = THIS_MODULE,
- .mdev_attr_groups = mdev_dev_groups,
- .supported_type_groups = mdev_type_groups,
- .create = mdpy_create,
- .remove = mdpy_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops = {
.open = mdpy_open,
.release = mdpy_close,
.read = mdpy_read,
@@ -740,6 +738,14 @@ static const struct mdev_parent_ops mdev_fops = {
.mmap = mdpy_mmap,
};
+static const struct mdev_parent_ops mdev_fops = {
+ .owner = THIS_MODULE,
+ .mdev_attr_groups = mdev_dev_groups,
+ .supported_type_groups = mdev_type_groups,
+ .create = mdpy_create,
+ .remove = mdpy_remove,
+};
+
static const struct file_operations vd_fops = {
.owner = THIS_MODULE,
};
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 90da12ff7fd9..b829f33b98f5 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -27,6 +27,7 @@
#include <linux/ctype.h>
#include <linux/file.h>
#include <linux/mdev.h>
+#include <linux/vfio_mdev.h>
#include <linux/pci.h>
#include <linux/serial.h>
#include <uapi/linux/serial_reg.h>
@@ -708,6 +709,8 @@ static ssize_t mdev_access(struct mdev_device *mdev, u8 *buf, size_t count,
return ret;
}
+static const struct vfio_mdev_device_ops vfio_dev_ops;
+
static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct mdev_state *mdev_state;
@@ -755,7 +758,7 @@ static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
list_add(&mdev_state->next, &mdev_devices_list);
mutex_unlock(&mdev_list_lock);
- mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+ mdev_set_vfio_ops(mdev, &vfio_dev_ops);
return 0;
}
@@ -1388,6 +1391,14 @@ static struct attribute_group *mdev_type_groups[] = {
NULL,
};
+static const struct vfio_mdev_device_ops vfio_dev_ops = {
+ .open = mtty_open,
+ .release = mtty_close,
+ .read = mtty_read,
+ .write = mtty_write,
+ .ioctl = mtty_ioctl,
+};
+
static const struct mdev_parent_ops mdev_fops = {
.owner = THIS_MODULE,
.dev_attr_groups = mtty_dev_groups,
@@ -1395,11 +1406,6 @@ static const struct mdev_parent_ops mdev_fops = {
.supported_type_groups = mdev_type_groups,
.create = mtty_create,
.remove = mtty_remove,
- .open = mtty_open,
- .release = mtty_close,
- .read = mtty_read,
- .write = mtty_write,
- .ioctl = mtty_ioctl,
};
static void mtty_device_release(struct device *dev)
--
2.19.1
^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
` (2 preceding siblings ...)
2019-10-17 10:48 ` [PATCH V4 3/6] mdev: introduce device specific ops Jason Wang
@ 2019-10-17 10:48 ` Jason Wang
2019-10-17 17:53 ` Alex Williamson
` (2 more replies)
2019-10-17 10:48 ` [PATCH V4 5/6] virtio: introduce a mdev based transport Jason Wang
2019-10-17 10:48 ` [PATCH V4 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework Jason Wang
5 siblings, 3 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
This patch implements basic support for mdev driver that supports
virtio transport for kernel virtio driver.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vfio/mdev/mdev_core.c | 12 +++
include/linux/mdev.h | 4 +
include/linux/virtio_mdev.h | 151 ++++++++++++++++++++++++++++++++++
3 files changed, 167 insertions(+)
create mode 100644 include/linux/virtio_mdev.h
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index d0f3113c8071..5834f6b7c7a5 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -57,6 +57,18 @@ void mdev_set_vfio_ops(struct mdev_device *mdev,
}
EXPORT_SYMBOL(mdev_set_vfio_ops);
+/* Specify the virtio device ops for the mdev device, this
+ * must be called during create() callback for virtio mdev device.
+ */
+void mdev_set_virtio_ops(struct mdev_device *mdev,
+ const struct virtio_mdev_device_ops *virtio_ops)
+{
+ BUG_ON(mdev->class_id);
+ mdev->class_id = MDEV_CLASS_ID_VIRTIO;
+ mdev->device_ops = virtio_ops;
+}
+EXPORT_SYMBOL(mdev_set_virtio_ops);
+
const void *mdev_get_dev_ops(struct mdev_device *mdev)
{
return mdev->device_ops;
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 3d29e09e20c9..13e045e09d3b 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -17,6 +17,7 @@
struct mdev_device;
struct vfio_mdev_device_ops;
+struct virtio_mdev_device_ops;
/*
* Called by the parent device driver to set the device which represents
@@ -111,6 +112,8 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data);
const guid_t *mdev_uuid(struct mdev_device *mdev);
void mdev_set_vfio_ops(struct mdev_device *mdev,
const struct vfio_mdev_device_ops *vfio_ops);
+void mdev_set_virtio_ops(struct mdev_device *mdev,
+ const struct virtio_mdev_device_ops *virtio_ops);
const void *mdev_get_dev_ops(struct mdev_device *mdev);
extern struct bus_type mdev_bus_type;
@@ -127,6 +130,7 @@ struct mdev_device *mdev_from_dev(struct device *dev);
enum {
MDEV_CLASS_ID_VFIO = 1,
+ MDEV_CLASS_ID_VIRTIO = 2,
/* New entries must be added here */
};
diff --git a/include/linux/virtio_mdev.h b/include/linux/virtio_mdev.h
new file mode 100644
index 000000000000..b965b50f9b24
--- /dev/null
+++ b/include/linux/virtio_mdev.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Virtio mediated device driver
+ *
+ * Copyright 2019, Red Hat Corp.
+ * Author: Jason Wang <jasowang@redhat.com>
+ */
+#ifndef _LINUX_VIRTIO_MDEV_H
+#define _LINUX_VIRTIO_MDEV_H
+
+#include <linux/interrupt.h>
+#include <linux/mdev.h>
+#include <uapi/linux/vhost.h>
+
+#define VIRTIO_MDEV_DEVICE_API_STRING "virtio-mdev"
+#define VIRTIO_MDEV_F_VERSION_1 0x1
+
+struct virtio_mdev_callback {
+ irqreturn_t (*callback)(void *data);
+ void *private;
+};
+
+/**
+ * struct vfio_mdev_device_ops - Structure to be registered for each
+ * mdev device to register the device to virtio-mdev module.
+ *
+ * @set_vq_address: Set the address of virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * @desc_area: address of desc area
+ * @driver_area: address of driver area
+ * @device_area: address of device area
+ * Returns integer: success (0) or error (< 0)
+ * @set_vq_num: Set the size of virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * @num: the size of virtqueue
+ * @kick_vq: Kick the virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * @set_vq_cb: Set the interrupt callback function for
+ * a virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * @cb: virtio-mdev interrupt callback structure
+ * @set_vq_ready: Set ready status for a virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * @ready: ready (true) not ready(false)
+ * @get_vq_ready: Get ready status for a virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * Returns boolean: ready (true) or not (false)
+ * @set_vq_state: Set the state for a virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * @state: virtqueue state (last_avail_idx)
+ * Returns integer: success (0) or error (< 0)
+ * @get_vq_state: Get the state for a virtqueue
+ * @mdev: mediated device
+ * @idx: virtqueue index
+ * Returns virtqueue state (last_avail_idx)
+ * @get_vq_align: Get the virtqueue align requirement
+ * for the device
+ * @mdev: mediated device
+ * Returns virtqueue algin requirement
+ * @get_features: Get virtio features supported by the device
+ * @mdev: mediated device
+ * Returns the virtio features support by the
+ * device
+ * @get_features: Set virtio features supported by the driver
+ * @mdev: mediated device
+ * @features: feature support by the driver
+ * Returns integer: success (0) or error (< 0)
+ * @set_config_cb: Set the config interrupt callback
+ * @mdev: mediated device
+ * @cb: virtio-mdev interrupt callback structure
+ * @get_vq_num_max: Get the max size of virtqueue
+ * @mdev: mediated device
+ * Returns u16: max size of virtqueue
+ * @get_device_id: Get virtio device id
+ * @mdev: mediated device
+ * Returns u32: virtio device id
+ * @get_vendor_id: Get virtio vendor id
+ * @mdev: mediated device
+ * Returns u32: virtio vendor id
+ * @get_status: Get the device status
+ * @mdev: mediated device
+ * Returns u8: virtio device status
+ * @set_status: Set the device status
+ * @mdev: mediated device
+ * @status: virtio device status
+ * @get_config: Read from device specific configuration space
+ * @mdev: mediated device
+ * @offset: offset from the beginning of
+ * configuration space
+ * @buf: buffer used to read to
+ * @len: the length to read from
+ * configration space
+ * @set_config: Write to device specific configuration space
+ * @mdev: mediated device
+ * @offset: offset from the beginning of
+ * configuration space
+ * @buf: buffer used to write from
+ * @len: the length to write to
+ * configration space
+ * @get_mdev_features: Get the feature of virtio mdev device
+ * @mdev: mediated device
+ * Returns the mdev features (API) support by
+ * the device.
+ * @get_generation: Get device generaton
+ * @mdev: mediated device
+ * Returns u32: device generation
+ */
+struct virtio_mdev_device_ops {
+ /* Virtqueue ops */
+ int (*set_vq_address)(struct mdev_device *mdev,
+ u16 idx, u64 desc_area, u64 driver_area,
+ u64 device_area);
+ void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
+ void (*kick_vq)(struct mdev_device *mdev, u16 idx);
+ void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
+ struct virtio_mdev_callback *cb);
+ void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
+ bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
+ int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
+ u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
+
+ /* Device ops */
+ u16 (*get_vq_align)(struct mdev_device *mdev);
+ u64 (*get_features)(struct mdev_device *mdev);
+ int (*set_features)(struct mdev_device *mdev, u64 features);
+ void (*set_config_cb)(struct mdev_device *mdev,
+ struct virtio_mdev_callback *cb);
+ u16 (*get_vq_num_max)(struct mdev_device *mdev);
+ u32 (*get_device_id)(struct mdev_device *mdev);
+ u32 (*get_vendor_id)(struct mdev_device *mdev);
+ u8 (*get_status)(struct mdev_device *mdev);
+ void (*set_status)(struct mdev_device *mdev, u8 status);
+ void (*get_config)(struct mdev_device *mdev, unsigned int offset,
+ void *buf, unsigned int len);
+ void (*set_config)(struct mdev_device *mdev, unsigned int offset,
+ const void *buf, unsigned int len);
+ u64 (*get_mdev_features)(struct mdev_device *mdev);
+ u32 (*get_generation)(struct mdev_device *mdev);
+};
+
+void mdev_set_virtio_ops(struct mdev_device *mdev,
+ const struct virtio_mdev_device_ops *virtio_ops);
+
+#endif
--
2.19.1
^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH V4 5/6] virtio: introduce a mdev based transport
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
` (3 preceding siblings ...)
2019-10-17 10:48 ` [PATCH V4 4/6] mdev: introduce virtio device and its device ops Jason Wang
@ 2019-10-17 10:48 ` Jason Wang
2019-10-18 14:20 ` Cornelia Huck
2019-10-17 10:48 ` [PATCH V4 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework Jason Wang
5 siblings, 1 reply; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
This patch introduces a new mdev transport for virtio. This is used to
use kernel virtio driver to drive the mediated device that is capable
of populating virtqueue directly.
A new virtio-mdev driver will be registered to the mdev bus, when a
new virtio-mdev device is probed, it will register the device with
mdev based config ops. This means it is a software transport between
mdev driver and mdev device. The transport was implemented through
device specific ops which is a part of mdev_parent_ops now.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/virtio/Kconfig | 7 +
drivers/virtio/Makefile | 1 +
drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++
3 files changed, 417 insertions(+)
create mode 100644 drivers/virtio/virtio_mdev.c
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 078615cf2afc..8d18722ab572 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -43,6 +43,13 @@ config VIRTIO_PCI_LEGACY
If unsure, say Y.
+config VIRTIO_MDEV_DEVICE
+ tristate "VIRTIO driver for Mediated devices"
+ depends on VFIO_MDEV && VIRTIO
+ default n
+ help
+ VIRTIO based driver for Mediated devices.
+
config VIRTIO_PMEM
tristate "Support for virtio pmem driver"
depends on VIRTIO
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
index 3a2b5c5dcf46..ebc7fa15ae82 100644
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -6,3 +6,4 @@ virtio_pci-y := virtio_pci_modern.o virtio_pci_common.o
virtio_pci-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o
+obj-$(CONFIG_VIRTIO_MDEV_DEVICE) += virtio_mdev.o
diff --git a/drivers/virtio/virtio_mdev.c b/drivers/virtio/virtio_mdev.c
new file mode 100644
index 000000000000..24c0df5ffe77
--- /dev/null
+++ b/drivers/virtio/virtio_mdev.c
@@ -0,0 +1,409 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * VIRTIO based driver for Mediated device
+ *
+ * Copyright (c) 2019, Red Hat. All rights reserved.
+ * Author: Jason Wang <jasowang@redhat.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/uuid.h>
+#include <linux/mdev.h>
+#include <linux/virtio_mdev.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+
+#define DRIVER_VERSION "0.1"
+#define DRIVER_AUTHOR "Red Hat Corporation"
+#define DRIVER_DESC "VIRTIO based driver for Mediated device"
+
+#define to_virtio_mdev_device(dev) \
+ container_of(dev, struct virtio_mdev_device, vdev)
+
+struct virtio_mdev_device {
+ struct virtio_device vdev;
+ struct mdev_device *mdev;
+ unsigned long version;
+
+ /* The lock to protect virtqueue list */
+ spinlock_t lock;
+ /* List of virtio_mdev_vq_info */
+ struct list_head virtqueues;
+};
+
+struct virtio_mdev_vq_info {
+ /* the actual virtqueue */
+ struct virtqueue *vq;
+
+ /* the list node for the virtqueues list */
+ struct list_head node;
+};
+
+static struct mdev_device *vm_get_mdev(struct virtio_device *vdev)
+{
+ struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev);
+ struct mdev_device *mdev = vm_dev->mdev;
+
+ return mdev;
+}
+
+static void virtio_mdev_get(struct virtio_device *vdev, unsigned offset,
+ void *buf, unsigned len)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ ops->get_config(mdev, offset, buf, len);
+}
+
+static void virtio_mdev_set(struct virtio_device *vdev, unsigned offset,
+ const void *buf, unsigned len)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ ops->set_config(mdev, offset, buf, len);
+}
+
+static u32 virtio_mdev_generation(struct virtio_device *vdev)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ return ops->get_generation(mdev);
+}
+
+static u8 virtio_mdev_get_status(struct virtio_device *vdev)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ return ops->get_status(mdev);
+}
+
+static void virtio_mdev_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ return ops->set_status(mdev, status);
+}
+
+static void virtio_mdev_reset(struct virtio_device *vdev)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ return ops->set_status(mdev, 0);
+}
+
+static bool virtio_mdev_notify(struct virtqueue *vq)
+{
+ struct mdev_device *mdev = vm_get_mdev(vq->vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ ops->kick_vq(mdev, vq->index);
+
+ return true;
+}
+
+static irqreturn_t virtio_mdev_config_cb(void *private)
+{
+ struct virtio_mdev_device *vm_dev = private;
+
+ virtio_config_changed(&vm_dev->vdev);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t virtio_mdev_virtqueue_cb(void *private)
+{
+ struct virtio_mdev_vq_info *info = private;
+
+ return vring_interrupt(0, info->vq);
+}
+
+static struct virtqueue *
+virtio_mdev_setup_vq(struct virtio_device *vdev, unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name, bool ctx)
+{
+ struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev);
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+ struct virtio_mdev_vq_info *info;
+ struct virtio_mdev_callback cb;
+ struct virtqueue *vq;
+ u64 desc_addr, driver_addr, device_addr;
+ unsigned long flags;
+ u32 align, num;
+ int err;
+
+ if (!name)
+ return NULL;
+
+ /* Queue shouldn't already be set up. */
+ if (ops->get_vq_ready(mdev, index))
+ return ERR_PTR(-ENOENT);
+
+ /* Allocate and fill out our active queue description */
+ info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ num = ops->get_vq_num_max(mdev);
+ if (num == 0) {
+ err = -ENOENT;
+ goto error_new_virtqueue;
+ }
+
+ /* Create the vring */
+ align = ops->get_vq_align(mdev);
+ vq = vring_create_virtqueue(index, num, align, vdev,
+ true, true, ctx,
+ virtio_mdev_notify, callback, name);
+ if (!vq) {
+ err = -ENOMEM;
+ goto error_new_virtqueue;
+ }
+
+ /* Setup virtqueue callback */
+ cb.callback = virtio_mdev_virtqueue_cb;
+ cb.private = info;
+ ops->set_vq_cb(mdev, index, &cb);
+ ops->set_vq_num(mdev, index, virtqueue_get_vring_size(vq));
+
+ desc_addr = virtqueue_get_desc_addr(vq);
+ driver_addr = virtqueue_get_avail_addr(vq);
+ device_addr = virtqueue_get_used_addr(vq);
+
+ if (ops->set_vq_address(mdev, index,
+ desc_addr, driver_addr,
+ device_addr)) {
+ err = -EINVAL;
+ goto err_vq;
+ }
+
+ ops->set_vq_ready(mdev, index, 1);
+
+ vq->priv = info;
+ info->vq = vq;
+
+ spin_lock_irqsave(&vm_dev->lock, flags);
+ list_add(&info->node, &vm_dev->virtqueues);
+ spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+ return vq;
+
+err_vq:
+ vring_del_virtqueue(vq);
+error_new_virtqueue:
+ ops->set_vq_ready(mdev, index, 0);
+ WARN_ON(ops->get_vq_ready(mdev, index));
+ kfree(info);
+ return ERR_PTR(err);
+
+}
+
+static void virtio_mdev_del_vq(struct virtqueue *vq)
+{
+ struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vq->vdev);
+ struct mdev_device *mdev = vm_dev->mdev;
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+ struct virtio_mdev_vq_info *info = vq->priv;
+ unsigned int index = vq->index;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vm_dev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vm_dev->lock, flags);
+
+ /* Select and deactivate the queue */
+ ops->set_vq_ready(mdev, index, 0);
+ WARN_ON(ops->get_vq_ready(mdev, index));
+
+ vring_del_virtqueue(vq);
+
+ kfree(info);
+}
+
+static void virtio_mdev_del_vqs(struct virtio_device *vdev)
+{
+ struct virtqueue *vq, *n;
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+ virtio_mdev_del_vq(vq);
+}
+
+static int virtio_mdev_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char * const names[],
+ const bool *ctx,
+ struct irq_affinity *desc)
+{
+ struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev);
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+ struct virtio_mdev_callback cb;
+ int i, err, queue_idx = 0;
+
+ for (i = 0; i < nvqs; ++i) {
+ if (!names[i]) {
+ vqs[i] = NULL;
+ continue;
+ }
+
+ vqs[i] = virtio_mdev_setup_vq(vdev, queue_idx++,
+ callbacks[i], names[i], ctx ?
+ ctx[i] : false);
+ if (IS_ERR(vqs[i])) {
+ err = PTR_ERR(vqs[i]);
+ goto err_setup_vq;
+ }
+ }
+
+ cb.callback = virtio_mdev_config_cb;
+ cb.private = vm_dev;
+ ops->set_config_cb(mdev, &cb);
+
+ return 0;
+
+err_setup_vq:
+ virtio_mdev_del_vqs(vdev);
+ return err;
+}
+
+static u64 virtio_mdev_get_features(struct virtio_device *vdev)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ return ops->get_features(mdev);
+}
+
+static int virtio_mdev_finalize_features(struct virtio_device *vdev)
+{
+ struct mdev_device *mdev = vm_get_mdev(vdev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ return ops->set_features(mdev, vdev->features);
+}
+
+static const char *virtio_mdev_bus_name(struct virtio_device *vdev)
+{
+ struct virtio_mdev_device *vm_dev = to_virtio_mdev_device(vdev);
+ struct mdev_device *mdev = vm_dev->mdev;
+
+ return dev_name(mdev_dev(mdev));
+}
+
+static const struct virtio_config_ops virtio_mdev_config_ops = {
+ .get = virtio_mdev_get,
+ .set = virtio_mdev_set,
+ .generation = virtio_mdev_generation,
+ .get_status = virtio_mdev_get_status,
+ .set_status = virtio_mdev_set_status,
+ .reset = virtio_mdev_reset,
+ .find_vqs = virtio_mdev_find_vqs,
+ .del_vqs = virtio_mdev_del_vqs,
+ .get_features = virtio_mdev_get_features,
+ .finalize_features = virtio_mdev_finalize_features,
+ .bus_name = virtio_mdev_bus_name,
+};
+
+static void virtio_mdev_release_dev(struct device *_d)
+{
+ struct virtio_device *vdev =
+ container_of(_d, struct virtio_device, dev);
+ struct virtio_mdev_device *vm_dev =
+ container_of(vdev, struct virtio_mdev_device, vdev);
+
+ devm_kfree(_d, vm_dev);
+}
+
+static int virtio_mdev_probe(struct device *dev)
+{
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
+ struct virtio_mdev_device *vm_dev;
+ int rc;
+
+ vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL);
+ if (!vm_dev)
+ return -ENOMEM;
+
+ vm_dev->vdev.dev.parent = dev;
+ vm_dev->vdev.dev.release = virtio_mdev_release_dev;
+ vm_dev->vdev.config = &virtio_mdev_config_ops;
+ vm_dev->mdev = mdev;
+ INIT_LIST_HEAD(&vm_dev->virtqueues);
+ spin_lock_init(&vm_dev->lock);
+
+ vm_dev->version = ops->get_mdev_features(mdev);
+ if (vm_dev->version != VIRTIO_MDEV_F_VERSION_1) {
+ dev_err(dev, "VIRTIO_MDEV_F_VERSION_1 is mandatory\n");
+ return -ENXIO;
+ }
+
+ vm_dev->vdev.id.device = ops->get_device_id(mdev);
+ if (vm_dev->vdev.id.device == 0)
+ return -ENODEV;
+
+ vm_dev->vdev.id.vendor = ops->get_vendor_id(mdev);
+ rc = register_virtio_device(&vm_dev->vdev);
+ if (rc)
+ put_device(dev);
+ else
+ dev_set_drvdata(dev, vm_dev);
+
+ return rc;
+}
+
+static void virtio_mdev_remove(struct device *dev)
+{
+ struct virtio_mdev_device *vm_dev = dev_get_drvdata(dev);
+
+ unregister_virtio_device(&vm_dev->vdev);
+}
+
+static const struct mdev_class_id id_table[] = {
+ { MDEV_CLASS_ID_VIRTIO },
+ { 0 },
+};
+
+MODULE_DEVICE_TABLE(mdev, id_table);
+
+static struct mdev_driver virtio_mdev_driver = {
+ .name = "virtio_mdev",
+ .probe = virtio_mdev_probe,
+ .remove = virtio_mdev_remove,
+ .id_table = id_table,
+};
+
+static int __init virtio_mdev_init(void)
+{
+ return mdev_register_driver(&virtio_mdev_driver, THIS_MODULE);
+}
+
+static void __exit virtio_mdev_exit(void)
+{
+ mdev_unregister_driver(&virtio_mdev_driver);
+}
+
+module_init(virtio_mdev_init)
+module_exit(virtio_mdev_exit)
+
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
--
2.19.1
^ permalink raw reply related [flat|nested] 27+ messages in thread
* [PATCH V4 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
` (4 preceding siblings ...)
2019-10-17 10:48 ` [PATCH V4 5/6] virtio: introduce a mdev based transport Jason Wang
@ 2019-10-17 10:48 ` Jason Wang
5 siblings, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-17 10:48 UTC (permalink / raw)
To: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha,
Jason Wang
This sample driver creates mdev device that simulate virtio net device
over virtio mdev transport. The device is implemented through vringh
and workqueue. A device specific dma ops is to make sure HVA is used
directly as the IOVA. This should be sufficient for kernel virtio
driver to work.
Only 'virtio' type is supported right now. I plan to add 'vhost' type
on top which requires some virtual IOMMU implemented in this sample
driver.
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
MAINTAINERS | 1 +
samples/Kconfig | 7 +
samples/vfio-mdev/Makefile | 1 +
samples/vfio-mdev/mvnet.c | 691 +++++++++++++++++++++++++++++++++++++
4 files changed, 700 insertions(+)
create mode 100644 samples/vfio-mdev/mvnet.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 3d196a023b5e..cb51351cd5c9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17254,6 +17254,7 @@ F: include/linux/virtio*.h
F: include/uapi/linux/virtio_*.h
F: drivers/crypto/virtio/
F: mm/balloon_compaction.c
+F: samples/vfio-mdev/mvnet.c
VIRTIO BLOCK AND SCSI DRIVERS
M: "Michael S. Tsirkin" <mst@redhat.com>
diff --git a/samples/Kconfig b/samples/Kconfig
index c8dacb4dda80..a1a1ca2c00b7 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -131,6 +131,13 @@ config SAMPLE_VFIO_MDEV_MDPY
mediated device. It is a simple framebuffer and supports
the region display interface (VFIO_GFX_PLANE_TYPE_REGION).
+config SAMPLE_VIRTIO_MDEV_NET
+ tristate "Build virtio mdev net example mediated device sample code -- loadable modules only"
+ depends on VIRTIO_MDEV_DEVICE && VHOST_RING && m
+ help
+ Build a networking sample device for use as a virtio
+ mediated device.
+
config SAMPLE_VFIO_MDEV_MDPY_FB
tristate "Build VFIO mdpy example guest fbdev driver -- loadable module only"
depends on FB && m
diff --git a/samples/vfio-mdev/Makefile b/samples/vfio-mdev/Makefile
index 10d179c4fdeb..f34af90ed0a0 100644
--- a/samples/vfio-mdev/Makefile
+++ b/samples/vfio-mdev/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_SAMPLE_VFIO_MDEV_MTTY) += mtty.o
obj-$(CONFIG_SAMPLE_VFIO_MDEV_MDPY) += mdpy.o
obj-$(CONFIG_SAMPLE_VFIO_MDEV_MDPY_FB) += mdpy-fb.o
obj-$(CONFIG_SAMPLE_VFIO_MDEV_MBOCHS) += mbochs.o
+obj-$(CONFIG_SAMPLE_VIRTIO_MDEV_NET) += mvnet.o
diff --git a/samples/vfio-mdev/mvnet.c b/samples/vfio-mdev/mvnet.c
new file mode 100644
index 000000000000..19e823a449cd
--- /dev/null
+++ b/samples/vfio-mdev/mvnet.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Mediated virtual virtio-net device driver.
+ *
+ * Copyright (c) 2019, Red Hat Inc. All rights reserved.
+ * Author: Jason Wang <jasowang@redhat.com>
+ *
+ * Sample driver that creates mdev device that simulates ethernet loopback
+ * device.
+ *
+ * Usage:
+ *
+ * # modprobe virtio_mdev
+ * # modprobe mvnet
+ * # cd /sys/devices/virtual/mvnet/mvnet/mdev_supported_types/mvnet-virtio
+ * # echo "83b8f4f2-509f-382f-3c1e-e6bfe0fa1001" > ./create
+ * # cd devices/83b8f4f2-509f-382f-3c1e-e6bfe0fa1001
+ * # ls -d virtio0
+ * virtio0
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/uuid.h>
+#include <linux/iommu.h>
+#include <linux/sysfs.h>
+#include <linux/file.h>
+#include <linux/etherdevice.h>
+#include <linux/mdev.h>
+#include <linux/vringh.h>
+#include <linux/virtio_mdev.h>
+#include <uapi/linux/virtio_config.h>
+#include <uapi/linux/virtio_net.h>
+
+#define VERSION_STRING "0.1"
+#define DRIVER_AUTHOR "Red Hat Corporation"
+
+#define MVNET_CLASS_NAME "mvnet"
+#define MVNET_NAME "mvnet"
+
+/*
+ * Global Structures
+ */
+
+static struct mvnet_dev {
+ struct class *vd_class;
+ struct idr vd_idr;
+ struct device dev;
+} mvnet_dev;
+
+struct mvnet_virtqueue {
+ struct vringh vring;
+ struct vringh_kiov iov;
+ unsigned short head;
+ bool ready;
+ u64 desc_addr;
+ u64 device_addr;
+ u64 driver_addr;
+ u32 num;
+ void *private;
+ irqreturn_t (*cb)(void *data);
+};
+
+#define MVNET_QUEUE_ALIGN PAGE_SIZE
+#define MVNET_QUEUE_MAX 256
+#define MVNET_DEVICE_ID 0x1
+#define MVNET_VENDOR_ID 0
+
+u64 mvnet_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
+ (1ULL << VIRTIO_F_VERSION_1) |
+ (1ULL << VIRTIO_F_IOMMU_PLATFORM);
+
+/* State of each mdev device */
+struct mvnet_state {
+ struct mvnet_virtqueue vqs[2];
+ struct work_struct work;
+ spinlock_t lock;
+ struct mdev_device *mdev;
+ struct virtio_net_config config;
+ void *buffer;
+ u32 status;
+ u32 generation;
+ u64 features;
+ struct list_head next;
+};
+
+static struct mutex mdev_list_lock;
+static struct list_head mdev_devices_list;
+
+static void mvnet_queue_ready(struct mvnet_state *mvnet, unsigned int idx)
+{
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+ int ret;
+
+ ret = vringh_init_kern(&vq->vring, mvnet_features, MVNET_QUEUE_MAX,
+ false, (struct vring_desc *)vq->desc_addr,
+ (struct vring_avail *)vq->driver_addr,
+ (struct vring_used *)vq->device_addr);
+}
+
+static void mvnet_vq_reset(struct mvnet_virtqueue *vq)
+{
+ vq->ready = 0;
+ vq->desc_addr = 0;
+ vq->driver_addr = 0;
+ vq->device_addr = 0;
+ vq->cb = NULL;
+ vq->private = NULL;
+ vringh_init_kern(&vq->vring, mvnet_features, MVNET_QUEUE_MAX,
+ false, 0, 0, 0);
+}
+
+static void mvnet_reset(struct mvnet_state *mvnet)
+{
+ int i;
+
+ for (i = 0; i < 2; i++)
+ mvnet_vq_reset(&mvnet->vqs[i]);
+
+ mvnet->features = 0;
+ mvnet->status = 0;
+ ++mvnet->generation;
+}
+
+static void mvnet_work(struct work_struct *work)
+{
+ struct mvnet_state *mvnet = container_of(work, struct
+ mvnet_state, work);
+ struct mvnet_virtqueue *txq = &mvnet->vqs[1];
+ struct mvnet_virtqueue *rxq = &mvnet->vqs[0];
+ size_t read, write, total_write;
+ int err;
+ int pkts = 0;
+
+ spin_lock(&mvnet->lock);
+
+ if (!txq->ready || !rxq->ready)
+ goto out;
+
+ while (true) {
+ total_write = 0;
+ err = vringh_getdesc_kern(&txq->vring, &txq->iov, NULL,
+ &txq->head, GFP_ATOMIC);
+ if (err <= 0)
+ break;
+
+ err = vringh_getdesc_kern(&rxq->vring, NULL, &rxq->iov,
+ &rxq->head, GFP_ATOMIC);
+ if (err <= 0) {
+ vringh_complete_kern(&txq->vring, txq->head, 0);
+ break;
+ }
+
+ while (true) {
+ read = vringh_iov_pull_kern(&txq->iov, mvnet->buffer,
+ PAGE_SIZE);
+ if (read <= 0)
+ break;
+
+ write = vringh_iov_push_kern(&rxq->iov, mvnet->buffer,
+ read);
+ if (write <= 0)
+ break;
+
+ total_write += write;
+ }
+
+ /* Make sure data is wrote before advancing index */
+ smp_wmb();
+
+ vringh_complete_kern(&txq->vring, txq->head, 0);
+ vringh_complete_kern(&rxq->vring, rxq->head, total_write);
+
+ /* Make sure used is visible before rasing the interrupt. */
+ smp_wmb();
+
+ local_bh_disable();
+ if (txq->cb)
+ txq->cb(txq->private);
+ if (rxq->cb)
+ rxq->cb(rxq->private);
+ local_bh_enable();
+
+ if (++pkts > 4) {
+ schedule_work(&mvnet->work);
+ goto out;
+ }
+ }
+
+out:
+ spin_unlock(&mvnet->lock);
+}
+
+static dma_addr_t mvnet_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ /* Vringh can only use HVA */
+ return (dma_addr_t)(page_address(page) + offset);
+}
+
+static void mvnet_unmap_page(struct device *dev, dma_addr_t dma_addr,
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+}
+
+static void *mvnet_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_addr, gfp_t flag,
+ unsigned long attrs)
+{
+ void *addr = kmalloc(size, flag);
+
+ if (addr == NULL)
+ *dma_addr = DMA_MAPPING_ERROR;
+ else
+ *dma_addr = (dma_addr_t) addr;
+
+ return addr;
+}
+
+static void mvnet_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_addr,
+ unsigned long attrs)
+{
+ kfree((void *)dma_addr);
+}
+
+static const struct dma_map_ops mvnet_dma_ops = {
+ .map_page = mvnet_map_page,
+ .unmap_page = mvnet_unmap_page,
+ .alloc = mvnet_alloc_coherent,
+ .free = mvnet_free_coherent,
+};
+
+static const struct virtio_mdev_device_ops virtio_mdev_ops;
+
+static int mvnet_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+ struct mvnet_state *mvnet;
+ struct virtio_net_config *config;
+ struct device *dev = mdev_dev(mdev);
+
+ if (!mdev)
+ return -EINVAL;
+
+ mvnet = kzalloc(sizeof(struct mvnet_state), GFP_KERNEL);
+ if (mvnet == NULL)
+ return -ENOMEM;
+
+ mvnet->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!mvnet->buffer) {
+ kfree(mvnet);
+ return -ENOMEM;
+ }
+
+ config = &mvnet->config;
+ config->mtu = 1500;
+ config->status = VIRTIO_NET_S_LINK_UP;
+ eth_random_addr(config->mac);
+
+ INIT_WORK(&mvnet->work, mvnet_work);
+
+ spin_lock_init(&mvnet->lock);
+ mvnet->mdev = mdev;
+ mdev_set_drvdata(mdev, mvnet);
+
+ mutex_lock(&mdev_list_lock);
+ list_add(&mvnet->next, &mdev_devices_list);
+ mutex_unlock(&mdev_list_lock);
+
+ dev->coherent_dma_mask = DMA_BIT_MASK(64);
+ set_dma_ops(dev, &mvnet_dma_ops);
+
+ mdev_set_virtio_ops(mdev, &virtio_mdev_ops);
+
+ return 0;
+}
+
+static int mvnet_remove(struct mdev_device *mdev)
+{
+ struct mvnet_state *mds, *tmp_mds;
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ int ret = -EINVAL;
+
+ mutex_lock(&mdev_list_lock);
+ list_for_each_entry_safe(mds, tmp_mds, &mdev_devices_list, next) {
+ if (mvnet == mds) {
+ list_del(&mvnet->next);
+ mdev_set_drvdata(mdev, NULL);
+ kfree(mvnet->buffer);
+ kfree(mvnet);
+ ret = 0;
+ break;
+ }
+ }
+ mutex_unlock(&mdev_list_lock);
+
+ return ret;
+}
+
+static ssize_t
+sample_mvnet_dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ if (mdev_from_dev(dev))
+ return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
+
+ return sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR_RO(sample_mvnet_dev);
+
+static struct attribute *mvnet_dev_attrs[] = {
+ &dev_attr_sample_mvnet_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group mvnet_dev_group = {
+ .name = "mvnet_dev",
+ .attrs = mvnet_dev_attrs,
+};
+
+static const struct attribute_group *mvnet_dev_groups[] = {
+ &mvnet_dev_group,
+ NULL,
+};
+
+static ssize_t
+sample_mdev_dev_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ if (mdev_from_dev(dev))
+ return sprintf(buf, "This is MDEV %s\n", dev_name(dev));
+
+ return sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR_RO(sample_mdev_dev);
+
+static struct attribute *mdev_dev_attrs[] = {
+ &dev_attr_sample_mdev_dev.attr,
+ NULL,
+};
+
+static const struct attribute_group mdev_dev_group = {
+ .name = "vendor",
+ .attrs = mdev_dev_attrs,
+};
+
+static const struct attribute_group *mdev_dev_groups[] = {
+ &mdev_dev_group,
+ NULL,
+};
+
+#define MVNET_STRING_LEN 16
+
+static ssize_t
+name_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ char name[MVNET_STRING_LEN];
+ const char *name_str = "virtio-net";
+
+ snprintf(name, MVNET_STRING_LEN, "%s", dev_driver_string(dev));
+ if (!strcmp(kobj->name, name))
+ return sprintf(buf, "%s\n", name_str);
+
+ return -EINVAL;
+}
+
+static MDEV_TYPE_ATTR_RO(name);
+
+static ssize_t
+available_instances_show(struct kobject *kobj, struct device *dev, char *buf)
+{
+ return sprintf(buf, "%d\n", INT_MAX);
+}
+
+static MDEV_TYPE_ATTR_RO(available_instances);
+
+static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
+ char *buf)
+{
+ return sprintf(buf, "%s\n", VIRTIO_MDEV_DEVICE_API_STRING);
+}
+
+static MDEV_TYPE_ATTR_RO(device_api);
+
+static struct attribute *mdev_types_attrs[] = {
+ &mdev_type_attr_name.attr,
+ &mdev_type_attr_device_api.attr,
+ &mdev_type_attr_available_instances.attr,
+ NULL,
+};
+
+static struct attribute_group mdev_type_group = {
+ .name = "virtio",
+ .attrs = mdev_types_attrs,
+};
+
+/* TBD: "vhost" type */
+
+static struct attribute_group *mdev_type_groups[] = {
+ &mdev_type_group,
+ NULL,
+};
+
+static int mvnet_set_vq_address(struct mdev_device *mdev, u16 idx,
+ u64 desc_area, u64 driver_area, u64 device_area)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ vq->desc_addr = desc_area;
+ vq->driver_addr = driver_area;
+ vq->device_addr = device_area;
+
+ return 0;
+}
+
+static void mvnet_set_vq_num(struct mdev_device *mdev, u16 idx, u32 num)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ vq->num = num;
+}
+
+static void mvnet_kick_vq(struct mdev_device *mdev, u16 idx)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ if (vq->ready)
+ schedule_work(&mvnet->work);
+}
+
+static void mvnet_set_vq_cb(struct mdev_device *mdev, u16 idx,
+ struct virtio_mdev_callback *cb)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ vq->cb = cb->callback;
+ vq->private = cb->private;
+}
+
+static void mvnet_set_vq_ready(struct mdev_device *mdev, u16 idx, bool ready)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ spin_lock(&mvnet->lock);
+ vq->ready = ready;
+ if (vq->ready)
+ mvnet_queue_ready(mvnet, idx);
+ spin_unlock(&mvnet->lock);
+}
+
+static bool mvnet_get_vq_ready(struct mdev_device *mdev, u16 idx)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+
+ return vq->ready;
+}
+
+static int mvnet_set_vq_state(struct mdev_device *mdev, u16 idx, u64 state)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+ struct vringh *vrh = &vq->vring;
+
+ spin_lock(&mvnet->lock);
+ vrh->last_avail_idx = state;
+ spin_unlock(&mvnet->lock);
+
+ return 0;
+}
+
+static u64 mvnet_get_vq_state(struct mdev_device *mdev, u16 idx)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+ struct mvnet_virtqueue *vq = &mvnet->vqs[idx];
+ struct vringh *vrh = &vq->vring;
+
+ return vrh->last_avail_idx;
+}
+
+static u16 mvnet_get_vq_align(struct mdev_device *mdev)
+{
+ return MVNET_QUEUE_ALIGN;
+}
+
+static u64 mvnet_get_features(struct mdev_device *mdev)
+{
+ return mvnet_features;
+}
+
+static int mvnet_set_features(struct mdev_device *mdev, u64 features)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ /* DMA mapping must be done by driver */
+ if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
+ return -EINVAL;
+
+ mvnet->features = features & mvnet_features;
+
+ return 0;
+}
+
+static void mvnet_set_config_cb(struct mdev_device *mdev,
+ struct virtio_mdev_callback *cb)
+{
+ /* We don't support config interrupt */
+}
+
+static u16 mvnet_get_vq_num_max(struct mdev_device *mdev)
+{
+ return MVNET_QUEUE_MAX;
+}
+
+static u32 mvnet_get_device_id(struct mdev_device *mdev)
+{
+ return MVNET_DEVICE_ID;
+}
+
+static u32 mvnet_get_vendor_id(struct mdev_device *mdev)
+{
+ return MVNET_VENDOR_ID;
+}
+
+static u8 mvnet_get_status(struct mdev_device *mdev)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ return mvnet->status;
+}
+
+static void mvnet_set_status(struct mdev_device *mdev, u8 status)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ mvnet->status = status;
+
+ if (status == 0) {
+ spin_lock(&mvnet->lock);
+ mvnet_reset(mvnet);
+ spin_unlock(&mvnet->lock);
+ }
+}
+
+static void mvnet_get_config(struct mdev_device *mdev, unsigned int offset,
+ void *buf, unsigned int len)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ if (offset + len < sizeof(struct virtio_net_config))
+ memcpy(buf, &mvnet->config + offset, len);
+}
+
+static void mvnet_set_config(struct mdev_device *mdev, unsigned int offset,
+ const void *buf, unsigned int len)
+{
+ /* No writable config supportted by mvnet */
+}
+
+static u64 mvnet_get_mdev_features(struct mdev_device *mdev)
+{
+ return VIRTIO_MDEV_F_VERSION_1;
+}
+
+static u32 mvnet_get_generation(struct mdev_device *mdev)
+{
+ struct mvnet_state *mvnet = mdev_get_drvdata(mdev);
+
+ return mvnet->generation;
+}
+
+static const struct virtio_mdev_device_ops virtio_mdev_ops = {
+ .set_vq_address = mvnet_set_vq_address,
+ .set_vq_num = mvnet_set_vq_num,
+ .kick_vq = mvnet_kick_vq,
+ .set_vq_cb = mvnet_set_vq_cb,
+ .set_vq_ready = mvnet_set_vq_ready,
+ .get_vq_ready = mvnet_get_vq_ready,
+ .set_vq_state = mvnet_set_vq_state,
+ .get_vq_state = mvnet_get_vq_state,
+ .get_vq_align = mvnet_get_vq_align,
+ .get_features = mvnet_get_features,
+ .set_features = mvnet_set_features,
+ .set_config_cb = mvnet_set_config_cb,
+ .get_vq_num_max = mvnet_get_vq_num_max,
+ .get_device_id = mvnet_get_device_id,
+ .get_vendor_id = mvnet_get_vendor_id,
+ .get_status = mvnet_get_status,
+ .set_status = mvnet_set_status,
+ .get_config = mvnet_get_config,
+ .set_config = mvnet_set_config,
+ .get_mdev_features = mvnet_get_mdev_features,
+ .get_generation = mvnet_get_generation,
+};
+
+static const struct mdev_parent_ops mdev_fops = {
+ .owner = THIS_MODULE,
+ .dev_attr_groups = mvnet_dev_groups,
+ .mdev_attr_groups = mdev_dev_groups,
+ .supported_type_groups = mdev_type_groups,
+ .create = mvnet_create,
+ .remove = mvnet_remove,
+};
+
+static void mvnet_device_release(struct device *dev)
+{
+ dev_dbg(dev, "mvnet: released\n");
+}
+
+static int __init mvnet_dev_init(void)
+{
+ int ret = 0;
+
+ pr_info("mvnet_dev: %s\n", __func__);
+
+ memset(&mvnet_dev, 0, sizeof(mvnet_dev));
+
+ idr_init(&mvnet_dev.vd_idr);
+
+ mvnet_dev.vd_class = class_create(THIS_MODULE, MVNET_CLASS_NAME);
+
+ if (IS_ERR(mvnet_dev.vd_class)) {
+ pr_err("Error: failed to register mvnet_dev class\n");
+ ret = PTR_ERR(mvnet_dev.vd_class);
+ goto failed1;
+ }
+
+ mvnet_dev.dev.class = mvnet_dev.vd_class;
+ mvnet_dev.dev.release = mvnet_device_release;
+ dev_set_name(&mvnet_dev.dev, "%s", MVNET_NAME);
+
+ ret = device_register(&mvnet_dev.dev);
+ if (ret)
+ goto failed2;
+
+ ret = mdev_register_device(&mvnet_dev.dev, &mdev_fops);
+ if (ret)
+ goto failed3;
+
+ mutex_init(&mdev_list_lock);
+ INIT_LIST_HEAD(&mdev_devices_list);
+
+ goto all_done;
+
+failed3:
+
+ device_unregister(&mvnet_dev.dev);
+failed2:
+ class_destroy(mvnet_dev.vd_class);
+
+failed1:
+all_done:
+ return ret;
+}
+
+static void __exit mvnet_dev_exit(void)
+{
+ mvnet_dev.dev.bus = NULL;
+ mdev_unregister_device(&mvnet_dev.dev);
+
+ device_unregister(&mvnet_dev.dev);
+ idr_destroy(&mvnet_dev.vd_idr);
+ class_destroy(mvnet_dev.vd_class);
+ mvnet_dev.vd_class = NULL;
+ pr_info("mvnet_dev: Unloaded!\n");
+}
+
+module_init(mvnet_dev_init)
+module_exit(mvnet_dev_exit)
+
+MODULE_LICENSE("GPL v2");
+MODULE_INFO(supported, "Simulate loopback ethernet device over mdev");
+MODULE_VERSION(VERSION_STRING);
+MODULE_AUTHOR(DRIVER_AUTHOR);
--
2.19.1
^ permalink raw reply related [flat|nested] 27+ messages in thread
* Re: [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-17 10:48 ` [PATCH V4 3/6] mdev: introduce device specific ops Jason Wang
@ 2019-10-17 15:07 ` Cornelia Huck
2019-10-17 17:53 ` Alex Williamson
2019-10-18 7:34 ` Jason Wang
2019-10-20 23:41 ` Parav Pandit
1 sibling, 2 replies; 27+ messages in thread
From: Cornelia Huck @ 2019-10-17 15:07 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On Thu, 17 Oct 2019 18:48:33 +0800
Jason Wang <jasowang@redhat.com> 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@redhat.com>
> ---
> .../driver-api/vfio-mediated-device.rst | 25 +++++----
> 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 | 18 +++++--
> drivers/vfio/mdev/mdev_private.h | 1 +
> drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
> include/linux/mdev.h | 45 ++++------------
> include/linux/vfio_mdev.h | 52 +++++++++++++++++++
> samples/vfio-mdev/mbochs.c | 20 ++++---
> samples/vfio-mdev/mdpy.c | 20 ++++---
> samples/vfio-mdev/mtty.c | 18 ++++---
> 13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
> --- a/Documentation/driver-api/vfio-mediated-device.rst
> +++ b/Documentation/driver-api/vfio-mediated-device.rst
> @@ -152,11 +152,22 @@ 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:
> -
> -* open: open callback of mediated device
> -* close: close callback of mediated device
> -* ioctl: ioctl callback of mediated device
> +As multiple types of mediated devices may be supported, the device
> +must set up the class id and the device specific callbacks in create()
s/in create()/in the create()/
> +callback. E.g for vfio-mdev device it needs to be done through:
"Each class provides a helper function to do so; e.g. for vfio-mdev
devices, the function to be called is:"
?
> +
> + int mdev_set_vfio_ops(struct mdev_device *mdev,
> + const struct vfio_mdev_ops *vfio_ops);
> +
> +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device
"(set by this helper function to MDEV_CLASS_ID_VFIO)" ?
> +with an mdev driver via its id table. The device specific callbacks
> +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
"(specified in *vfio_ops by the caller)" ?
> +the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
> +uses the following device-specific ops:
> +
> +* 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
> @@ -167,10 +178,6 @@ 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 in create() callback through::
> -
> - int mdev_set_class(struct mdev_device *mdev, u16 id);
> -
I'm wondering if this patch set should start out with introducing
helper functions already (i.e. don't introduce mdev_set_class(), but
start out with mdev_set_class_vfio() which will gain the *vfio_ops
argument in this patch.)
> 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::
>
(...)
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index 3a9c52d71b4e..d0f3113c8071 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data)
> }
> EXPORT_SYMBOL(mdev_set_drvdata);
>
> -/* Specify the class for the mdev device, this must be called during
> - * create() callback.
> +/* Specify the VFIO device ops for the mdev device, this
> + * must be called during create() callback for VFIO mdev device.
> */
/*
* Specify the mdev device to be a VFIO mdev device, and set the
* VFIO devices ops for it. This must be called from the create()
* callback for VFIO mdev devices.
*/
?
> -void mdev_set_class(struct mdev_device *mdev, u16 id)
> +void mdev_set_vfio_ops(struct mdev_device *mdev,
> + const struct vfio_mdev_device_ops *vfio_ops)
> {
> WARN_ON(mdev->class_id);
> - mdev->class_id = id;
> + mdev->class_id = MDEV_CLASS_ID_VFIO;
> + mdev->device_ops = vfio_ops;
> }
> -EXPORT_SYMBOL(mdev_set_class);
> +EXPORT_SYMBOL(mdev_set_vfio_ops);
> +
> +const void *mdev_get_dev_ops(struct mdev_device *mdev)
> +{
> + return mdev->device_ops;
> +}
> +EXPORT_SYMBOL(mdev_get_dev_ops);
>
> struct device *mdev_dev(struct mdev_device *mdev)
> {
(...)
The code change looks good to me; I'm just wondering if we should
introduce mdev_set_class() at all (see above).
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-17 15:07 ` Cornelia Huck
@ 2019-10-17 17:53 ` Alex Williamson
2019-10-18 7:44 ` Cornelia Huck
2019-10-18 7:34 ` Jason Wang
1 sibling, 1 reply; 27+ messages in thread
From: Alex Williamson @ 2019-10-17 17:53 UTC (permalink / raw)
To: Cornelia Huck
Cc: Jason Wang, kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, mst, tiwei.bie, virtualization, netdev,
maxime.coquelin, cunming.liang, zhihong.wang, rob.miller,
xiao.w.wang, haotian.wang, zhenyuw, zhi.a.wang, jani.nikula,
joonas.lahtinen, rodrigo.vivi, airlied, daniel, farman, pasic,
sebott, oberpar, heiko.carstens, gor, borntraeger, akrowiak,
freude, lingshan.zhu, idos, eperezma, lulu, parav,
christophe.de.dinechin, kevin.tian, stefanha
On Thu, 17 Oct 2019 17:07:55 +0200
Cornelia Huck <cohuck@redhat.com> wrote:
> On Thu, 17 Oct 2019 18:48:33 +0800
> Jason Wang <jasowang@redhat.com> 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@redhat.com>
> > ---
> > .../driver-api/vfio-mediated-device.rst | 25 +++++----
> > 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 | 18 +++++--
> > drivers/vfio/mdev/mdev_private.h | 1 +
> > drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
> > include/linux/mdev.h | 45 ++++------------
> > include/linux/vfio_mdev.h | 52 +++++++++++++++++++
> > samples/vfio-mdev/mbochs.c | 20 ++++---
> > samples/vfio-mdev/mdpy.c | 20 ++++---
> > samples/vfio-mdev/mtty.c | 18 ++++---
> > 13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
> > --- a/Documentation/driver-api/vfio-mediated-device.rst
> > +++ b/Documentation/driver-api/vfio-mediated-device.rst
> > @@ -152,11 +152,22 @@ 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:
> > -
> > -* open: open callback of mediated device
> > -* close: close callback of mediated device
> > -* ioctl: ioctl callback of mediated device
> > +As multiple types of mediated devices may be supported, the device
> > +must set up the class id and the device specific callbacks in create()
>
> s/in create()/in the create()/
>
> > +callback. E.g for vfio-mdev device it needs to be done through:
>
> "Each class provides a helper function to do so; e.g. for vfio-mdev
> devices, the function to be called is:"
>
> ?
>
> > +
> > + int mdev_set_vfio_ops(struct mdev_device *mdev,
> > + const struct vfio_mdev_ops *vfio_ops);
> > +
> > +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device
>
> "(set by this helper function to MDEV_CLASS_ID_VFIO)" ?
>
> > +with an mdev driver via its id table. The device specific callbacks
> > +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
>
> "(specified in *vfio_ops by the caller)" ?
>
> > +the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
> > +uses the following device-specific ops:
> > +
> > +* 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
> > @@ -167,10 +178,6 @@ 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 in create() callback through::
> > -
> > - int mdev_set_class(struct mdev_device *mdev, u16 id);
> > -
>
> I'm wondering if this patch set should start out with introducing
> helper functions already (i.e. don't introduce mdev_set_class(), but
> start out with mdev_set_class_vfio() which will gain the *vfio_ops
> argument in this patch.)
Yes, it would be cleaner, but is it really worth the churn? Correct me
if I'm wrong, but I think we get to the same point after this patch and
aside from the function name itself, the difference is really just that
the class_id is briefly exposed to the parent driver, right? Thanks,
Alex
> > 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::
> >
>
> (...)
>
> > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> > index 3a9c52d71b4e..d0f3113c8071 100644
> > --- a/drivers/vfio/mdev/mdev_core.c
> > +++ b/drivers/vfio/mdev/mdev_core.c
> > @@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data)
> > }
> > EXPORT_SYMBOL(mdev_set_drvdata);
> >
> > -/* Specify the class for the mdev device, this must be called during
> > - * create() callback.
> > +/* Specify the VFIO device ops for the mdev device, this
> > + * must be called during create() callback for VFIO mdev device.
> > */
>
> /*
> * Specify the mdev device to be a VFIO mdev device, and set the
> * VFIO devices ops for it. This must be called from the create()
> * callback for VFIO mdev devices.
> */
>
> ?
>
> > -void mdev_set_class(struct mdev_device *mdev, u16 id)
> > +void mdev_set_vfio_ops(struct mdev_device *mdev,
> > + const struct vfio_mdev_device_ops *vfio_ops)
> > {
> > WARN_ON(mdev->class_id);
> > - mdev->class_id = id;
> > + mdev->class_id = MDEV_CLASS_ID_VFIO;
> > + mdev->device_ops = vfio_ops;
> > }
> > -EXPORT_SYMBOL(mdev_set_class);
> > +EXPORT_SYMBOL(mdev_set_vfio_ops);
> > +
> > +const void *mdev_get_dev_ops(struct mdev_device *mdev)
> > +{
> > + return mdev->device_ops;
> > +}
> > +EXPORT_SYMBOL(mdev_get_dev_ops);
> >
> > struct device *mdev_dev(struct mdev_device *mdev)
> > {
>
> (...)
>
> The code change looks good to me; I'm just wondering if we should
> introduce mdev_set_class() at all (see above).
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-17 10:48 ` [PATCH V4 4/6] mdev: introduce virtio device and its device ops Jason Wang
@ 2019-10-17 17:53 ` Alex Williamson
2019-10-18 7:35 ` Jason Wang
2019-10-18 9:46 ` Cornelia Huck
2019-10-18 9:46 ` Tiwei Bie
2 siblings, 1 reply; 27+ messages in thread
From: Alex Williamson @ 2019-10-17 17:53 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, mst, tiwei.bie, virtualization, netdev,
cohuck, maxime.coquelin, cunming.liang, zhihong.wang, rob.miller,
xiao.w.wang, haotian.wang, zhenyuw, zhi.a.wang, jani.nikula,
joonas.lahtinen, rodrigo.vivi, airlied, daniel, farman, pasic,
sebott, oberpar, heiko.carstens, gor, borntraeger, akrowiak,
freude, lingshan.zhu, idos, eperezma, lulu, parav,
christophe.de.dinechin, kevin.tian, stefanha
On Thu, 17 Oct 2019 18:48:34 +0800
Jason Wang <jasowang@redhat.com> wrote:
> This patch implements basic support for mdev driver that supports
> virtio transport for kernel virtio driver.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vfio/mdev/mdev_core.c | 12 +++
> include/linux/mdev.h | 4 +
> include/linux/virtio_mdev.h | 151 ++++++++++++++++++++++++++++++++++
> 3 files changed, 167 insertions(+)
> create mode 100644 include/linux/virtio_mdev.h
>
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index d0f3113c8071..5834f6b7c7a5 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -57,6 +57,18 @@ void mdev_set_vfio_ops(struct mdev_device *mdev,
> }
> EXPORT_SYMBOL(mdev_set_vfio_ops);
>
> +/* Specify the virtio device ops for the mdev device, this
> + * must be called during create() callback for virtio mdev device.
> + */
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops)
> +{
> + BUG_ON(mdev->class_id);
Nit, this one is a BUG_ON, but the vfio one is a WARN_ON. Thanks,
Alex
> + mdev->class_id = MDEV_CLASS_ID_VIRTIO;
> + mdev->device_ops = virtio_ops;
> +}
> +EXPORT_SYMBOL(mdev_set_virtio_ops);
> +
> const void *mdev_get_dev_ops(struct mdev_device *mdev)
> {
> return mdev->device_ops;
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 3d29e09e20c9..13e045e09d3b 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -17,6 +17,7 @@
>
> struct mdev_device;
> struct vfio_mdev_device_ops;
> +struct virtio_mdev_device_ops;
>
> /*
> * Called by the parent device driver to set the device which represents
> @@ -111,6 +112,8 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data);
> const guid_t *mdev_uuid(struct mdev_device *mdev);
> void mdev_set_vfio_ops(struct mdev_device *mdev,
> const struct vfio_mdev_device_ops *vfio_ops);
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops);
> const void *mdev_get_dev_ops(struct mdev_device *mdev);
>
> extern struct bus_type mdev_bus_type;
> @@ -127,6 +130,7 @@ struct mdev_device *mdev_from_dev(struct device *dev);
>
> enum {
> MDEV_CLASS_ID_VFIO = 1,
> + MDEV_CLASS_ID_VIRTIO = 2,
> /* New entries must be added here */
> };
>
> diff --git a/include/linux/virtio_mdev.h b/include/linux/virtio_mdev.h
> new file mode 100644
> index 000000000000..b965b50f9b24
> --- /dev/null
> +++ b/include/linux/virtio_mdev.h
> @@ -0,0 +1,151 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Virtio mediated device driver
> + *
> + * Copyright 2019, Red Hat Corp.
> + * Author: Jason Wang <jasowang@redhat.com>
> + */
> +#ifndef _LINUX_VIRTIO_MDEV_H
> +#define _LINUX_VIRTIO_MDEV_H
> +
> +#include <linux/interrupt.h>
> +#include <linux/mdev.h>
> +#include <uapi/linux/vhost.h>
> +
> +#define VIRTIO_MDEV_DEVICE_API_STRING "virtio-mdev"
> +#define VIRTIO_MDEV_F_VERSION_1 0x1
> +
> +struct virtio_mdev_callback {
> + irqreturn_t (*callback)(void *data);
> + void *private;
> +};
> +
> +/**
> + * struct vfio_mdev_device_ops - Structure to be registered for each
> + * mdev device to register the device to virtio-mdev module.
> + *
> + * @set_vq_address: Set the address of virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @desc_area: address of desc area
> + * @driver_area: address of driver area
> + * @device_area: address of device area
> + * Returns integer: success (0) or error (< 0)
> + * @set_vq_num: Set the size of virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @num: the size of virtqueue
> + * @kick_vq: Kick the virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @set_vq_cb: Set the interrupt callback function for
> + * a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @cb: virtio-mdev interrupt callback structure
> + * @set_vq_ready: Set ready status for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @ready: ready (true) not ready(false)
> + * @get_vq_ready: Get ready status for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * Returns boolean: ready (true) or not (false)
> + * @set_vq_state: Set the state for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @state: virtqueue state (last_avail_idx)
> + * Returns integer: success (0) or error (< 0)
> + * @get_vq_state: Get the state for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * Returns virtqueue state (last_avail_idx)
> + * @get_vq_align: Get the virtqueue align requirement
> + * for the device
> + * @mdev: mediated device
> + * Returns virtqueue algin requirement
> + * @get_features: Get virtio features supported by the device
> + * @mdev: mediated device
> + * Returns the virtio features support by the
> + * device
> + * @get_features: Set virtio features supported by the driver
> + * @mdev: mediated device
> + * @features: feature support by the driver
> + * Returns integer: success (0) or error (< 0)
> + * @set_config_cb: Set the config interrupt callback
> + * @mdev: mediated device
> + * @cb: virtio-mdev interrupt callback structure
> + * @get_vq_num_max: Get the max size of virtqueue
> + * @mdev: mediated device
> + * Returns u16: max size of virtqueue
> + * @get_device_id: Get virtio device id
> + * @mdev: mediated device
> + * Returns u32: virtio device id
> + * @get_vendor_id: Get virtio vendor id
> + * @mdev: mediated device
> + * Returns u32: virtio vendor id
> + * @get_status: Get the device status
> + * @mdev: mediated device
> + * Returns u8: virtio device status
> + * @set_status: Set the device status
> + * @mdev: mediated device
> + * @status: virtio device status
> + * @get_config: Read from device specific configuration space
> + * @mdev: mediated device
> + * @offset: offset from the beginning of
> + * configuration space
> + * @buf: buffer used to read to
> + * @len: the length to read from
> + * configration space
> + * @set_config: Write to device specific configuration space
> + * @mdev: mediated device
> + * @offset: offset from the beginning of
> + * configuration space
> + * @buf: buffer used to write from
> + * @len: the length to write to
> + * configration space
> + * @get_mdev_features: Get the feature of virtio mdev device
> + * @mdev: mediated device
> + * Returns the mdev features (API) support by
> + * the device.
> + * @get_generation: Get device generaton
> + * @mdev: mediated device
> + * Returns u32: device generation
> + */
> +struct virtio_mdev_device_ops {
> + /* Virtqueue ops */
> + int (*set_vq_address)(struct mdev_device *mdev,
> + u16 idx, u64 desc_area, u64 driver_area,
> + u64 device_area);
> + void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
> + void (*kick_vq)(struct mdev_device *mdev, u16 idx);
> + void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
> + struct virtio_mdev_callback *cb);
> + void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
> + bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
> + int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
> + u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
> +
> + /* Device ops */
> + u16 (*get_vq_align)(struct mdev_device *mdev);
> + u64 (*get_features)(struct mdev_device *mdev);
> + int (*set_features)(struct mdev_device *mdev, u64 features);
> + void (*set_config_cb)(struct mdev_device *mdev,
> + struct virtio_mdev_callback *cb);
> + u16 (*get_vq_num_max)(struct mdev_device *mdev);
> + u32 (*get_device_id)(struct mdev_device *mdev);
> + u32 (*get_vendor_id)(struct mdev_device *mdev);
> + u8 (*get_status)(struct mdev_device *mdev);
> + void (*set_status)(struct mdev_device *mdev, u8 status);
> + void (*get_config)(struct mdev_device *mdev, unsigned int offset,
> + void *buf, unsigned int len);
> + void (*set_config)(struct mdev_device *mdev, unsigned int offset,
> + const void *buf, unsigned int len);
> + u64 (*get_mdev_features)(struct mdev_device *mdev);
> + u32 (*get_generation)(struct mdev_device *mdev);
> +};
> +
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops);
> +
> +#endif
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-17 15:07 ` Cornelia Huck
2019-10-17 17:53 ` Alex Williamson
@ 2019-10-18 7:34 ` Jason Wang
1 sibling, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-18 7:34 UTC (permalink / raw)
To: Cornelia Huck
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/17 下午11:07, Cornelia Huck wrote:
> On Thu, 17 Oct 2019 18:48:33 +0800
> Jason Wang <jasowang@redhat.com> 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@redhat.com>
>> ---
>> .../driver-api/vfio-mediated-device.rst | 25 +++++----
>> 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 | 18 +++++--
>> drivers/vfio/mdev/mdev_private.h | 1 +
>> drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
>> include/linux/mdev.h | 45 ++++------------
>> include/linux/vfio_mdev.h | 52 +++++++++++++++++++
>> samples/vfio-mdev/mbochs.c | 20 ++++---
>> samples/vfio-mdev/mdpy.c | 20 ++++---
>> samples/vfio-mdev/mtty.c | 18 ++++---
>> 13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
>> --- a/Documentation/driver-api/vfio-mediated-device.rst
>> +++ b/Documentation/driver-api/vfio-mediated-device.rst
>> @@ -152,11 +152,22 @@ 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:
>> -
>> -* open: open callback of mediated device
>> -* close: close callback of mediated device
>> -* ioctl: ioctl callback of mediated device
>> +As multiple types of mediated devices may be supported, the device
>> +must set up the class id and the device specific callbacks in create()
> s/in create()/in the create()/
Will fix.
>
>> +callback. E.g for vfio-mdev device it needs to be done through:
> "Each class provides a helper function to do so; e.g. for vfio-mdev
> devices, the function to be called is:"
>
> ?
This looks better.
>
>> +
>> + int mdev_set_vfio_ops(struct mdev_device *mdev,
>> + const struct vfio_mdev_ops *vfio_ops);
>> +
>> +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device
> "(set by this helper function to MDEV_CLASS_ID_VFIO)" ?
Yes.
>> +with an mdev driver via its id table. The device specific callbacks
>> +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
> "(specified in *vfio_ops by the caller)" ?
Yes.
>> +the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
>> +uses the following device-specific ops:
>> +
>> +* 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
>> @@ -167,10 +178,6 @@ 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 in create() callback through::
>> -
>> - int mdev_set_class(struct mdev_device *mdev, u16 id);
>> -
> I'm wondering if this patch set should start out with introducing
> helper functions already (i.e. don't introduce mdev_set_class(), but
> start out with mdev_set_class_vfio() which will gain the *vfio_ops
> argument in this patch.)
I think it doesn't harm to keep it as is since in patch 1 we introduce
class_id and bus match method based on that without device ops there.
But if you stick I can change.
Thanks
>
>> 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::
>>
> (...)
>
>> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
>> index 3a9c52d71b4e..d0f3113c8071 100644
>> --- a/drivers/vfio/mdev/mdev_core.c
>> +++ b/drivers/vfio/mdev/mdev_core.c
>> @@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *data)
>> }
>> EXPORT_SYMBOL(mdev_set_drvdata);
>>
>> -/* Specify the class for the mdev device, this must be called during
>> - * create() callback.
>> +/* Specify the VFIO device ops for the mdev device, this
>> + * must be called during create() callback for VFIO mdev device.
>> */
> /*
> * Specify the mdev device to be a VFIO mdev device, and set the
> * VFIO devices ops for it. This must be called from the create()
> * callback for VFIO mdev devices.
> */
>
> ?
>
>> -void mdev_set_class(struct mdev_device *mdev, u16 id)
>> +void mdev_set_vfio_ops(struct mdev_device *mdev,
>> + const struct vfio_mdev_device_ops *vfio_ops)
>> {
>> WARN_ON(mdev->class_id);
>> - mdev->class_id = id;
>> + mdev->class_id = MDEV_CLASS_ID_VFIO;
>> + mdev->device_ops = vfio_ops;
>> }
>> -EXPORT_SYMBOL(mdev_set_class);
>> +EXPORT_SYMBOL(mdev_set_vfio_ops);
>> +
>> +const void *mdev_get_dev_ops(struct mdev_device *mdev)
>> +{
>> + return mdev->device_ops;
>> +}
>> +EXPORT_SYMBOL(mdev_get_dev_ops);
>>
>> struct device *mdev_dev(struct mdev_device *mdev)
>> {
> (...)
>
> The code change looks good to me; I'm just wondering if we should
> introduce mdev_set_class() at all (see above).
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-17 17:53 ` Alex Williamson
@ 2019-10-18 7:35 ` Jason Wang
0 siblings, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-18 7:35 UTC (permalink / raw)
To: Alex Williamson
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, mst, tiwei.bie, virtualization, netdev,
cohuck, maxime.coquelin, cunming.liang, zhihong.wang, rob.miller,
xiao.w.wang, haotian.wang, zhenyuw, zhi.a.wang, jani.nikula,
joonas.lahtinen, rodrigo.vivi, airlied, daniel, farman, pasic,
sebott, oberpar, heiko.carstens, gor, borntraeger, akrowiak,
freude, lingshan.zhu, idos, eperezma, lulu, parav,
christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/18 上午1:53, Alex Williamson wrote:
> On Thu, 17 Oct 2019 18:48:34 +0800
> Jason Wang<jasowang@redhat.com> wrote:
>
>> This patch implements basic support for mdev driver that supports
>> virtio transport for kernel virtio driver.
>>
>> Signed-off-by: Jason Wang<jasowang@redhat.com>
>> ---
>> drivers/vfio/mdev/mdev_core.c | 12 +++
>> include/linux/mdev.h | 4 +
>> include/linux/virtio_mdev.h | 151 ++++++++++++++++++++++++++++++++++
>> 3 files changed, 167 insertions(+)
>> create mode 100644 include/linux/virtio_mdev.h
>>
>> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
>> index d0f3113c8071..5834f6b7c7a5 100644
>> --- a/drivers/vfio/mdev/mdev_core.c
>> +++ b/drivers/vfio/mdev/mdev_core.c
>> @@ -57,6 +57,18 @@ void mdev_set_vfio_ops(struct mdev_device *mdev,
>> }
>> EXPORT_SYMBOL(mdev_set_vfio_ops);
>>
>> +/* Specify the virtio device ops for the mdev device, this
>> + * must be called during create() callback for virtio mdev device.
>> + */
>> +void mdev_set_virtio_ops(struct mdev_device *mdev,
>> + const struct virtio_mdev_device_ops *virtio_ops)
>> +{
>> + BUG_ON(mdev->class_id);
> Nit, this one is a BUG_ON, but the vfio one is a WARN_ON. Thanks,
>
> Alex
Let me fix in next version.
Thanks
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-17 17:53 ` Alex Williamson
@ 2019-10-18 7:44 ` Cornelia Huck
0 siblings, 0 replies; 27+ messages in thread
From: Cornelia Huck @ 2019-10-18 7:44 UTC (permalink / raw)
To: Alex Williamson
Cc: Jason Wang, kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, mst, tiwei.bie, virtualization, netdev,
maxime.coquelin, cunming.liang, zhihong.wang, rob.miller,
xiao.w.wang, haotian.wang, zhenyuw, zhi.a.wang, jani.nikula,
joonas.lahtinen, rodrigo.vivi, airlied, daniel, farman, pasic,
sebott, oberpar, heiko.carstens, gor, borntraeger, akrowiak,
freude, lingshan.zhu, idos, eperezma, lulu, parav,
christophe.de.dinechin, kevin.tian, stefanha
On Thu, 17 Oct 2019 11:53:10 -0600
Alex Williamson <alex.williamson@redhat.com> wrote:
> On Thu, 17 Oct 2019 17:07:55 +0200
> Cornelia Huck <cohuck@redhat.com> wrote:
>
> > On Thu, 17 Oct 2019 18:48:33 +0800
> > Jason Wang <jasowang@redhat.com> 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@redhat.com>
> > > ---
> > > .../driver-api/vfio-mediated-device.rst | 25 +++++----
> > > 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 | 18 +++++--
> > > drivers/vfio/mdev/mdev_private.h | 1 +
> > > drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
> > > include/linux/mdev.h | 45 ++++------------
> > > include/linux/vfio_mdev.h | 52 +++++++++++++++++++
> > > samples/vfio-mdev/mbochs.c | 20 ++++---
> > > samples/vfio-mdev/mdpy.c | 20 ++++---
> > > samples/vfio-mdev/mtty.c | 18 ++++---
> > > 13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
> > > --- a/Documentation/driver-api/vfio-mediated-device.rst
> > > +++ b/Documentation/driver-api/vfio-mediated-device.rst
> > > @@ -152,11 +152,22 @@ 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:
> > > -
> > > -* open: open callback of mediated device
> > > -* close: close callback of mediated device
> > > -* ioctl: ioctl callback of mediated device
> > > +As multiple types of mediated devices may be supported, the device
> > > +must set up the class id and the device specific callbacks in create()
> >
> > s/in create()/in the create()/
> >
> > > +callback. E.g for vfio-mdev device it needs to be done through:
> >
> > "Each class provides a helper function to do so; e.g. for vfio-mdev
> > devices, the function to be called is:"
> >
> > ?
> >
> > > +
> > > + int mdev_set_vfio_ops(struct mdev_device *mdev,
> > > + const struct vfio_mdev_ops *vfio_ops);
> > > +
> > > +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device
> >
> > "(set by this helper function to MDEV_CLASS_ID_VFIO)" ?
> >
> > > +with an mdev driver via its id table. The device specific callbacks
> > > +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
> >
> > "(specified in *vfio_ops by the caller)" ?
> >
> > > +the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
> > > +uses the following device-specific ops:
> > > +
> > > +* 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
> > > @@ -167,10 +178,6 @@ 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 in create() callback through::
> > > -
> > > - int mdev_set_class(struct mdev_device *mdev, u16 id);
> > > -
> >
> > I'm wondering if this patch set should start out with introducing
> > helper functions already (i.e. don't introduce mdev_set_class(), but
> > start out with mdev_set_class_vfio() which will gain the *vfio_ops
> > argument in this patch.)
>
> Yes, it would be cleaner, but is it really worth the churn? Correct me
> if I'm wrong, but I think we get to the same point after this patch and
> aside from the function name itself, the difference is really just that
> the class_id is briefly exposed to the parent driver, right? Thanks,
Yes, it does not really matter much. If there's no other reason to
rework things, I'd just keep this as it is now.
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-17 10:48 ` [PATCH V4 4/6] mdev: introduce virtio device and its device ops Jason Wang
2019-10-17 17:53 ` Alex Williamson
@ 2019-10-18 9:46 ` Cornelia Huck
2019-10-18 10:55 ` Jason Wang
2019-10-18 9:46 ` Tiwei Bie
2 siblings, 1 reply; 27+ messages in thread
From: Cornelia Huck @ 2019-10-18 9:46 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On Thu, 17 Oct 2019 18:48:34 +0800
Jason Wang <jasowang@redhat.com> wrote:
> This patch implements basic support for mdev driver that supports
> virtio transport for kernel virtio driver.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vfio/mdev/mdev_core.c | 12 +++
> include/linux/mdev.h | 4 +
> include/linux/virtio_mdev.h | 151 ++++++++++++++++++++++++++++++++++
> 3 files changed, 167 insertions(+)
> create mode 100644 include/linux/virtio_mdev.h
>
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index d0f3113c8071..5834f6b7c7a5 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -57,6 +57,18 @@ void mdev_set_vfio_ops(struct mdev_device *mdev,
> }
> EXPORT_SYMBOL(mdev_set_vfio_ops);
>
> +/* Specify the virtio device ops for the mdev device, this
> + * must be called during create() callback for virtio mdev device.
> + */
Change this as for the vfio comment (last patch?)
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops)
> +{
> + BUG_ON(mdev->class_id);
s/BUG_ON/WARN_ON/
> + mdev->class_id = MDEV_CLASS_ID_VIRTIO;
> + mdev->device_ops = virtio_ops;
> +}
> +EXPORT_SYMBOL(mdev_set_virtio_ops);
> +
> const void *mdev_get_dev_ops(struct mdev_device *mdev)
> {
> return mdev->device_ops;
(...)
> diff --git a/include/linux/virtio_mdev.h b/include/linux/virtio_mdev.h
> new file mode 100644
> index 000000000000..b965b50f9b24
> --- /dev/null
> +++ b/include/linux/virtio_mdev.h
> @@ -0,0 +1,151 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Virtio mediated device driver
> + *
> + * Copyright 2019, Red Hat Corp.
> + * Author: Jason Wang <jasowang@redhat.com>
> + */
> +#ifndef _LINUX_VIRTIO_MDEV_H
> +#define _LINUX_VIRTIO_MDEV_H
> +
> +#include <linux/interrupt.h>
> +#include <linux/mdev.h>
> +#include <uapi/linux/vhost.h>
> +
> +#define VIRTIO_MDEV_DEVICE_API_STRING "virtio-mdev"
> +#define VIRTIO_MDEV_F_VERSION_1 0x1
> +
> +struct virtio_mdev_callback {
> + irqreturn_t (*callback)(void *data);
> + void *private;
> +};
> +
> +/**
> + * struct vfio_mdev_device_ops - Structure to be registered for each
> + * mdev device to register the device to virtio-mdev module.
> + *
> + * @set_vq_address: Set the address of virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @desc_area: address of desc area
> + * @driver_area: address of driver area
> + * @device_area: address of device area
> + * Returns integer: success (0) or error (< 0)
Probably dumb question (have not read the next patches yet): Is this
agnostic regarding split or packed queues?
> + * @set_vq_num: Set the size of virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @num: the size of virtqueue
> + * @kick_vq: Kick the virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @set_vq_cb: Set the interrupt callback function for
> + * a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @cb: virtio-mdev interrupt callback structure
> + * @set_vq_ready: Set ready status for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @ready: ready (true) not ready(false)
> + * @get_vq_ready: Get ready status for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * Returns boolean: ready (true) or not (false)
> + * @set_vq_state: Set the state for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * @state: virtqueue state (last_avail_idx)
> + * Returns integer: success (0) or error (< 0)
> + * @get_vq_state: Get the state for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * Returns virtqueue state (last_avail_idx)
> + * @get_vq_align: Get the virtqueue align requirement
> + * for the device
> + * @mdev: mediated device
> + * Returns virtqueue algin requirement
> + * @get_features: Get virtio features supported by the device
> + * @mdev: mediated device
> + * Returns the virtio features support by the
> + * device
> + * @get_features: Set virtio features supported by the driver
s/get_features/set_features/
> + * @mdev: mediated device
> + * @features: feature support by the driver
> + * Returns integer: success (0) or error (< 0)
> + * @set_config_cb: Set the config interrupt callback
> + * @mdev: mediated device
> + * @cb: virtio-mdev interrupt callback structure
> + * @get_vq_num_max: Get the max size of virtqueue
> + * @mdev: mediated device
> + * Returns u16: max size of virtqueue
> + * @get_device_id: Get virtio device id
> + * @mdev: mediated device
> + * Returns u32: virtio device id
> + * @get_vendor_id: Get virtio vendor id
> + * @mdev: mediated device
> + * Returns u32: virtio vendor id
How is the vendor id defined? As for normal virtio-pci devices?
> + * @get_status: Get the device status
> + * @mdev: mediated device
> + * Returns u8: virtio device status
> + * @set_status: Set the device status
> + * @mdev: mediated device
> + * @status: virtio device status
> + * @get_config: Read from device specific configuration space
> + * @mdev: mediated device
> + * @offset: offset from the beginning of
> + * configuration space
> + * @buf: buffer used to read to
> + * @len: the length to read from
> + * configration space
> + * @set_config: Write to device specific configuration space
> + * @mdev: mediated device
> + * @offset: offset from the beginning of
> + * configuration space
> + * @buf: buffer used to write from
> + * @len: the length to write to
> + * configration space
> + * @get_mdev_features: Get the feature of virtio mdev device
> + * @mdev: mediated device
> + * Returns the mdev features (API) support by
> + * the device.
What kind of 'features' are supposed to go in there? Are these bits,
like you defined for VIRTIO_MDEV_F_VERSION_1 above?
> + * @get_generation: Get device generaton
> + * @mdev: mediated device
> + * Returns u32: device generation
Is that callback mandatory?
> + */
> +struct virtio_mdev_device_ops {
> + /* Virtqueue ops */
> + int (*set_vq_address)(struct mdev_device *mdev,
> + u16 idx, u64 desc_area, u64 driver_area,
> + u64 device_area);
> + void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
> + void (*kick_vq)(struct mdev_device *mdev, u16 idx);
> + void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
> + struct virtio_mdev_callback *cb);
> + void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
> + bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
> + int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
> + u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
> +
> + /* Device ops */
> + u16 (*get_vq_align)(struct mdev_device *mdev);
> + u64 (*get_features)(struct mdev_device *mdev);
> + int (*set_features)(struct mdev_device *mdev, u64 features);
> + void (*set_config_cb)(struct mdev_device *mdev,
> + struct virtio_mdev_callback *cb);
> + u16 (*get_vq_num_max)(struct mdev_device *mdev);
> + u32 (*get_device_id)(struct mdev_device *mdev);
> + u32 (*get_vendor_id)(struct mdev_device *mdev);
> + u8 (*get_status)(struct mdev_device *mdev);
> + void (*set_status)(struct mdev_device *mdev, u8 status);
> + void (*get_config)(struct mdev_device *mdev, unsigned int offset,
> + void *buf, unsigned int len);
> + void (*set_config)(struct mdev_device *mdev, unsigned int offset,
> + const void *buf, unsigned int len);
> + u64 (*get_mdev_features)(struct mdev_device *mdev);
> + u32 (*get_generation)(struct mdev_device *mdev);
> +};
> +
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops);
> +
> +#endif
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-17 10:48 ` [PATCH V4 4/6] mdev: introduce virtio device and its device ops Jason Wang
2019-10-17 17:53 ` Alex Williamson
2019-10-18 9:46 ` Cornelia Huck
@ 2019-10-18 9:46 ` Tiwei Bie
2019-10-18 10:57 ` Jason Wang
2 siblings, 1 reply; 27+ messages in thread
From: Tiwei Bie @ 2019-10-18 9:46 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, virtualization,
netdev, cohuck, maxime.coquelin, cunming.liang, zhihong.wang,
rob.miller, xiao.w.wang, haotian.wang, zhenyuw, zhi.a.wang,
jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied, daniel,
farman, pasic, sebott, oberpar, heiko.carstens, gor, borntraeger,
akrowiak, freude, lingshan.zhu, idos, eperezma, lulu, parav,
christophe.de.dinechin, kevin.tian, stefanha
On Thu, Oct 17, 2019 at 06:48:34PM +0800, Jason Wang wrote:
> + * @get_vq_state: Get the state for a virtqueue
> + * @mdev: mediated device
> + * @idx: virtqueue index
> + * Returns virtqueue state (last_avail_idx)
> + * @get_vq_align: Get the virtqueue align requirement
> + * for the device
> + * @mdev: mediated device
> + * Returns virtqueue algin requirement
> + * @get_features: Get virtio features supported by the device
> + * @mdev: mediated device
> + * Returns the virtio features support by the
> + * device
> + * @get_features: Set virtio features supported by the driver
s/get_features/set_features/
> + * configration space
> + * @get_mdev_features: Get the feature of virtio mdev device
> + * @mdev: mediated device
> + * Returns the mdev features (API) support by
> + * the device.
> + * @get_generation: Get device generaton
> + * @mdev: mediated device
> + * Returns u32: device generation
> + */
> +struct virtio_mdev_device_ops {
> + /* Virtqueue ops */
> + int (*set_vq_address)(struct mdev_device *mdev,
> + u16 idx, u64 desc_area, u64 driver_area,
> + u64 device_area);
> + void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
> + void (*kick_vq)(struct mdev_device *mdev, u16 idx);
> + void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
> + struct virtio_mdev_callback *cb);
> + void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
> + bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
> + int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
> + u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
> +
> + /* Device ops */
> + u16 (*get_vq_align)(struct mdev_device *mdev);
> + u64 (*get_features)(struct mdev_device *mdev);
> + int (*set_features)(struct mdev_device *mdev, u64 features);
> + void (*set_config_cb)(struct mdev_device *mdev,
> + struct virtio_mdev_callback *cb);
> + u16 (*get_vq_num_max)(struct mdev_device *mdev);
> + u32 (*get_device_id)(struct mdev_device *mdev);
> + u32 (*get_vendor_id)(struct mdev_device *mdev);
> + u8 (*get_status)(struct mdev_device *mdev);
> + void (*set_status)(struct mdev_device *mdev, u8 status);
> + void (*get_config)(struct mdev_device *mdev, unsigned int offset,
> + void *buf, unsigned int len);
> + void (*set_config)(struct mdev_device *mdev, unsigned int offset,
> + const void *buf, unsigned int len);
> + u64 (*get_mdev_features)(struct mdev_device *mdev);
Do we need a .set_mdev_features method as well?
It's not very clear what does mdev_features mean.
Does it mean the vhost backend features?
https://github.com/torvalds/linux/blob/0e2adab6cf285c41e825b6c74a3aa61324d1132c/include/uapi/linux/vhost.h#L93-L94
> + u32 (*get_generation)(struct mdev_device *mdev);
> +};
> +
> +void mdev_set_virtio_ops(struct mdev_device *mdev,
> + const struct virtio_mdev_device_ops *virtio_ops);
> +
> +#endif
> --
> 2.19.1
>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-18 9:46 ` Cornelia Huck
@ 2019-10-18 10:55 ` Jason Wang
2019-10-18 13:30 ` Cornelia Huck
0 siblings, 1 reply; 27+ messages in thread
From: Jason Wang @ 2019-10-18 10:55 UTC (permalink / raw)
To: Cornelia Huck
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/18 下午5:46, Cornelia Huck wrote:
> On Thu, 17 Oct 2019 18:48:34 +0800
> Jason Wang <jasowang@redhat.com> wrote:
>
>> This patch implements basic support for mdev driver that supports
>> virtio transport for kernel virtio driver.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>> drivers/vfio/mdev/mdev_core.c | 12 +++
>> include/linux/mdev.h | 4 +
>> include/linux/virtio_mdev.h | 151 ++++++++++++++++++++++++++++++++++
>> 3 files changed, 167 insertions(+)
>> create mode 100644 include/linux/virtio_mdev.h
>>
>> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
>> index d0f3113c8071..5834f6b7c7a5 100644
>> --- a/drivers/vfio/mdev/mdev_core.c
>> +++ b/drivers/vfio/mdev/mdev_core.c
>> @@ -57,6 +57,18 @@ void mdev_set_vfio_ops(struct mdev_device *mdev,
>> }
>> EXPORT_SYMBOL(mdev_set_vfio_ops);
>>
>> +/* Specify the virtio device ops for the mdev device, this
>> + * must be called during create() callback for virtio mdev device.
>> + */
> Change this as for the vfio comment (last patch?)
Ok.
>
>> +void mdev_set_virtio_ops(struct mdev_device *mdev,
>> + const struct virtio_mdev_device_ops *virtio_ops)
>> +{
>> + BUG_ON(mdev->class_id);
> s/BUG_ON/WARN_ON/
Yes.
>
>> + mdev->class_id = MDEV_CLASS_ID_VIRTIO;
>> + mdev->device_ops = virtio_ops;
>> +}
>> +EXPORT_SYMBOL(mdev_set_virtio_ops);
>> +
>> const void *mdev_get_dev_ops(struct mdev_device *mdev)
>> {
>> return mdev->device_ops;
> (...)
>
>> diff --git a/include/linux/virtio_mdev.h b/include/linux/virtio_mdev.h
>> new file mode 100644
>> index 000000000000..b965b50f9b24
>> --- /dev/null
>> +++ b/include/linux/virtio_mdev.h
>> @@ -0,0 +1,151 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * Virtio mediated device driver
>> + *
>> + * Copyright 2019, Red Hat Corp.
>> + * Author: Jason Wang <jasowang@redhat.com>
>> + */
>> +#ifndef _LINUX_VIRTIO_MDEV_H
>> +#define _LINUX_VIRTIO_MDEV_H
>> +
>> +#include <linux/interrupt.h>
>> +#include <linux/mdev.h>
>> +#include <uapi/linux/vhost.h>
>> +
>> +#define VIRTIO_MDEV_DEVICE_API_STRING "virtio-mdev"
>> +#define VIRTIO_MDEV_F_VERSION_1 0x1
>> +
>> +struct virtio_mdev_callback {
>> + irqreturn_t (*callback)(void *data);
>> + void *private;
>> +};
>> +
>> +/**
>> + * struct vfio_mdev_device_ops - Structure to be registered for each
>> + * mdev device to register the device to virtio-mdev module.
>> + *
>> + * @set_vq_address: Set the address of virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * @desc_area: address of desc area
>> + * @driver_area: address of driver area
>> + * @device_area: address of device area
>> + * Returns integer: success (0) or error (< 0)
> Probably dumb question (have not read the next patches yet): Is this
> agnostic regarding split or packed queues?
Yes, it is to and to be more obvious, I use the terminology from recent
spec.
>
>> + * @set_vq_num: Set the size of virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * @num: the size of virtqueue
>> + * @kick_vq: Kick the virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * @set_vq_cb: Set the interrupt callback function for
>> + * a virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * @cb: virtio-mdev interrupt callback structure
>> + * @set_vq_ready: Set ready status for a virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * @ready: ready (true) not ready(false)
>> + * @get_vq_ready: Get ready status for a virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * Returns boolean: ready (true) or not (false)
>> + * @set_vq_state: Set the state for a virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * @state: virtqueue state (last_avail_idx)
>> + * Returns integer: success (0) or error (< 0)
>> + * @get_vq_state: Get the state for a virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * Returns virtqueue state (last_avail_idx)
>> + * @get_vq_align: Get the virtqueue align requirement
>> + * for the device
>> + * @mdev: mediated device
>> + * Returns virtqueue algin requirement
>> + * @get_features: Get virtio features supported by the device
>> + * @mdev: mediated device
>> + * Returns the virtio features support by the
>> + * device
>> + * @get_features: Set virtio features supported by the driver
> s/get_features/set_features/
Will fix.
>
>> + * @mdev: mediated device
>> + * @features: feature support by the driver
>> + * Returns integer: success (0) or error (< 0)
>> + * @set_config_cb: Set the config interrupt callback
>> + * @mdev: mediated device
>> + * @cb: virtio-mdev interrupt callback structure
>> + * @get_vq_num_max: Get the max size of virtqueue
>> + * @mdev: mediated device
>> + * Returns u16: max size of virtqueue
>> + * @get_device_id: Get virtio device id
>> + * @mdev: mediated device
>> + * Returns u32: virtio device id
>> + * @get_vendor_id: Get virtio vendor id
>> + * @mdev: mediated device
>> + * Returns u32: virtio vendor id
> How is the vendor id defined? As for normal virtio-pci devices?
The vendor that provides this device. So something like this
I notice that MMIO also had this so it looks to me it's not pci specific.
>
>> + * @get_status: Get the device status
>> + * @mdev: mediated device
>> + * Returns u8: virtio device status
>> + * @set_status: Set the device status
>> + * @mdev: mediated device
>> + * @status: virtio device status
>> + * @get_config: Read from device specific configuration space
>> + * @mdev: mediated device
>> + * @offset: offset from the beginning of
>> + * configuration space
>> + * @buf: buffer used to read to
>> + * @len: the length to read from
>> + * configration space
>> + * @set_config: Write to device specific configuration space
>> + * @mdev: mediated device
>> + * @offset: offset from the beginning of
>> + * configuration space
>> + * @buf: buffer used to write from
>> + * @len: the length to write to
>> + * configration space
>> + * @get_mdev_features: Get the feature of virtio mdev device
>> + * @mdev: mediated device
>> + * Returns the mdev features (API) support by
>> + * the device.
> What kind of 'features' are supposed to go in there? Are these bits,
> like you defined for VIRTIO_MDEV_F_VERSION_1 above?
It's the API or mdev features other than virtio features. It could be
used by driver to determine the capability of the mdev device. Besides
_F_VERSION_1, we may add dirty page tracking etc which means we need new
device ops.
>
>> + * @get_generation: Get device generaton
>> + * @mdev: mediated device
>> + * Returns u32: device generation
> Is that callback mandatory?
I think so, it's hard to emulate that completely in virtio-mdev transport.
Thanks
>
>> + */
>> +struct virtio_mdev_device_ops {
>> + /* Virtqueue ops */
>> + int (*set_vq_address)(struct mdev_device *mdev,
>> + u16 idx, u64 desc_area, u64 driver_area,
>> + u64 device_area);
>> + void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
>> + void (*kick_vq)(struct mdev_device *mdev, u16 idx);
>> + void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
>> + struct virtio_mdev_callback *cb);
>> + void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
>> + bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
>> + int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
>> + u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
>> +
>> + /* Device ops */
>> + u16 (*get_vq_align)(struct mdev_device *mdev);
>> + u64 (*get_features)(struct mdev_device *mdev);
>> + int (*set_features)(struct mdev_device *mdev, u64 features);
>> + void (*set_config_cb)(struct mdev_device *mdev,
>> + struct virtio_mdev_callback *cb);
>> + u16 (*get_vq_num_max)(struct mdev_device *mdev);
>> + u32 (*get_device_id)(struct mdev_device *mdev);
>> + u32 (*get_vendor_id)(struct mdev_device *mdev);
>> + u8 (*get_status)(struct mdev_device *mdev);
>> + void (*set_status)(struct mdev_device *mdev, u8 status);
>> + void (*get_config)(struct mdev_device *mdev, unsigned int offset,
>> + void *buf, unsigned int len);
>> + void (*set_config)(struct mdev_device *mdev, unsigned int offset,
>> + const void *buf, unsigned int len);
>> + u64 (*get_mdev_features)(struct mdev_device *mdev);
>> + u32 (*get_generation)(struct mdev_device *mdev);
>> +};
>> +
>> +void mdev_set_virtio_ops(struct mdev_device *mdev,
>> + const struct virtio_mdev_device_ops *virtio_ops);
>> +
>> +#endif
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-18 9:46 ` Tiwei Bie
@ 2019-10-18 10:57 ` Jason Wang
0 siblings, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-18 10:57 UTC (permalink / raw)
To: Tiwei Bie
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, virtualization,
netdev, cohuck, maxime.coquelin, cunming.liang, zhihong.wang,
rob.miller, xiao.w.wang, haotian.wang, zhenyuw, zhi.a.wang,
jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied, daniel,
farman, pasic, sebott, oberpar, heiko.carstens, gor, borntraeger,
akrowiak, freude, lingshan.zhu, idos, eperezma, lulu, parav,
christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/18 下午5:46, Tiwei Bie wrote:
> On Thu, Oct 17, 2019 at 06:48:34PM +0800, Jason Wang wrote:
>> + * @get_vq_state: Get the state for a virtqueue
>> + * @mdev: mediated device
>> + * @idx: virtqueue index
>> + * Returns virtqueue state (last_avail_idx)
>> + * @get_vq_align: Get the virtqueue align requirement
>> + * for the device
>> + * @mdev: mediated device
>> + * Returns virtqueue algin requirement
>> + * @get_features: Get virtio features supported by the device
>> + * @mdev: mediated device
>> + * Returns the virtio features support by the
>> + * device
>> + * @get_features: Set virtio features supported by the driver
> s/get_features/set_features/
Will fix.
>
>> + * configration space
>> + * @get_mdev_features: Get the feature of virtio mdev device
>> + * @mdev: mediated device
>> + * Returns the mdev features (API) support by
>> + * the device.
>> + * @get_generation: Get device generaton
>> + * @mdev: mediated device
>> + * Returns u32: device generation
>> + */
>> +struct virtio_mdev_device_ops {
>> + /* Virtqueue ops */
>> + int (*set_vq_address)(struct mdev_device *mdev,
>> + u16 idx, u64 desc_area, u64 driver_area,
>> + u64 device_area);
>> + void (*set_vq_num)(struct mdev_device *mdev, u16 idx, u32 num);
>> + void (*kick_vq)(struct mdev_device *mdev, u16 idx);
>> + void (*set_vq_cb)(struct mdev_device *mdev, u16 idx,
>> + struct virtio_mdev_callback *cb);
>> + void (*set_vq_ready)(struct mdev_device *mdev, u16 idx, bool ready);
>> + bool (*get_vq_ready)(struct mdev_device *mdev, u16 idx);
>> + int (*set_vq_state)(struct mdev_device *mdev, u16 idx, u64 state);
>> + u64 (*get_vq_state)(struct mdev_device *mdev, u16 idx);
>> +
>> + /* Device ops */
>> + u16 (*get_vq_align)(struct mdev_device *mdev);
>> + u64 (*get_features)(struct mdev_device *mdev);
>> + int (*set_features)(struct mdev_device *mdev, u64 features);
>> + void (*set_config_cb)(struct mdev_device *mdev,
>> + struct virtio_mdev_callback *cb);
>> + u16 (*get_vq_num_max)(struct mdev_device *mdev);
>> + u32 (*get_device_id)(struct mdev_device *mdev);
>> + u32 (*get_vendor_id)(struct mdev_device *mdev);
>> + u8 (*get_status)(struct mdev_device *mdev);
>> + void (*set_status)(struct mdev_device *mdev, u8 status);
>> + void (*get_config)(struct mdev_device *mdev, unsigned int offset,
>> + void *buf, unsigned int len);
>> + void (*set_config)(struct mdev_device *mdev, unsigned int offset,
>> + const void *buf, unsigned int len);
>> + u64 (*get_mdev_features)(struct mdev_device *mdev);
> Do we need a .set_mdev_features method as well?
Good question. To me I think we may document that the API provides
backward compatibility, so there's no need for set_mdev_features. Or is
there any other chance that we need that?
>
> It's not very clear what does mdev_features mean.
> Does it mean the vhost backend features?
>
> https://github.com/torvalds/linux/blob/0e2adab6cf285c41e825b6c74a3aa61324d1132c/include/uapi/linux/vhost.h#L93-L94
Something like this, it's kind of the version of the API, except for the
_F_VERSION_1, the first user should be _F_LOG_ALL. I will add more docs
for this API.
Thanks
>
>
>> + u32 (*get_generation)(struct mdev_device *mdev);
>> +};
>> +
>> +void mdev_set_virtio_ops(struct mdev_device *mdev,
>> + const struct virtio_mdev_device_ops *virtio_ops);
>> +
>> +#endif
>> --
>> 2.19.1
>>
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-18 10:55 ` Jason Wang
@ 2019-10-18 13:30 ` Cornelia Huck
2019-10-21 5:36 ` Jason Wang
0 siblings, 1 reply; 27+ messages in thread
From: Cornelia Huck @ 2019-10-18 13:30 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On Fri, 18 Oct 2019 18:55:02 +0800
Jason Wang <jasowang@redhat.com> wrote:
> On 2019/10/18 下午5:46, Cornelia Huck wrote:
> > On Thu, 17 Oct 2019 18:48:34 +0800
> > Jason Wang <jasowang@redhat.com> wrote:
> >> + * @get_vendor_id: Get virtio vendor id
> >> + * @mdev: mediated device
> >> + * Returns u32: virtio vendor id
> > How is the vendor id defined? As for normal virtio-pci devices?
>
>
> The vendor that provides this device. So something like this
>
> I notice that MMIO also had this so it looks to me it's not pci specific.
Ok. Would be good to specify this more explicitly.
>
>
> >
> >> + * @get_status: Get the device status
> >> + * @mdev: mediated device
> >> + * Returns u8: virtio device status
> >> + * @set_status: Set the device status
> >> + * @mdev: mediated device
> >> + * @status: virtio device status
> >> + * @get_config: Read from device specific configuration space
> >> + * @mdev: mediated device
> >> + * @offset: offset from the beginning of
> >> + * configuration space
> >> + * @buf: buffer used to read to
> >> + * @len: the length to read from
> >> + * configration space
> >> + * @set_config: Write to device specific configuration space
> >> + * @mdev: mediated device
> >> + * @offset: offset from the beginning of
> >> + * configuration space
> >> + * @buf: buffer used to write from
> >> + * @len: the length to write to
> >> + * configration space
> >> + * @get_mdev_features: Get the feature of virtio mdev device
> >> + * @mdev: mediated device
> >> + * Returns the mdev features (API) support by
> >> + * the device.
> > What kind of 'features' are supposed to go in there? Are these bits,
> > like you defined for VIRTIO_MDEV_F_VERSION_1 above?
>
>
> It's the API or mdev features other than virtio features. It could be
> used by driver to determine the capability of the mdev device. Besides
> _F_VERSION_1, we may add dirty page tracking etc which means we need new
> device ops.
Ok, so that's supposed to be distinct bits that can be or'ed together?
Makes sense, but probably needs some more documentation somewhere.
>
>
> >
> >> + * @get_generation: Get device generaton
> >> + * @mdev: mediated device
> >> + * Returns u32: device generation
> > Is that callback mandatory?
>
>
> I think so, it's hard to emulate that completely in virtio-mdev transport.
IIRC, the generation stuff is not mandatory in the current version of
virtio, as not all transports have that concept.
Generally, are any of the callbacks optional, or are all of them
mandatory? From what I understand, you plan to add new things that
depend on features... would that mean non-mandatory callbacks?
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 5/6] virtio: introduce a mdev based transport
2019-10-17 10:48 ` [PATCH V4 5/6] virtio: introduce a mdev based transport Jason Wang
@ 2019-10-18 14:20 ` Cornelia Huck
2019-10-21 5:59 ` Jason Wang
0 siblings, 1 reply; 27+ messages in thread
From: Cornelia Huck @ 2019-10-18 14:20 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On Thu, 17 Oct 2019 18:48:35 +0800
Jason Wang <jasowang@redhat.com> wrote:
> This patch introduces a new mdev transport for virtio. This is used to
> use kernel virtio driver to drive the mediated device that is capable
> of populating virtqueue directly.
>
> A new virtio-mdev driver will be registered to the mdev bus, when a
> new virtio-mdev device is probed, it will register the device with
> mdev based config ops. This means it is a software transport between
> mdev driver and mdev device. The transport was implemented through
> device specific ops which is a part of mdev_parent_ops now.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/virtio/Kconfig | 7 +
> drivers/virtio/Makefile | 1 +
> drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++
> 3 files changed, 417 insertions(+)
(...)
> +static int virtio_mdev_probe(struct device *dev)
> +{
> + struct mdev_device *mdev = mdev_from_dev(dev);
> + const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
> + struct virtio_mdev_device *vm_dev;
> + int rc;
> +
> + vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL);
> + if (!vm_dev)
> + return -ENOMEM;
> +
> + vm_dev->vdev.dev.parent = dev;
> + vm_dev->vdev.dev.release = virtio_mdev_release_dev;
> + vm_dev->vdev.config = &virtio_mdev_config_ops;
> + vm_dev->mdev = mdev;
> + INIT_LIST_HEAD(&vm_dev->virtqueues);
> + spin_lock_init(&vm_dev->lock);
> +
> + vm_dev->version = ops->get_mdev_features(mdev);
> + if (vm_dev->version != VIRTIO_MDEV_F_VERSION_1) {
> + dev_err(dev, "VIRTIO_MDEV_F_VERSION_1 is mandatory\n");
> + return -ENXIO;
> + }
Hm, so how is that mdev features interface supposed to work? If
VIRTIO_MDEV_F_VERSION_1 is a bit, I would expect this code to test for
its presence, and not for identity.
What will happen if we come up with a version 2? If this is backwards
compatible, will both version 2 and version 1 be set?
> +
> + vm_dev->vdev.id.device = ops->get_device_id(mdev);
> + if (vm_dev->vdev.id.device == 0)
> + return -ENODEV;
> +
> + vm_dev->vdev.id.vendor = ops->get_vendor_id(mdev);
> + rc = register_virtio_device(&vm_dev->vdev);
> + if (rc)
> + put_device(dev);
> + else
> + dev_set_drvdata(dev, vm_dev);
> +
> + return rc;
> +}
(...)
^ permalink raw reply [flat|nested] 27+ messages in thread
* RE: [PATCH V4 1/6] mdev: class id support
2019-10-17 10:48 ` [PATCH V4 1/6] mdev: class id support Jason Wang
@ 2019-10-20 23:25 ` Parav Pandit
0 siblings, 0 replies; 27+ messages in thread
From: Parav Pandit @ 2019-10-20 23:25 UTC (permalink / raw)
To: Jason Wang, kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, Ido Shamay,
eperezma, lulu, christophe.de.dinechin, kevin.tian, stefanha
> -----Original Message-----
> From: kvm-owner@vger.kernel.org <kvm-owner@vger.kernel.org> On Behalf
> Of Jason Wang
> Sent: Thursday, October 17, 2019 5:49 AM
> To: kvm@vger.kernel.org; linux-s390@vger.kernel.org; linux-
> kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; intel-
> gfx@lists.freedesktop.org; intel-gvt-dev@lists.freedesktop.org;
> kwankhede@nvidia.com; alex.williamson@redhat.com; mst@redhat.com;
> tiwei.bie@intel.com
> Cc: virtualization@lists.linux-foundation.org; netdev@vger.kernel.org;
> cohuck@redhat.com; maxime.coquelin@redhat.com;
> cunming.liang@intel.com; zhihong.wang@intel.com;
> rob.miller@broadcom.com; xiao.w.wang@intel.com;
> haotian.wang@sifive.com; zhenyuw@linux.intel.com; zhi.a.wang@intel.com;
> jani.nikula@linux.intel.com; joonas.lahtinen@linux.intel.com;
> rodrigo.vivi@intel.com; airlied@linux.ie; daniel@ffwll.ch;
> farman@linux.ibm.com; pasic@linux.ibm.com; sebott@linux.ibm.com;
> oberpar@linux.ibm.com; heiko.carstens@de.ibm.com; gor@linux.ibm.com;
> borntraeger@de.ibm.com; akrowiak@linux.ibm.com; freude@linux.ibm.com;
> lingshan.zhu@intel.com; Ido Shamay <idos@mellanox.com>;
> eperezma@redhat.com; lulu@redhat.com; Parav Pandit
> <parav@mellanox.com>; christophe.de.dinechin@gmail.com;
> kevin.tian@intel.com; stefanha@redhat.com; Jason Wang
> <jasowang@redhat.com>
> Subject: [PATCH V4 1/6] mdev: class id support
>
> Mdev bus only supports vfio driver right now, so it doesn't implement match
> method. But in the future, we may add drivers other than vfio, the first
> driver could be virtio-mdev. This means we need to add device class id
> support in bus match method to pair the mdev device and mdev driver
> correctly.
>
> So this patch adds id_table to mdev_driver and class_id for mdev device
> with the match method for mdev bus.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> .../driver-api/vfio-mediated-device.rst | 7 +++++-
> drivers/gpu/drm/i915/gvt/kvmgt.c | 1 +
> drivers/s390/cio/vfio_ccw_ops.c | 1 +
> drivers/s390/crypto/vfio_ap_ops.c | 1 +
> drivers/vfio/mdev/mdev_core.c | 18 +++++++++++++++
> drivers/vfio/mdev/mdev_driver.c | 22 +++++++++++++++++++
> drivers/vfio/mdev/mdev_private.h | 1 +
> drivers/vfio/mdev/vfio_mdev.c | 6 +++++
> include/linux/mdev.h | 8 +++++++
> include/linux/mod_devicetable.h | 8 +++++++
> samples/vfio-mdev/mbochs.c | 1 +
> samples/vfio-mdev/mdpy.c | 1 +
> samples/vfio-mdev/mtty.c | 1 +
> 13 files changed, 75 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/driver-api/vfio-mediated-device.rst
> b/Documentation/driver-api/vfio-mediated-device.rst
> index 25eb7d5b834b..f9a78d75a67a 100644
> --- a/Documentation/driver-api/vfio-mediated-device.rst
> +++ b/Documentation/driver-api/vfio-mediated-device.rst
> @@ -102,12 +102,14 @@ structure to represent a mediated device's driver::
> * @probe: called when new device created
> * @remove: called when device removed
> * @driver: device driver structure
> + * @id_table: the ids serviced by this driver
> */
> struct mdev_driver {
> const char *name;
> int (*probe) (struct device *dev);
> void (*remove) (struct device *dev);
> struct device_driver driver;
> + const struct mdev_class_id *id_table;
> };
>
> A mediated bus driver for mdev should use this structure in the function
> calls @@ -165,12 +167,15 @@ 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 in create() callback through::
> +
> + int mdev_set_class(struct mdev_device *mdev, u16 id);
> +
> 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::
>
> extern void mdev_unregister_device(struct device *dev);
>
> -
> Mediated Device Management Interface Through sysfs
> ==================================================
>
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 343d79c1cb7e..6420f0dbd31b 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -678,6 +678,7 @@ static int intel_vgpu_create(struct kobject *kobj,
> struct mdev_device *mdev)
> dev_name(mdev_dev(mdev)));
> ret = 0;
>
> + mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> out:
> return ret;
> }
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> b/drivers/s390/cio/vfio_ccw_ops.c index f0d71ab77c50..cf2c013ae32f 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -129,6 +129,7 @@ static int vfio_ccw_mdev_create(struct kobject *kobj,
> struct mdev_device *mdev)
> private->sch->schid.ssid,
> private->sch->schid.sch_no);
>
> + mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> return 0;
> }
>
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
> b/drivers/s390/crypto/vfio_ap_ops.c
> index 5c0f53c6dde7..07c31070afeb 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -343,6 +343,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj,
> struct mdev_device *mdev)
> list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
> mutex_unlock(&matrix_dev->lock);
>
> + mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> return 0;
> }
>
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index b558d4cfd082..3a9c52d71b4e 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -45,6 +45,16 @@ void mdev_set_drvdata(struct mdev_device *mdev,
> void *data) } EXPORT_SYMBOL(mdev_set_drvdata);
>
> +/* Specify the class for the mdev device, this must be called during
> + * create() callback.
> + */
> +void mdev_set_class(struct mdev_device *mdev, u16 id) {
> + WARN_ON(mdev->class_id);
> + mdev->class_id = id;
> +}
> +EXPORT_SYMBOL(mdev_set_class);
> +
> struct device *mdev_dev(struct mdev_device *mdev) {
> return &mdev->dev;
> @@ -135,6 +145,7 @@ static int mdev_device_remove_cb(struct device
> *dev, void *data)
> * mdev_register_device : Register a device
> * @dev: device structure representing parent device.
> * @ops: Parent device operation structure to be registered.
> + * @id: class id.
> *
> * Add device to list of registered parent devices.
> * Returns a negative value on error, otherwise 0.
> @@ -324,6 +335,13 @@ int mdev_device_create(struct kobject *kobj,
> if (ret)
> goto ops_create_fail;
>
> + if (!mdev->class_id) {
> + ret = -EINVAL;
> + WARN(1, "class id must be specified for device %s\n",
> + dev_name(dev));
> + goto add_fail;
> + }
> +
> ret = device_add(&mdev->dev);
> if (ret)
> goto add_fail;
> diff --git a/drivers/vfio/mdev/mdev_driver.c
> b/drivers/vfio/mdev/mdev_driver.c index 0d3223aee20b..319d886ffaf7
> 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -69,8 +69,30 @@ static int mdev_remove(struct device *dev)
> return 0;
> }
>
> +static int mdev_match(struct device *dev, struct device_driver *drv) {
> + unsigned int i;
> + struct mdev_device *mdev = to_mdev_device(dev);
> + struct mdev_driver *mdrv = to_mdev_driver(drv);
> + const struct mdev_class_id *ids = mdrv->id_table;
> +
> + for (i = 0; ids[i].id; i++)
> + if (ids[i].id == mdev->class_id)
> + return 1;
> + return 0;
> +}
> +
> +static int mdev_uevent(struct device *dev, struct kobj_uevent_env *env)
> +{
> + struct mdev_device *mdev = to_mdev_device(dev);
> +
> + return add_uevent_var(env, "MODALIAS=mdev:c%02X", mdev-
> >class_id); }
> +
> struct bus_type mdev_bus_type = {
> .name = "mdev",
> + .match = mdev_match,
> + .uevent = mdev_uevent,
> .probe = mdev_probe,
> .remove = mdev_remove,
> };
> diff --git a/drivers/vfio/mdev/mdev_private.h
> b/drivers/vfio/mdev/mdev_private.h
> index 7d922950caaf..c65f436c1869 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -33,6 +33,7 @@ struct mdev_device {
> struct kobject *type_kobj;
> struct device *iommu_device;
> bool active;
> + u16 class_id;
> };
>
> #define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
> index 30964a4e0a28..7b24ee9cb8dd 100644
> --- a/drivers/vfio/mdev/vfio_mdev.c
> +++ b/drivers/vfio/mdev/vfio_mdev.c
> @@ -120,10 +120,16 @@ static void vfio_mdev_remove(struct device *dev)
> vfio_del_group_dev(dev);
> }
>
> +static const struct mdev_class_id id_table[] = {
> + { MDEV_CLASS_ID_VFIO },
> + { 0 },
> +};
> +
> static struct mdev_driver vfio_mdev_driver = {
> .name = "vfio_mdev",
> .probe = vfio_mdev_probe,
> .remove = vfio_mdev_remove,
> + .id_table = id_table,
> };
>
> static int __init vfio_mdev_init(void)
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h index
> 0ce30ca78db0..78b69d09eb54 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -118,6 +118,7 @@ struct mdev_type_attribute
> mdev_type_attr_##_name = \
> * @probe: called when new device created
> * @remove: called when device removed
> * @driver: device driver structure
> + * @id_table: the ids serviced by this driver
> *
> **/
> struct mdev_driver {
> @@ -125,6 +126,7 @@ struct mdev_driver {
> int (*probe)(struct device *dev);
> void (*remove)(struct device *dev);
> struct device_driver driver;
> + const struct mdev_class_id *id_table;
> };
>
> #define to_mdev_driver(drv) container_of(drv, struct mdev_driver, driver)
> @@ -132,6 +134,7 @@ struct mdev_driver { void *mdev_get_drvdata(struct
> mdev_device *mdev); void mdev_set_drvdata(struct mdev_device *mdev,
> void *data); const guid_t *mdev_uuid(struct mdev_device *mdev);
> +void mdev_set_class(struct mdev_device *mdev, u16 id);
>
> extern struct bus_type mdev_bus_type;
>
> @@ -145,4 +148,9 @@ struct device *mdev_parent_dev(struct mdev_device
> *mdev); struct device *mdev_dev(struct mdev_device *mdev); struct
> mdev_device *mdev_from_dev(struct device *dev);
>
> +enum {
> + MDEV_CLASS_ID_VFIO = 1,
> + /* New entries must be added here */
> +};
> +
> #endif /* MDEV_H */
> diff --git a/include/linux/mod_devicetable.h
> b/include/linux/mod_devicetable.h index 5714fd35a83c..f32c6e44fb1a
> 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -821,4 +821,12 @@ struct wmi_device_id {
> const void *context;
> };
>
> +/**
> + * struct mdev_class_id - MDEV device class identifier
> + * @id: Used to identify a specific class of device, e.g vfio-mdev device.
> + */
> +struct mdev_class_id {
> + __u16 id;
> +};
> +
> #endif /* LINUX_MOD_DEVICETABLE_H */
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index ac5c8c17b1ff..115bc5074656 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -561,6 +561,7 @@ static int mbochs_create(struct kobject *kobj, struct
> mdev_device *mdev)
> mbochs_reset(mdev);
>
> mbochs_used_mbytes += type->mbytes;
> + mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> return 0;
>
> err_mem:
> diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index
> cc86bf6566e4..665614574d50 100644
> --- a/samples/vfio-mdev/mdpy.c
> +++ b/samples/vfio-mdev/mdpy.c
> @@ -269,6 +269,7 @@ static int mdpy_create(struct kobject *kobj, struct
> mdev_device *mdev)
> mdpy_reset(mdev);
>
> mdpy_count++;
> + mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> return 0;
> }
>
> diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index
> ce84a300a4da..90da12ff7fd9 100644
> --- a/samples/vfio-mdev/mtty.c
> +++ b/samples/vfio-mdev/mtty.c
> @@ -755,6 +755,7 @@ static int mtty_create(struct kobject *kobj, struct
> mdev_device *mdev)
> list_add(&mdev_state->next, &mdev_devices_list);
> mutex_unlock(&mdev_list_lock);
>
> + mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> return 0;
> }
>
> --
> 2.19.1
Reviewed-by: Parav Pandit <parav@mellanox.com>
^ permalink raw reply [flat|nested] 27+ messages in thread
* RE: [PATCH V4 2/6] modpost: add support for mdev class id
2019-10-17 10:48 ` [PATCH V4 2/6] modpost: add support for mdev class id Jason Wang
@ 2019-10-20 23:25 ` Parav Pandit
0 siblings, 0 replies; 27+ messages in thread
From: Parav Pandit @ 2019-10-20 23:25 UTC (permalink / raw)
To: Jason Wang, kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, Ido Shamay,
eperezma, lulu, christophe.de.dinechin, kevin.tian, stefanha
> -----Original Message-----
> From: Jason Wang <jasowang@redhat.com>
> Sent: Thursday, October 17, 2019 5:49 AM
> To: kvm@vger.kernel.org; linux-s390@vger.kernel.org; linux-
> kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; intel-
> gfx@lists.freedesktop.org; intel-gvt-dev@lists.freedesktop.org;
> kwankhede@nvidia.com; alex.williamson@redhat.com; mst@redhat.com;
> tiwei.bie@intel.com
> Cc: virtualization@lists.linux-foundation.org; netdev@vger.kernel.org;
> cohuck@redhat.com; maxime.coquelin@redhat.com;
> cunming.liang@intel.com; zhihong.wang@intel.com;
> rob.miller@broadcom.com; xiao.w.wang@intel.com;
> haotian.wang@sifive.com; zhenyuw@linux.intel.com; zhi.a.wang@intel.com;
> jani.nikula@linux.intel.com; joonas.lahtinen@linux.intel.com;
> rodrigo.vivi@intel.com; airlied@linux.ie; daniel@ffwll.ch;
> farman@linux.ibm.com; pasic@linux.ibm.com; sebott@linux.ibm.com;
> oberpar@linux.ibm.com; heiko.carstens@de.ibm.com; gor@linux.ibm.com;
> borntraeger@de.ibm.com; akrowiak@linux.ibm.com; freude@linux.ibm.com;
> lingshan.zhu@intel.com; Ido Shamay <idos@mellanox.com>;
> eperezma@redhat.com; lulu@redhat.com; Parav Pandit
> <parav@mellanox.com>; christophe.de.dinechin@gmail.com;
> kevin.tian@intel.com; stefanha@redhat.com; Jason Wang
> <jasowang@redhat.com>
> Subject: [PATCH V4 2/6] modpost: add support for mdev class id
>
> Add support to parse mdev class id table.
>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> drivers/vfio/mdev/vfio_mdev.c | 2 ++
> scripts/mod/devicetable-offsets.c | 3 +++
> scripts/mod/file2alias.c | 10 ++++++++++
> 3 files changed, 15 insertions(+)
>
> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
> index 7b24ee9cb8dd..cb701cd646f0 100644
> --- a/drivers/vfio/mdev/vfio_mdev.c
> +++ b/drivers/vfio/mdev/vfio_mdev.c
> @@ -125,6 +125,8 @@ static const struct mdev_class_id id_table[] = {
> { 0 },
> };
>
> +MODULE_DEVICE_TABLE(mdev, id_table);
> +
> static struct mdev_driver vfio_mdev_driver = {
> .name = "vfio_mdev",
> .probe = vfio_mdev_probe,
> diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-
> offsets.c
> index 054405b90ba4..6cbb1062488a 100644
> --- a/scripts/mod/devicetable-offsets.c
> +++ b/scripts/mod/devicetable-offsets.c
> @@ -231,5 +231,8 @@ int main(void)
> DEVID(wmi_device_id);
> DEVID_FIELD(wmi_device_id, guid_string);
>
> + DEVID(mdev_class_id);
> + DEVID_FIELD(mdev_class_id, id);
> +
> return 0;
> }
> diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index
> c91eba751804..d365dfe7c718 100644
> --- a/scripts/mod/file2alias.c
> +++ b/scripts/mod/file2alias.c
> @@ -1335,6 +1335,15 @@ static int do_wmi_entry(const char *filename,
> void *symval, char *alias)
> return 1;
> }
>
> +/* looks like: "mdev:cN" */
> +static int do_mdev_entry(const char *filename, void *symval, char
> +*alias) {
> + DEF_FIELD(symval, mdev_class_id, id);
> +
> + sprintf(alias, "mdev:c%02X", id);
> + return 1;
> +}
> +
> /* Does namelen bytes of name exactly match the symbol? */ static bool
> sym_is(const char *name, unsigned namelen, const char *symbol) { @@ -
> 1407,6 +1416,7 @@ static const struct devtable devtable[] = {
> {"typec", SIZE_typec_device_id, do_typec_entry},
> {"tee", SIZE_tee_client_device_id, do_tee_entry},
> {"wmi", SIZE_wmi_device_id, do_wmi_entry},
> + {"mdev", SIZE_mdev_class_id, do_mdev_entry},
> };
>
> /* Create MODULE_ALIAS() statements.
> --
> 2.19.1
Reviewed-by: Parav Pandit <parav@mellanox.com>
^ permalink raw reply [flat|nested] 27+ messages in thread
* RE: [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-17 10:48 ` [PATCH V4 3/6] mdev: introduce device specific ops Jason Wang
2019-10-17 15:07 ` Cornelia Huck
@ 2019-10-20 23:41 ` Parav Pandit
2019-10-21 6:02 ` Jason Wang
1 sibling, 1 reply; 27+ messages in thread
From: Parav Pandit @ 2019-10-20 23:41 UTC (permalink / raw)
To: Jason Wang, kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, Ido Shamay,
eperezma, lulu, christophe.de.dinechin, kevin.tian, stefanha
> -----Original Message-----
> From: Jason Wang <jasowang@redhat.com>
> Sent: Thursday, October 17, 2019 5:49 AM
> To: kvm@vger.kernel.org; linux-s390@vger.kernel.org; linux-
> kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; intel-
> gfx@lists.freedesktop.org; intel-gvt-dev@lists.freedesktop.org;
> kwankhede@nvidia.com; alex.williamson@redhat.com; mst@redhat.com;
> tiwei.bie@intel.com
> Cc: virtualization@lists.linux-foundation.org; netdev@vger.kernel.org;
> cohuck@redhat.com; maxime.coquelin@redhat.com;
> cunming.liang@intel.com; zhihong.wang@intel.com;
> rob.miller@broadcom.com; xiao.w.wang@intel.com;
> haotian.wang@sifive.com; zhenyuw@linux.intel.com; zhi.a.wang@intel.com;
> jani.nikula@linux.intel.com; joonas.lahtinen@linux.intel.com;
> rodrigo.vivi@intel.com; airlied@linux.ie; daniel@ffwll.ch;
> farman@linux.ibm.com; pasic@linux.ibm.com; sebott@linux.ibm.com;
> oberpar@linux.ibm.com; heiko.carstens@de.ibm.com; gor@linux.ibm.com;
> borntraeger@de.ibm.com; akrowiak@linux.ibm.com; freude@linux.ibm.com;
> lingshan.zhu@intel.com; Ido Shamay <idos@mellanox.com>;
> eperezma@redhat.com; lulu@redhat.com; Parav Pandit
> <parav@mellanox.com>; christophe.de.dinechin@gmail.com;
> kevin.tian@intel.com; stefanha@redhat.com; Jason Wang
> <jasowang@redhat.com>
> Subject: [PATCH V4 3/6] mdev: introduce device specific ops
>
> 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@redhat.com>
> ---
> .../driver-api/vfio-mediated-device.rst | 25 +++++----
> 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 | 18 +++++--
> drivers/vfio/mdev/mdev_private.h | 1 +
> drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
> include/linux/mdev.h | 45 ++++------------
> include/linux/vfio_mdev.h | 52 +++++++++++++++++++
> samples/vfio-mdev/mbochs.c | 20 ++++---
> samples/vfio-mdev/mdpy.c | 20 ++++---
> samples/vfio-mdev/mtty.c | 18 ++++---
> 13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
> --- a/Documentation/driver-api/vfio-mediated-device.rst
> +++ b/Documentation/driver-api/vfio-mediated-device.rst
> @@ -152,11 +152,22 @@ 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:
> -
> -* open: open callback of mediated device
> -* close: close callback of mediated device
> -* ioctl: ioctl callback of mediated device
> +As multiple types of mediated devices may be supported, the device must
> +set up the class id and the device specific callbacks in create()
> +callback. E.g for vfio-mdev device it needs to be done through:
> +
> + int mdev_set_vfio_ops(struct mdev_device *mdev,
> + const struct vfio_mdev_ops *vfio_ops);
> +
> +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device with
> +an mdev driver via its id table. The device specific callbacks
> +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
> +the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
> +uses the following device-specific ops:
> +
> +* 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
> @@ -167,10 +178,6 @@ 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 in create() callback through::
> -
> - int mdev_set_class(struct mdev_device *mdev, u16 id);
> -
> 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::
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 8824f61cd2c0..3d196a023b5e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -17127,6 +17127,7 @@ S: Maintained
> F: Documentation/driver-api/vfio-mediated-device.rst
> F: drivers/vfio/mdev/
> F: include/linux/mdev.h
> +F: include/linux/vfio_mdev.h
> F: samples/vfio-mdev/
>
> VFIO PLATFORM DRIVER
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 6420f0dbd31b..306f934c7857 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -42,6 +42,7 @@
> #include <linux/kvm_host.h>
> #include <linux/vfio.h>
> #include <linux/mdev.h>
> +#include <linux/vfio_mdev.h>
> #include <linux/debugfs.h>
>
> #include <linux/nospec.h>
> @@ -643,6 +644,8 @@ static void kvmgt_put_vfio_device(void *vgpu)
> vfio_device_put(((struct intel_vgpu *)vgpu)->vdev.vfio_device); }
>
> +static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops;
> +
> static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
> {
> struct intel_vgpu *vgpu = NULL;
> @@ -678,7 +681,7 @@ static int intel_vgpu_create(struct kobject *kobj,
> struct mdev_device *mdev)
> dev_name(mdev_dev(mdev)));
> ret = 0;
>
> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> + mdev_set_vfio_ops(mdev, &intel_vfio_vgpu_dev_ops);
> out:
> return ret;
> }
> @@ -1599,20 +1602,21 @@ static const struct attribute_group
> *intel_vgpu_groups[] = {
> NULL,
> };
>
> -static struct mdev_parent_ops intel_vgpu_ops = {
> - .mdev_attr_groups = intel_vgpu_groups,
> - .create = intel_vgpu_create,
> - .remove = intel_vgpu_remove,
> -
> +static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops = {
> .open = intel_vgpu_open,
> .release = intel_vgpu_release,
> -
> .read = intel_vgpu_read,
> .write = intel_vgpu_write,
> .mmap = intel_vgpu_mmap,
> .ioctl = intel_vgpu_ioctl,
> };
>
> +static struct mdev_parent_ops intel_vgpu_ops = {
> + .mdev_attr_groups = intel_vgpu_groups,
> + .create = intel_vgpu_create,
> + .remove = intel_vgpu_remove,
> +};
> +
> static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops) {
> struct attribute **kvm_type_attrs;
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> b/drivers/s390/cio/vfio_ccw_ops.c index cf2c013ae32f..6e606cdb1aa9 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -12,6 +12,7 @@
>
> #include <linux/vfio.h>
> #include <linux/mdev.h>
> +#include <linux/vfio_mdev.h>
> #include <linux/nospec.h>
> #include <linux/slab.h>
>
> @@ -110,6 +111,8 @@ static struct attribute_group *mdev_type_groups[] =
> {
> NULL,
> };
>
> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
> +
> static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device
> *mdev) {
> struct vfio_ccw_private *private =
> @@ -129,7 +132,7 @@ static int vfio_ccw_mdev_create(struct kobject *kobj,
> struct mdev_device *mdev)
> private->sch->schid.ssid,
> private->sch->schid.sch_no);
>
> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
> return 0;
> }
>
> @@ -575,11 +578,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct
> mdev_device *mdev,
> }
> }
>
> -static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
> - .owner = THIS_MODULE,
> - .supported_type_groups = mdev_type_groups,
> - .create = vfio_ccw_mdev_create,
> - .remove = vfio_ccw_mdev_remove,
> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
> .open = vfio_ccw_mdev_open,
> .release = vfio_ccw_mdev_release,
> .read = vfio_ccw_mdev_read,
> @@ -587,6 +586,13 @@ static const struct mdev_parent_ops
> vfio_ccw_mdev_ops = {
> .ioctl = vfio_ccw_mdev_ioctl,
> };
>
> +static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
> + .owner = THIS_MODULE,
> + .supported_type_groups = mdev_type_groups,
> + .create = vfio_ccw_mdev_create,
> + .remove = vfio_ccw_mdev_remove,
> +};
> +
> int vfio_ccw_mdev_reg(struct subchannel *sch) {
> return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops); diff -
> -git a/drivers/s390/crypto/vfio_ap_ops.c
> b/drivers/s390/crypto/vfio_ap_ops.c
> index 07c31070afeb..195c8f4c6f10 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -16,6 +16,7 @@
> #include <linux/bitops.h>
> #include <linux/kvm_host.h>
> #include <linux/module.h>
> +#include <linux/vfio_mdev.h>
> #include <asm/kvm.h>
> #include <asm/zcrypt.h>
>
> @@ -321,6 +322,8 @@ static void vfio_ap_matrix_init(struct ap_config_info
> *info,
> matrix->adm_max = info->apxa ? info->Nd : 15; }
>
> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
> +
> static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device
> *mdev) {
> struct ap_matrix_mdev *matrix_mdev;
> @@ -343,7 +346,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj,
> struct mdev_device *mdev)
> list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
> mutex_unlock(&matrix_dev->lock);
>
> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
> return 0;
> }
>
> @@ -1281,15 +1284,18 @@ static ssize_t vfio_ap_mdev_ioctl(struct
> mdev_device *mdev,
> return ret;
> }
>
> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
> + .open = vfio_ap_mdev_open,
> + .release = vfio_ap_mdev_release,
> + .ioctl = vfio_ap_mdev_ioctl,
> +};
> +
> static const struct mdev_parent_ops vfio_ap_matrix_ops = {
> .owner = THIS_MODULE,
> .supported_type_groups = vfio_ap_mdev_type_groups,
> .mdev_attr_groups = vfio_ap_mdev_attr_groups,
> .create = vfio_ap_mdev_create,
> .remove = vfio_ap_mdev_remove,
> - .open = vfio_ap_mdev_open,
> - .release = vfio_ap_mdev_release,
> - .ioctl = vfio_ap_mdev_ioctl,
> };
>
> int vfio_ap_mdev_register(void)
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index 3a9c52d71b4e..d0f3113c8071 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev,
> void *data) } EXPORT_SYMBOL(mdev_set_drvdata);
>
> -/* Specify the class for the mdev device, this must be called during
> - * create() callback.
> +/* Specify the VFIO device ops for the mdev device, this
> + * must be called during create() callback for VFIO mdev device.
> */
> -void mdev_set_class(struct mdev_device *mdev, u16 id)
I think you should keep the mdev_set_class API and let mdev_set_vfio_ops call it. Even though its two line function.
The reason to avoid a code churn in short time with mlx5_core patch which will only call mdev_set_class(), as it doesn't have any ops yet.
> +void mdev_set_vfio_ops(struct mdev_device *mdev,
> + const struct vfio_mdev_device_ops *vfio_ops)
> {
> WARN_ON(mdev->class_id);
> - mdev->class_id = id;
> + mdev->class_id = MDEV_CLASS_ID_VFIO;
> + mdev->device_ops = vfio_ops;
> }
> -EXPORT_SYMBOL(mdev_set_class);
> +EXPORT_SYMBOL(mdev_set_vfio_ops);
> +
> +const void *mdev_get_dev_ops(struct mdev_device *mdev) {
> + return mdev->device_ops;
> +}
> +EXPORT_SYMBOL(mdev_get_dev_ops);
>
> struct device *mdev_dev(struct mdev_device *mdev) { diff --git
> a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
> index c65f436c1869..b666805f0b1f 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -34,6 +34,7 @@ struct mdev_device {
> struct device *iommu_device;
> bool active;
> u16 class_id;
> + const void *device_ops;
Instead of void *, this should be union vfio_ops and virtio_ops.
> };
>
> #define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
> index cb701cd646f0..6b6b92011436 100644
> --- a/drivers/vfio/mdev/vfio_mdev.c
> +++ b/drivers/vfio/mdev/vfio_mdev.c
> @@ -14,6 +14,7 @@
> #include <linux/slab.h>
> #include <linux/vfio.h>
> #include <linux/mdev.h>
> +#include <linux/vfio_mdev.h>
>
> #include "mdev_private.h"
>
> @@ -24,16 +25,16 @@
> static int vfio_mdev_open(void *device_data) {
> struct mdev_device *mdev = device_data;
> - struct mdev_parent *parent = mdev->parent;
> + const struct vfio_mdev_device_ops *ops =
> mdev_get_dev_ops(mdev);
> int ret;
>
> - if (unlikely(!parent->ops->open))
> + if (unlikely(!ops->open))
> return -EINVAL;
>
> if (!try_module_get(THIS_MODULE))
> return -ENODEV;
>
> - ret = parent->ops->open(mdev);
> + ret = ops->open(mdev);
> if (ret)
> module_put(THIS_MODULE);
>
> @@ -43,10 +44,10 @@ static int vfio_mdev_open(void *device_data) static
> void vfio_mdev_release(void *device_data) {
> struct mdev_device *mdev = device_data;
> - struct mdev_parent *parent = mdev->parent;
> + const struct vfio_mdev_device_ops *ops =
> mdev_get_dev_ops(mdev);
>
> - if (likely(parent->ops->release))
> - parent->ops->release(mdev);
> + if (likely(ops->release))
> + ops->release(mdev);
>
> module_put(THIS_MODULE);
> }
> @@ -55,47 +56,47 @@ static long vfio_mdev_unlocked_ioctl(void
> *device_data,
> unsigned int cmd, unsigned long arg) {
> struct mdev_device *mdev = device_data;
> - struct mdev_parent *parent = mdev->parent;
> + const struct vfio_mdev_device_ops *ops =
> mdev_get_dev_ops(mdev);
>
> - if (unlikely(!parent->ops->ioctl))
> + if (unlikely(!ops->ioctl))
> return -EINVAL;
>
> - return parent->ops->ioctl(mdev, cmd, arg);
> + return ops->ioctl(mdev, cmd, arg);
> }
>
> static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
> size_t count, loff_t *ppos)
> {
> struct mdev_device *mdev = device_data;
> - struct mdev_parent *parent = mdev->parent;
> + const struct vfio_mdev_device_ops *ops =
> mdev_get_dev_ops(mdev);
>
> - if (unlikely(!parent->ops->read))
> + if (unlikely(!ops->read))
> return -EINVAL;
>
> - return parent->ops->read(mdev, buf, count, ppos);
> + return ops->read(mdev, buf, count, ppos);
> }
>
> static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
> size_t count, loff_t *ppos)
> {
> struct mdev_device *mdev = device_data;
> - struct mdev_parent *parent = mdev->parent;
> + const struct vfio_mdev_device_ops *ops =
> mdev_get_dev_ops(mdev);
>
> - if (unlikely(!parent->ops->write))
> + if (unlikely(!ops->write))
> return -EINVAL;
>
> - return parent->ops->write(mdev, buf, count, ppos);
> + return ops->write(mdev, buf, count, ppos);
> }
>
> static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
> {
> struct mdev_device *mdev = device_data;
> - struct mdev_parent *parent = mdev->parent;
> + const struct vfio_mdev_device_ops *ops =
> mdev_get_dev_ops(mdev);
>
> - if (unlikely(!parent->ops->mmap))
> + if (unlikely(!ops->mmap))
> return -EINVAL;
>
> - return parent->ops->mmap(mdev, vma);
> + return ops->mmap(mdev, vma);
> }
>
> static const struct vfio_device_ops vfio_mdev_dev_ops = { diff --git
> a/include/linux/mdev.h b/include/linux/mdev.h index
> 78b69d09eb54..3d29e09e20c9 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -10,7 +10,13 @@
> #ifndef MDEV_H
> #define MDEV_H
>
> +#include <linux/types.h>
> +#include <linux/device.h>
> +#include <linux/mdev.h>
> +#include <uapi/linux/uuid.h>
> +
> struct mdev_device;
> +struct vfio_mdev_device_ops;
>
> /*
> * Called by the parent device driver to set the device which represents @@
> -48,30 +54,7 @@ struct device *mdev_get_iommu_device(struct device
> *dev);
> * @mdev: mdev_device device structure which is being
> * destroyed
> * Returns integer: success (0) or error (< 0)
> - * @open: Open mediated device.
> - * @mdev: mediated device.
> - * Returns integer: success (0) or error (< 0)
> - * @release: release mediated device
> - * @mdev: mediated device.
> - * @read: Read emulation callback
> - * @mdev: mediated device structure
> - * @buf: read buffer
> - * @count: number of bytes to read
> - * @ppos: address.
> - * Retuns number on bytes read on success or error.
> - * @write: Write emulation callback
> - * @mdev: mediated device structure
> - * @buf: write buffer
> - * @count: number of bytes to be written
> - * @ppos: address.
> - * Retuns number on bytes written on success or error.
> - * @ioctl: IOCTL callback
> - * @mdev: mediated device structure
> - * @cmd: ioctl command
> - * @arg: arguments to ioctl
> - * @mmap: mmap callback
> - * @mdev: mediated device structure
> - * @vma: vma structure
> + *
> * Parent device that support mediated device should be registered with
> mdev
> * module with mdev_parent_ops structure.
> **/
> @@ -83,15 +66,6 @@ struct mdev_parent_ops {
>
> int (*create)(struct kobject *kobj, struct mdev_device *mdev);
> int (*remove)(struct mdev_device *mdev);
> - int (*open)(struct mdev_device *mdev);
> - void (*release)(struct mdev_device *mdev);
> - ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
> - size_t count, loff_t *ppos);
> - ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
> - size_t count, loff_t *ppos);
> - long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
> - unsigned long arg);
> - int (*mmap)(struct mdev_device *mdev, struct vm_area_struct
> *vma);
> };
>
> /* interface for exporting mdev supported type attributes */ @@ -133,8
> +107,11 @@ struct mdev_driver {
>
> void *mdev_get_drvdata(struct mdev_device *mdev); void
> mdev_set_drvdata(struct mdev_device *mdev, void *data);
> +
Unrelated line change for this patch. Please remove.
> const guid_t *mdev_uuid(struct mdev_device *mdev); -void
> mdev_set_class(struct mdev_device *mdev, u16 id);
> +void mdev_set_vfio_ops(struct mdev_device *mdev,
> + const struct vfio_mdev_device_ops *vfio_ops); const
> void
> +*mdev_get_dev_ops(struct mdev_device *mdev);
>
Since you have the set_vfio_ops, its better to have get_vfio_ops() and similarly get_virtio_ops.
> extern struct bus_type mdev_bus_type;
>
> diff --git a/include/linux/vfio_mdev.h b/include/linux/vfio_mdev.h new file
> mode 100644 index 000000000000..3907c5371c2b
> --- /dev/null
> +++ b/include/linux/vfio_mdev.h
This file name is confusing.
vfio_mdev_ops.h is more accurate name of what it intends to achieve.
If you see this file expanding scope beyond ops, this file name looks fine.
> @@ -0,0 +1,52 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * VFIO Mediated device definition
> + */
> +
> +#ifndef VFIO_MDEV_H
> +#define VFIO_MDEV_H
> +
> +#include <linux/mdev.h>
> +
> +/**
> + * struct vfio_mdev_device_ops - Structure to be registered for each
> + * mdev device to register the device to vfio-mdev module.
> + *
> + * @open: Open mediated device.
> + * @mdev: mediated device.
> + * Returns integer: success (0) or error (< 0)
> + * @release: release mediated device
> + * @mdev: mediated device.
> + * @read: Read emulation callback
> + * @mdev: mediated device structure
> + * @buf: read buffer
> + * @count: number of bytes to read
> + * @ppos: address.
> + * Retuns number on bytes read on success or error.
> + * @write: Write emulation callback
> + * @mdev: mediated device structure
> + * @buf: write buffer
> + * @count: number of bytes to be written
> + * @ppos: address.
> + * Retuns number on bytes written on success or error.
> + * @ioctl: IOCTL callback
> + * @mdev: mediated device structure
> + * @cmd: ioctl command
> + * @arg: arguments to ioctl
> + * @mmap: mmap callback
> + * @mdev: mediated device structure
> + * @vma: vma structure
> + */
> +struct vfio_mdev_device_ops {
> + int (*open)(struct mdev_device *mdev);
> + void (*release)(struct mdev_device *mdev);
> + ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
> + size_t count, loff_t *ppos);
> + ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
> + size_t count, loff_t *ppos);
> + long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
> + unsigned long arg);
> + int (*mmap)(struct mdev_device *mdev, struct vm_area_struct
> *vma);
> +};
> +
> +#endif
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index 115bc5074656..37abdf1b27a8 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -30,6 +30,7 @@
> #include <linux/iommu.h>
> #include <linux/sysfs.h>
> #include <linux/mdev.h>
> +#include <linux/vfio_mdev.h>
> #include <linux/pci.h>
> #include <linux/dma-buf.h>
> #include <linux/highmem.h>
> @@ -516,6 +517,8 @@ static int mbochs_reset(struct mdev_device *mdev)
> return 0;
> }
>
> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
> +
> static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev) {
> const struct mbochs_type *type = mbochs_find_type(kobj); @@ -
> 561,7 +564,7 @@ static int mbochs_create(struct kobject *kobj, struct
> mdev_device *mdev)
> mbochs_reset(mdev);
>
> mbochs_used_mbytes += type->mbytes;
> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
> return 0;
>
> err_mem:
> @@ -1419,12 +1422,7 @@ static struct attribute_group
> *mdev_type_groups[] = {
> NULL,
> };
>
> -static const struct mdev_parent_ops mdev_fops = {
> - .owner = THIS_MODULE,
> - .mdev_attr_groups = mdev_dev_groups,
> - .supported_type_groups = mdev_type_groups,
> - .create = mbochs_create,
> - .remove = mbochs_remove,
> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
> .open = mbochs_open,
> .release = mbochs_close,
> .read = mbochs_read,
> @@ -1433,6 +1431,14 @@ static const struct mdev_parent_ops mdev_fops =
> {
> .mmap = mbochs_mmap,
> };
>
> +static const struct mdev_parent_ops mdev_fops = {
> + .owner = THIS_MODULE,
> + .mdev_attr_groups = mdev_dev_groups,
> + .supported_type_groups = mdev_type_groups,
> + .create = mbochs_create,
> + .remove = mbochs_remove,
> +};
> +
> static const struct file_operations vd_fops = {
> .owner = THIS_MODULE,
> };
> diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index
> 665614574d50..f21c795c40e4 100644
> --- a/samples/vfio-mdev/mdpy.c
> +++ b/samples/vfio-mdev/mdpy.c
> @@ -26,6 +26,7 @@
> #include <linux/iommu.h>
> #include <linux/sysfs.h>
> #include <linux/mdev.h>
> +#include <linux/vfio_mdev.h>
> #include <linux/pci.h>
> #include <drm/drm_fourcc.h>
> #include "mdpy-defs.h"
> @@ -226,6 +227,8 @@ static int mdpy_reset(struct mdev_device *mdev)
> return 0;
> }
>
> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
> +
> static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev) {
> const struct mdpy_type *type = mdpy_find_type(kobj); @@ -269,7
> +272,7 @@ static int mdpy_create(struct kobject *kobj, struct mdev_device
> *mdev)
> mdpy_reset(mdev);
>
> mdpy_count++;
> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
> return 0;
> }
>
> @@ -726,12 +729,7 @@ static struct attribute_group *mdev_type_groups[]
> = {
> NULL,
> };
>
> -static const struct mdev_parent_ops mdev_fops = {
> - .owner = THIS_MODULE,
> - .mdev_attr_groups = mdev_dev_groups,
> - .supported_type_groups = mdev_type_groups,
> - .create = mdpy_create,
> - .remove = mdpy_remove,
> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
> .open = mdpy_open,
> .release = mdpy_close,
> .read = mdpy_read,
> @@ -740,6 +738,14 @@ static const struct mdev_parent_ops mdev_fops = {
> .mmap = mdpy_mmap,
> };
>
> +static const struct mdev_parent_ops mdev_fops = {
> + .owner = THIS_MODULE,
> + .mdev_attr_groups = mdev_dev_groups,
> + .supported_type_groups = mdev_type_groups,
> + .create = mdpy_create,
> + .remove = mdpy_remove,
> +};
> +
> static const struct file_operations vd_fops = {
> .owner = THIS_MODULE,
> };
> diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index
> 90da12ff7fd9..b829f33b98f5 100644
> --- a/samples/vfio-mdev/mtty.c
> +++ b/samples/vfio-mdev/mtty.c
> @@ -27,6 +27,7 @@
> #include <linux/ctype.h>
> #include <linux/file.h>
> #include <linux/mdev.h>
> +#include <linux/vfio_mdev.h>
> #include <linux/pci.h>
> #include <linux/serial.h>
> #include <uapi/linux/serial_reg.h>
> @@ -708,6 +709,8 @@ static ssize_t mdev_access(struct mdev_device
> *mdev, u8 *buf, size_t count,
> return ret;
> }
>
> +static const struct vfio_mdev_device_ops vfio_dev_ops;
> +
> static int mtty_create(struct kobject *kobj, struct mdev_device *mdev) {
> struct mdev_state *mdev_state;
> @@ -755,7 +758,7 @@ static int mtty_create(struct kobject *kobj, struct
> mdev_device *mdev)
> list_add(&mdev_state->next, &mdev_devices_list);
> mutex_unlock(&mdev_list_lock);
>
> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
> + mdev_set_vfio_ops(mdev, &vfio_dev_ops);
> return 0;
> }
>
> @@ -1388,6 +1391,14 @@ static struct attribute_group
> *mdev_type_groups[] = {
> NULL,
> };
>
> +static const struct vfio_mdev_device_ops vfio_dev_ops = {
> + .open = mtty_open,
> + .release = mtty_close,
> + .read = mtty_read,
> + .write = mtty_write,
> + .ioctl = mtty_ioctl,
> +};
> +
Since hunk shows that vfio_dev_ops added new here, it is better to drop the extra white space mixed with tab alignment.
Just have single white space like below.
.open = mtty_open,
.release = mtty_close,
.read = mtty_read,
.write = mtty_write,
.ioctl = mtty_ioctl
> static const struct mdev_parent_ops mdev_fops = {
> .owner = THIS_MODULE,
> .dev_attr_groups = mtty_dev_groups,
> @@ -1395,11 +1406,6 @@ static const struct mdev_parent_ops mdev_fops =
> {
> .supported_type_groups = mdev_type_groups,
> .create = mtty_create,
> .remove = mtty_remove,
> - .open = mtty_open,
> - .release = mtty_close,
> - .read = mtty_read,
> - .write = mtty_write,
> - .ioctl = mtty_ioctl,
> };
>
> static void mtty_device_release(struct device *dev)
> --
> 2.19.1
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 4/6] mdev: introduce virtio device and its device ops
2019-10-18 13:30 ` Cornelia Huck
@ 2019-10-21 5:36 ` Jason Wang
0 siblings, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-21 5:36 UTC (permalink / raw)
To: Cornelia Huck
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/18 下午9:30, Cornelia Huck wrote:
> On Fri, 18 Oct 2019 18:55:02 +0800
> Jason Wang <jasowang@redhat.com> wrote:
>
>> On 2019/10/18 下午5:46, Cornelia Huck wrote:
>>> On Thu, 17 Oct 2019 18:48:34 +0800
>>> Jason Wang <jasowang@redhat.com> wrote:
>>>> + * @get_vendor_id: Get virtio vendor id
>>>> + * @mdev: mediated device
>>>> + * Returns u32: virtio vendor id
>>> How is the vendor id defined? As for normal virtio-pci devices?
>>
>> The vendor that provides this device. So something like this
>>
>> I notice that MMIO also had this so it looks to me it's not pci specific.
> Ok. Would be good to specify this more explicitly.
Ok.
>
>>
>>>
>>>> + * @get_status: Get the device status
>>>> + * @mdev: mediated device
>>>> + * Returns u8: virtio device status
>>>> + * @set_status: Set the device status
>>>> + * @mdev: mediated device
>>>> + * @status: virtio device status
>>>> + * @get_config: Read from device specific configuration space
>>>> + * @mdev: mediated device
>>>> + * @offset: offset from the beginning of
>>>> + * configuration space
>>>> + * @buf: buffer used to read to
>>>> + * @len: the length to read from
>>>> + * configration space
>>>> + * @set_config: Write to device specific configuration space
>>>> + * @mdev: mediated device
>>>> + * @offset: offset from the beginning of
>>>> + * configuration space
>>>> + * @buf: buffer used to write from
>>>> + * @len: the length to write to
>>>> + * configration space
>>>> + * @get_mdev_features: Get the feature of virtio mdev device
>>>> + * @mdev: mediated device
>>>> + * Returns the mdev features (API) support by
>>>> + * the device.
>>> What kind of 'features' are supposed to go in there? Are these bits,
>>> like you defined for VIRTIO_MDEV_F_VERSION_1 above?
>>
>> It's the API or mdev features other than virtio features. It could be
>> used by driver to determine the capability of the mdev device. Besides
>> _F_VERSION_1, we may add dirty page tracking etc which means we need new
>> device ops.
> Ok, so that's supposed to be distinct bits that can be or'ed together?
Yes.
> Makes sense, but probably needs some more documentation somewhere.
Let me add some doc above this helper.
>
>>
>>>
>>>> + * @get_generation: Get device generaton
>>>> + * @mdev: mediated device
>>>> + * Returns u32: device generation
>>> Is that callback mandatory?
>>
>> I think so, it's hard to emulate that completely in virtio-mdev transport.
> IIRC, the generation stuff is not mandatory in the current version of
> virtio, as not all transports have that concept.
It looks to me we can have workaround as what has been done by virtio.c.
Return 0 if this helper is not provided.
>
> Generally, are any of the callbacks optional, or are all of them
> mandatory? From what I understand, you plan to add new things that
> depend on features... would that mean non-mandatory callbacks?
Yes, not all of them were mandatory, I will explicit explain which are
mandatory and which are not.
Thanks
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 5/6] virtio: introduce a mdev based transport
2019-10-18 14:20 ` Cornelia Huck
@ 2019-10-21 5:59 ` Jason Wang
2019-10-21 9:36 ` Cornelia Huck
0 siblings, 1 reply; 27+ messages in thread
From: Jason Wang @ 2019-10-21 5:59 UTC (permalink / raw)
To: Cornelia Huck
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/18 下午10:20, Cornelia Huck wrote:
> On Thu, 17 Oct 2019 18:48:35 +0800
> Jason Wang <jasowang@redhat.com> wrote:
>
>> This patch introduces a new mdev transport for virtio. This is used to
>> use kernel virtio driver to drive the mediated device that is capable
>> of populating virtqueue directly.
>>
>> A new virtio-mdev driver will be registered to the mdev bus, when a
>> new virtio-mdev device is probed, it will register the device with
>> mdev based config ops. This means it is a software transport between
>> mdev driver and mdev device. The transport was implemented through
>> device specific ops which is a part of mdev_parent_ops now.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>> drivers/virtio/Kconfig | 7 +
>> drivers/virtio/Makefile | 1 +
>> drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++
>> 3 files changed, 417 insertions(+)
> (...)
>
>> +static int virtio_mdev_probe(struct device *dev)
>> +{
>> + struct mdev_device *mdev = mdev_from_dev(dev);
>> + const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
>> + struct virtio_mdev_device *vm_dev;
>> + int rc;
>> +
>> + vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL);
>> + if (!vm_dev)
>> + return -ENOMEM;
>> +
>> + vm_dev->vdev.dev.parent = dev;
>> + vm_dev->vdev.dev.release = virtio_mdev_release_dev;
>> + vm_dev->vdev.config = &virtio_mdev_config_ops;
>> + vm_dev->mdev = mdev;
>> + INIT_LIST_HEAD(&vm_dev->virtqueues);
>> + spin_lock_init(&vm_dev->lock);
>> +
>> + vm_dev->version = ops->get_mdev_features(mdev);
>> + if (vm_dev->version != VIRTIO_MDEV_F_VERSION_1) {
>> + dev_err(dev, "VIRTIO_MDEV_F_VERSION_1 is mandatory\n");
>> + return -ENXIO;
>> + }
> Hm, so how is that mdev features interface supposed to work? If
> VIRTIO_MDEV_F_VERSION_1 is a bit, I would expect this code to test for
> its presence, and not for identity.
This should be used by driver to detect the which sets of functions and
their semantics that could be provided by the device. E.g when driver
support both version 2 and version 1 but device only support version 1,
driver can switch to use version 1. Btw, Is there a easy way for to test
its presence or do you mean doing sanity testing on existence of the
mandatory ops that provided by the device?
>
> What will happen if we come up with a version 2? If this is backwards
> compatible, will both version 2 and version 1 be set?
Yes, I think so, and version 2 should be considered as some extensions
of version 1. If it's completely, it should use a new class id.
Thanks
>
>> +
>> + vm_dev->vdev.id.device = ops->get_device_id(mdev);
>> + if (vm_dev->vdev.id.device == 0)
>> + return -ENODEV;
>> +
>> + vm_dev->vdev.id.vendor = ops->get_vendor_id(mdev);
>> + rc = register_virtio_device(&vm_dev->vdev);
>> + if (rc)
>> + put_device(dev);
>> + else
>> + dev_set_drvdata(dev, vm_dev);
>> +
>> + return rc;
>> +}
> (...)
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 3/6] mdev: introduce device specific ops
2019-10-20 23:41 ` Parav Pandit
@ 2019-10-21 6:02 ` Jason Wang
0 siblings, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-21 6:02 UTC (permalink / raw)
To: Parav Pandit, kvm, linux-s390, linux-kernel, dri-devel,
intel-gfx, intel-gvt-dev, kwankhede, alex.williamson, mst,
tiwei.bie
Cc: virtualization, netdev, cohuck, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, Ido Shamay,
eperezma, lulu, christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/21 上午7:41, Parav Pandit wrote:
>
>> -----Original Message-----
>> From: Jason Wang <jasowang@redhat.com>
>> Sent: Thursday, October 17, 2019 5:49 AM
>> To: kvm@vger.kernel.org; linux-s390@vger.kernel.org; linux-
>> kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; intel-
>> gfx@lists.freedesktop.org; intel-gvt-dev@lists.freedesktop.org;
>> kwankhede@nvidia.com; alex.williamson@redhat.com; mst@redhat.com;
>> tiwei.bie@intel.com
>> Cc: virtualization@lists.linux-foundation.org; netdev@vger.kernel.org;
>> cohuck@redhat.com; maxime.coquelin@redhat.com;
>> cunming.liang@intel.com; zhihong.wang@intel.com;
>> rob.miller@broadcom.com; xiao.w.wang@intel.com;
>> haotian.wang@sifive.com; zhenyuw@linux.intel.com; zhi.a.wang@intel.com;
>> jani.nikula@linux.intel.com; joonas.lahtinen@linux.intel.com;
>> rodrigo.vivi@intel.com; airlied@linux.ie; daniel@ffwll.ch;
>> farman@linux.ibm.com; pasic@linux.ibm.com; sebott@linux.ibm.com;
>> oberpar@linux.ibm.com; heiko.carstens@de.ibm.com; gor@linux.ibm.com;
>> borntraeger@de.ibm.com; akrowiak@linux.ibm.com; freude@linux.ibm.com;
>> lingshan.zhu@intel.com; Ido Shamay <idos@mellanox.com>;
>> eperezma@redhat.com; lulu@redhat.com; Parav Pandit
>> <parav@mellanox.com>; christophe.de.dinechin@gmail.com;
>> kevin.tian@intel.com; stefanha@redhat.com; Jason Wang
>> <jasowang@redhat.com>
>> Subject: [PATCH V4 3/6] mdev: introduce device specific ops
>>
>> 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@redhat.com>
>> ---
>> .../driver-api/vfio-mediated-device.rst | 25 +++++----
>> 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 | 18 +++++--
>> drivers/vfio/mdev/mdev_private.h | 1 +
>> drivers/vfio/mdev/vfio_mdev.c | 37 ++++++-------
>> include/linux/mdev.h | 45 ++++------------
>> include/linux/vfio_mdev.h | 52 +++++++++++++++++++
>> samples/vfio-mdev/mbochs.c | 20 ++++---
>> samples/vfio-mdev/mdpy.c | 20 ++++---
>> samples/vfio-mdev/mtty.c | 18 ++++---
>> 13 files changed, 184 insertions(+), 103 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 f9a78d75a67a..0cca84d19603 100644
>> --- a/Documentation/driver-api/vfio-mediated-device.rst
>> +++ b/Documentation/driver-api/vfio-mediated-device.rst
>> @@ -152,11 +152,22 @@ 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:
>> -
>> -* open: open callback of mediated device
>> -* close: close callback of mediated device
>> -* ioctl: ioctl callback of mediated device
>> +As multiple types of mediated devices may be supported, the device must
>> +set up the class id and the device specific callbacks in create()
>> +callback. E.g for vfio-mdev device it needs to be done through:
>> +
>> + int mdev_set_vfio_ops(struct mdev_device *mdev,
>> + const struct vfio_mdev_ops *vfio_ops);
>> +
>> +The class id (set to MDEV_CLASS_ID_VFIO) is used to match a device with
>> +an mdev driver via its id table. The device specific callbacks
>> +(specified in *ops) are obtainable via mdev_get_dev_ops() (for use by
>> +the mdev bus driver). A vfio-mdev device (class id MDEV_CLASS_ID_VFIO)
>> +uses the following device-specific ops:
>> +
>> +* 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
>> @@ -167,10 +178,6 @@ 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 in create() callback through::
>> -
>> - int mdev_set_class(struct mdev_device *mdev, u16 id);
>> -
>> 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::
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 8824f61cd2c0..3d196a023b5e 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -17127,6 +17127,7 @@ S: Maintained
>> F: Documentation/driver-api/vfio-mediated-device.rst
>> F: drivers/vfio/mdev/
>> F: include/linux/mdev.h
>> +F: include/linux/vfio_mdev.h
>> F: samples/vfio-mdev/
>>
>> VFIO PLATFORM DRIVER
>> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
>> b/drivers/gpu/drm/i915/gvt/kvmgt.c
>> index 6420f0dbd31b..306f934c7857 100644
>> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
>> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
>> @@ -42,6 +42,7 @@
>> #include <linux/kvm_host.h>
>> #include <linux/vfio.h>
>> #include <linux/mdev.h>
>> +#include <linux/vfio_mdev.h>
>> #include <linux/debugfs.h>
>>
>> #include <linux/nospec.h>
>> @@ -643,6 +644,8 @@ static void kvmgt_put_vfio_device(void *vgpu)
>> vfio_device_put(((struct intel_vgpu *)vgpu)->vdev.vfio_device); }
>>
>> +static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops;
>> +
>> static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mdev)
>> {
>> struct intel_vgpu *vgpu = NULL;
>> @@ -678,7 +681,7 @@ static int intel_vgpu_create(struct kobject *kobj,
>> struct mdev_device *mdev)
>> dev_name(mdev_dev(mdev)));
>> ret = 0;
>>
>> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
>> + mdev_set_vfio_ops(mdev, &intel_vfio_vgpu_dev_ops);
>> out:
>> return ret;
>> }
>> @@ -1599,20 +1602,21 @@ static const struct attribute_group
>> *intel_vgpu_groups[] = {
>> NULL,
>> };
>>
>> -static struct mdev_parent_ops intel_vgpu_ops = {
>> - .mdev_attr_groups = intel_vgpu_groups,
>> - .create = intel_vgpu_create,
>> - .remove = intel_vgpu_remove,
>> -
>> +static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops = {
>> .open = intel_vgpu_open,
>> .release = intel_vgpu_release,
>> -
>> .read = intel_vgpu_read,
>> .write = intel_vgpu_write,
>> .mmap = intel_vgpu_mmap,
>> .ioctl = intel_vgpu_ioctl,
>> };
>>
>> +static struct mdev_parent_ops intel_vgpu_ops = {
>> + .mdev_attr_groups = intel_vgpu_groups,
>> + .create = intel_vgpu_create,
>> + .remove = intel_vgpu_remove,
>> +};
>> +
>> static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops) {
>> struct attribute **kvm_type_attrs;
>> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
>> b/drivers/s390/cio/vfio_ccw_ops.c index cf2c013ae32f..6e606cdb1aa9 100644
>> --- a/drivers/s390/cio/vfio_ccw_ops.c
>> +++ b/drivers/s390/cio/vfio_ccw_ops.c
>> @@ -12,6 +12,7 @@
>>
>> #include <linux/vfio.h>
>> #include <linux/mdev.h>
>> +#include <linux/vfio_mdev.h>
>> #include <linux/nospec.h>
>> #include <linux/slab.h>
>>
>> @@ -110,6 +111,8 @@ static struct attribute_group *mdev_type_groups[] =
>> {
>> NULL,
>> };
>>
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
>> +
>> static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device
>> *mdev) {
>> struct vfio_ccw_private *private =
>> @@ -129,7 +132,7 @@ static int vfio_ccw_mdev_create(struct kobject *kobj,
>> struct mdev_device *mdev)
>> private->sch->schid.ssid,
>> private->sch->schid.sch_no);
>>
>> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
>> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
>> return 0;
>> }
>>
>> @@ -575,11 +578,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct
>> mdev_device *mdev,
>> }
>> }
>>
>> -static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
>> - .owner = THIS_MODULE,
>> - .supported_type_groups = mdev_type_groups,
>> - .create = vfio_ccw_mdev_create,
>> - .remove = vfio_ccw_mdev_remove,
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
>> .open = vfio_ccw_mdev_open,
>> .release = vfio_ccw_mdev_release,
>> .read = vfio_ccw_mdev_read,
>> @@ -587,6 +586,13 @@ static const struct mdev_parent_ops
>> vfio_ccw_mdev_ops = {
>> .ioctl = vfio_ccw_mdev_ioctl,
>> };
>>
>> +static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
>> + .owner = THIS_MODULE,
>> + .supported_type_groups = mdev_type_groups,
>> + .create = vfio_ccw_mdev_create,
>> + .remove = vfio_ccw_mdev_remove,
>> +};
>> +
>> int vfio_ccw_mdev_reg(struct subchannel *sch) {
>> return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops); diff -
>> -git a/drivers/s390/crypto/vfio_ap_ops.c
>> b/drivers/s390/crypto/vfio_ap_ops.c
>> index 07c31070afeb..195c8f4c6f10 100644
>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>> @@ -16,6 +16,7 @@
>> #include <linux/bitops.h>
>> #include <linux/kvm_host.h>
>> #include <linux/module.h>
>> +#include <linux/vfio_mdev.h>
>> #include <asm/kvm.h>
>> #include <asm/zcrypt.h>
>>
>> @@ -321,6 +322,8 @@ static void vfio_ap_matrix_init(struct ap_config_info
>> *info,
>> matrix->adm_max = info->apxa ? info->Nd : 15; }
>>
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
>> +
>> static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device
>> *mdev) {
>> struct ap_matrix_mdev *matrix_mdev;
>> @@ -343,7 +346,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj,
>> struct mdev_device *mdev)
>> list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
>> mutex_unlock(&matrix_dev->lock);
>>
>> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
>> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
>> return 0;
>> }
>>
>> @@ -1281,15 +1284,18 @@ static ssize_t vfio_ap_mdev_ioctl(struct
>> mdev_device *mdev,
>> return ret;
>> }
>>
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
>> + .open = vfio_ap_mdev_open,
>> + .release = vfio_ap_mdev_release,
>> + .ioctl = vfio_ap_mdev_ioctl,
>> +};
>> +
>> static const struct mdev_parent_ops vfio_ap_matrix_ops = {
>> .owner = THIS_MODULE,
>> .supported_type_groups = vfio_ap_mdev_type_groups,
>> .mdev_attr_groups = vfio_ap_mdev_attr_groups,
>> .create = vfio_ap_mdev_create,
>> .remove = vfio_ap_mdev_remove,
>> - .open = vfio_ap_mdev_open,
>> - .release = vfio_ap_mdev_release,
>> - .ioctl = vfio_ap_mdev_ioctl,
>> };
>>
>> int vfio_ap_mdev_register(void)
>> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
>> index 3a9c52d71b4e..d0f3113c8071 100644
>> --- a/drivers/vfio/mdev/mdev_core.c
>> +++ b/drivers/vfio/mdev/mdev_core.c
>> @@ -45,15 +45,23 @@ void mdev_set_drvdata(struct mdev_device *mdev,
>> void *data) } EXPORT_SYMBOL(mdev_set_drvdata);
>>
>> -/* Specify the class for the mdev device, this must be called during
>> - * create() callback.
>> +/* Specify the VFIO device ops for the mdev device, this
>> + * must be called during create() callback for VFIO mdev device.
>> */
>> -void mdev_set_class(struct mdev_device *mdev, u16 id)
> I think you should keep the mdev_set_class API and let mdev_set_vfio_ops call it. Even though its two line function.
> The reason to avoid a code churn in short time with mlx5_core patch which will only call mdev_set_class(), as it doesn't have any ops yet.
That sounds good, will do.
>> +void mdev_set_vfio_ops(struct mdev_device *mdev,
>> + const struct vfio_mdev_device_ops *vfio_ops)
>> {
>> WARN_ON(mdev->class_id);
>> - mdev->class_id = id;
>> + mdev->class_id = MDEV_CLASS_ID_VFIO;
>> + mdev->device_ops = vfio_ops;
>> }
>> -EXPORT_SYMBOL(mdev_set_class);
>> +EXPORT_SYMBOL(mdev_set_vfio_ops);
>> +
>> +const void *mdev_get_dev_ops(struct mdev_device *mdev) {
>> + return mdev->device_ops;
>> +}
>> +EXPORT_SYMBOL(mdev_get_dev_ops);
>>
>> struct device *mdev_dev(struct mdev_device *mdev) { diff --git
>> a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
>> index c65f436c1869..b666805f0b1f 100644
>> --- a/drivers/vfio/mdev/mdev_private.h
>> +++ b/drivers/vfio/mdev/mdev_private.h
>> @@ -34,6 +34,7 @@ struct mdev_device {
>> struct device *iommu_device;
>> bool active;
>> u16 class_id;
>> + const void *device_ops;
> Instead of void *, this should be union vfio_ops and virtio_ops.
Ok.
>> };
>>
>> #define to_mdev_device(dev) container_of(dev, struct mdev_device, dev)
>> diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
>> index cb701cd646f0..6b6b92011436 100644
>> --- a/drivers/vfio/mdev/vfio_mdev.c
>> +++ b/drivers/vfio/mdev/vfio_mdev.c
>> @@ -14,6 +14,7 @@
>> #include <linux/slab.h>
>> #include <linux/vfio.h>
>> #include <linux/mdev.h>
>> +#include <linux/vfio_mdev.h>
>>
>> #include "mdev_private.h"
>>
>> @@ -24,16 +25,16 @@
>> static int vfio_mdev_open(void *device_data) {
>> struct mdev_device *mdev = device_data;
>> - struct mdev_parent *parent = mdev->parent;
>> + const struct vfio_mdev_device_ops *ops =
>> mdev_get_dev_ops(mdev);
>> int ret;
>>
>> - if (unlikely(!parent->ops->open))
>> + if (unlikely(!ops->open))
>> return -EINVAL;
>>
>> if (!try_module_get(THIS_MODULE))
>> return -ENODEV;
>>
>> - ret = parent->ops->open(mdev);
>> + ret = ops->open(mdev);
>> if (ret)
>> module_put(THIS_MODULE);
>>
>> @@ -43,10 +44,10 @@ static int vfio_mdev_open(void *device_data) static
>> void vfio_mdev_release(void *device_data) {
>> struct mdev_device *mdev = device_data;
>> - struct mdev_parent *parent = mdev->parent;
>> + const struct vfio_mdev_device_ops *ops =
>> mdev_get_dev_ops(mdev);
>>
>> - if (likely(parent->ops->release))
>> - parent->ops->release(mdev);
>> + if (likely(ops->release))
>> + ops->release(mdev);
>>
>> module_put(THIS_MODULE);
>> }
>> @@ -55,47 +56,47 @@ static long vfio_mdev_unlocked_ioctl(void
>> *device_data,
>> unsigned int cmd, unsigned long arg) {
>> struct mdev_device *mdev = device_data;
>> - struct mdev_parent *parent = mdev->parent;
>> + const struct vfio_mdev_device_ops *ops =
>> mdev_get_dev_ops(mdev);
>>
>> - if (unlikely(!parent->ops->ioctl))
>> + if (unlikely(!ops->ioctl))
>> return -EINVAL;
>>
>> - return parent->ops->ioctl(mdev, cmd, arg);
>> + return ops->ioctl(mdev, cmd, arg);
>> }
>>
>> static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
>> size_t count, loff_t *ppos)
>> {
>> struct mdev_device *mdev = device_data;
>> - struct mdev_parent *parent = mdev->parent;
>> + const struct vfio_mdev_device_ops *ops =
>> mdev_get_dev_ops(mdev);
>>
>> - if (unlikely(!parent->ops->read))
>> + if (unlikely(!ops->read))
>> return -EINVAL;
>>
>> - return parent->ops->read(mdev, buf, count, ppos);
>> + return ops->read(mdev, buf, count, ppos);
>> }
>>
>> static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
>> size_t count, loff_t *ppos)
>> {
>> struct mdev_device *mdev = device_data;
>> - struct mdev_parent *parent = mdev->parent;
>> + const struct vfio_mdev_device_ops *ops =
>> mdev_get_dev_ops(mdev);
>>
>> - if (unlikely(!parent->ops->write))
>> + if (unlikely(!ops->write))
>> return -EINVAL;
>>
>> - return parent->ops->write(mdev, buf, count, ppos);
>> + return ops->write(mdev, buf, count, ppos);
>> }
>>
>> static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
>> {
>> struct mdev_device *mdev = device_data;
>> - struct mdev_parent *parent = mdev->parent;
>> + const struct vfio_mdev_device_ops *ops =
>> mdev_get_dev_ops(mdev);
>>
>> - if (unlikely(!parent->ops->mmap))
>> + if (unlikely(!ops->mmap))
>> return -EINVAL;
>>
>> - return parent->ops->mmap(mdev, vma);
>> + return ops->mmap(mdev, vma);
>> }
>>
>> static const struct vfio_device_ops vfio_mdev_dev_ops = { diff --git
>> a/include/linux/mdev.h b/include/linux/mdev.h index
>> 78b69d09eb54..3d29e09e20c9 100644
>> --- a/include/linux/mdev.h
>> +++ b/include/linux/mdev.h
>> @@ -10,7 +10,13 @@
>> #ifndef MDEV_H
>> #define MDEV_H
>>
>> +#include <linux/types.h>
>> +#include <linux/device.h>
>> +#include <linux/mdev.h>
>> +#include <uapi/linux/uuid.h>
>> +
>> struct mdev_device;
>> +struct vfio_mdev_device_ops;
>>
>> /*
>> * Called by the parent device driver to set the device which represents @@
>> -48,30 +54,7 @@ struct device *mdev_get_iommu_device(struct device
>> *dev);
>> * @mdev: mdev_device device structure which is being
>> * destroyed
>> * Returns integer: success (0) or error (< 0)
>> - * @open: Open mediated device.
>> - * @mdev: mediated device.
>> - * Returns integer: success (0) or error (< 0)
>> - * @release: release mediated device
>> - * @mdev: mediated device.
>> - * @read: Read emulation callback
>> - * @mdev: mediated device structure
>> - * @buf: read buffer
>> - * @count: number of bytes to read
>> - * @ppos: address.
>> - * Retuns number on bytes read on success or error.
>> - * @write: Write emulation callback
>> - * @mdev: mediated device structure
>> - * @buf: write buffer
>> - * @count: number of bytes to be written
>> - * @ppos: address.
>> - * Retuns number on bytes written on success or error.
>> - * @ioctl: IOCTL callback
>> - * @mdev: mediated device structure
>> - * @cmd: ioctl command
>> - * @arg: arguments to ioctl
>> - * @mmap: mmap callback
>> - * @mdev: mediated device structure
>> - * @vma: vma structure
>> + *
>> * Parent device that support mediated device should be registered with
>> mdev
>> * module with mdev_parent_ops structure.
>> **/
>> @@ -83,15 +66,6 @@ struct mdev_parent_ops {
>>
>> int (*create)(struct kobject *kobj, struct mdev_device *mdev);
>> int (*remove)(struct mdev_device *mdev);
>> - int (*open)(struct mdev_device *mdev);
>> - void (*release)(struct mdev_device *mdev);
>> - ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
>> - size_t count, loff_t *ppos);
>> - ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
>> - size_t count, loff_t *ppos);
>> - long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
>> - unsigned long arg);
>> - int (*mmap)(struct mdev_device *mdev, struct vm_area_struct
>> *vma);
>> };
>>
>> /* interface for exporting mdev supported type attributes */ @@ -133,8
>> +107,11 @@ struct mdev_driver {
>>
>> void *mdev_get_drvdata(struct mdev_device *mdev); void
>> mdev_set_drvdata(struct mdev_device *mdev, void *data);
>> +
> Unrelated line change for this patch. Please remove.
Sure.
>
>> const guid_t *mdev_uuid(struct mdev_device *mdev); -void
>> mdev_set_class(struct mdev_device *mdev, u16 id);
>> +void mdev_set_vfio_ops(struct mdev_device *mdev,
>> + const struct vfio_mdev_device_ops *vfio_ops); const
>> void
>> +*mdev_get_dev_ops(struct mdev_device *mdev);
>>
> Since you have the set_vfio_ops, its better to have get_vfio_ops() and similarly get_virtio_ops.
Ok.
>
>> extern struct bus_type mdev_bus_type;
>>
>> diff --git a/include/linux/vfio_mdev.h b/include/linux/vfio_mdev.h new file
>> mode 100644 index 000000000000..3907c5371c2b
>> --- /dev/null
>> +++ b/include/linux/vfio_mdev.h
> This file name is confusing.
> vfio_mdev_ops.h is more accurate name of what it intends to achieve.
> If you see this file expanding scope beyond ops, this file name looks fine.
>
>> @@ -0,0 +1,52 @@
>> +/* SPDX-License-Identifier: GPL-2.0-only */
>> +/*
>> + * VFIO Mediated device definition
>> + */
>> +
>> +#ifndef VFIO_MDEV_H
>> +#define VFIO_MDEV_H
>> +
>> +#include <linux/mdev.h>
>> +
>> +/**
>> + * struct vfio_mdev_device_ops - Structure to be registered for each
>> + * mdev device to register the device to vfio-mdev module.
>> + *
>> + * @open: Open mediated device.
>> + * @mdev: mediated device.
>> + * Returns integer: success (0) or error (< 0)
>> + * @release: release mediated device
>> + * @mdev: mediated device.
>> + * @read: Read emulation callback
>> + * @mdev: mediated device structure
>> + * @buf: read buffer
>> + * @count: number of bytes to read
>> + * @ppos: address.
>> + * Retuns number on bytes read on success or error.
>> + * @write: Write emulation callback
>> + * @mdev: mediated device structure
>> + * @buf: write buffer
>> + * @count: number of bytes to be written
>> + * @ppos: address.
>> + * Retuns number on bytes written on success or error.
>> + * @ioctl: IOCTL callback
>> + * @mdev: mediated device structure
>> + * @cmd: ioctl command
>> + * @arg: arguments to ioctl
>> + * @mmap: mmap callback
>> + * @mdev: mediated device structure
>> + * @vma: vma structure
>> + */
>> +struct vfio_mdev_device_ops {
>> + int (*open)(struct mdev_device *mdev);
>> + void (*release)(struct mdev_device *mdev);
>> + ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
>> + size_t count, loff_t *ppos);
>> + ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
>> + size_t count, loff_t *ppos);
>> + long (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
>> + unsigned long arg);
>> + int (*mmap)(struct mdev_device *mdev, struct vm_area_struct
>> *vma);
>> +};
>> +
>> +#endif
>> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
>> index 115bc5074656..37abdf1b27a8 100644
>> --- a/samples/vfio-mdev/mbochs.c
>> +++ b/samples/vfio-mdev/mbochs.c
>> @@ -30,6 +30,7 @@
>> #include <linux/iommu.h>
>> #include <linux/sysfs.h>
>> #include <linux/mdev.h>
>> +#include <linux/vfio_mdev.h>
>> #include <linux/pci.h>
>> #include <linux/dma-buf.h>
>> #include <linux/highmem.h>
>> @@ -516,6 +517,8 @@ static int mbochs_reset(struct mdev_device *mdev)
>> return 0;
>> }
>>
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
>> +
>> static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev) {
>> const struct mbochs_type *type = mbochs_find_type(kobj); @@ -
>> 561,7 +564,7 @@ static int mbochs_create(struct kobject *kobj, struct
>> mdev_device *mdev)
>> mbochs_reset(mdev);
>>
>> mbochs_used_mbytes += type->mbytes;
>> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
>> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
>> return 0;
>>
>> err_mem:
>> @@ -1419,12 +1422,7 @@ static struct attribute_group
>> *mdev_type_groups[] = {
>> NULL,
>> };
>>
>> -static const struct mdev_parent_ops mdev_fops = {
>> - .owner = THIS_MODULE,
>> - .mdev_attr_groups = mdev_dev_groups,
>> - .supported_type_groups = mdev_type_groups,
>> - .create = mbochs_create,
>> - .remove = mbochs_remove,
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
>> .open = mbochs_open,
>> .release = mbochs_close,
>> .read = mbochs_read,
>> @@ -1433,6 +1431,14 @@ static const struct mdev_parent_ops mdev_fops =
>> {
>> .mmap = mbochs_mmap,
>> };
>>
>> +static const struct mdev_parent_ops mdev_fops = {
>> + .owner = THIS_MODULE,
>> + .mdev_attr_groups = mdev_dev_groups,
>> + .supported_type_groups = mdev_type_groups,
>> + .create = mbochs_create,
>> + .remove = mbochs_remove,
>> +};
>> +
>> static const struct file_operations vd_fops = {
>> .owner = THIS_MODULE,
>> };
>> diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c index
>> 665614574d50..f21c795c40e4 100644
>> --- a/samples/vfio-mdev/mdpy.c
>> +++ b/samples/vfio-mdev/mdpy.c
>> @@ -26,6 +26,7 @@
>> #include <linux/iommu.h>
>> #include <linux/sysfs.h>
>> #include <linux/mdev.h>
>> +#include <linux/vfio_mdev.h>
>> #include <linux/pci.h>
>> #include <drm/drm_fourcc.h>
>> #include "mdpy-defs.h"
>> @@ -226,6 +227,8 @@ static int mdpy_reset(struct mdev_device *mdev)
>> return 0;
>> }
>>
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops;
>> +
>> static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev) {
>> const struct mdpy_type *type = mdpy_find_type(kobj); @@ -269,7
>> +272,7 @@ static int mdpy_create(struct kobject *kobj, struct mdev_device
>> *mdev)
>> mdpy_reset(mdev);
>>
>> mdpy_count++;
>> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
>> + mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
>> return 0;
>> }
>>
>> @@ -726,12 +729,7 @@ static struct attribute_group *mdev_type_groups[]
>> = {
>> NULL,
>> };
>>
>> -static const struct mdev_parent_ops mdev_fops = {
>> - .owner = THIS_MODULE,
>> - .mdev_attr_groups = mdev_dev_groups,
>> - .supported_type_groups = mdev_type_groups,
>> - .create = mdpy_create,
>> - .remove = mdpy_remove,
>> +static const struct vfio_mdev_device_ops vfio_mdev_ops = {
>> .open = mdpy_open,
>> .release = mdpy_close,
>> .read = mdpy_read,
>> @@ -740,6 +738,14 @@ static const struct mdev_parent_ops mdev_fops = {
>> .mmap = mdpy_mmap,
>> };
>>
>> +static const struct mdev_parent_ops mdev_fops = {
>> + .owner = THIS_MODULE,
>> + .mdev_attr_groups = mdev_dev_groups,
>> + .supported_type_groups = mdev_type_groups,
>> + .create = mdpy_create,
>> + .remove = mdpy_remove,
>> +};
>> +
>> static const struct file_operations vd_fops = {
>> .owner = THIS_MODULE,
>> };
>> diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c index
>> 90da12ff7fd9..b829f33b98f5 100644
>> --- a/samples/vfio-mdev/mtty.c
>> +++ b/samples/vfio-mdev/mtty.c
>> @@ -27,6 +27,7 @@
>> #include <linux/ctype.h>
>> #include <linux/file.h>
>> #include <linux/mdev.h>
>> +#include <linux/vfio_mdev.h>
>> #include <linux/pci.h>
>> #include <linux/serial.h>
>> #include <uapi/linux/serial_reg.h>
>> @@ -708,6 +709,8 @@ static ssize_t mdev_access(struct mdev_device
>> *mdev, u8 *buf, size_t count,
>> return ret;
>> }
>>
>> +static const struct vfio_mdev_device_ops vfio_dev_ops;
>> +
>> static int mtty_create(struct kobject *kobj, struct mdev_device *mdev) {
>> struct mdev_state *mdev_state;
>> @@ -755,7 +758,7 @@ static int mtty_create(struct kobject *kobj, struct
>> mdev_device *mdev)
>> list_add(&mdev_state->next, &mdev_devices_list);
>> mutex_unlock(&mdev_list_lock);
>>
>> - mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
>> + mdev_set_vfio_ops(mdev, &vfio_dev_ops);
>> return 0;
>> }
>>
>> @@ -1388,6 +1391,14 @@ static struct attribute_group
>> *mdev_type_groups[] = {
>> NULL,
>> };
>>
>> +static const struct vfio_mdev_device_ops vfio_dev_ops = {
>> + .open = mtty_open,
>> + .release = mtty_close,
>> + .read = mtty_read,
>> + .write = mtty_write,
>> + .ioctl = mtty_ioctl,
>> +};
>> +
> Since hunk shows that vfio_dev_ops added new here, it is better to drop the extra white space mixed with tab alignment.
> Just have single white space like below.
>
> .open = mtty_open,
> .release = mtty_close,
> .read = mtty_read,
> .write = mtty_write,
> .ioctl = mtty_ioctl
Will do.
Thanks
>
>> static const struct mdev_parent_ops mdev_fops = {
>> .owner = THIS_MODULE,
>> .dev_attr_groups = mtty_dev_groups,
>> @@ -1395,11 +1406,6 @@ static const struct mdev_parent_ops mdev_fops =
>> {
>> .supported_type_groups = mdev_type_groups,
>> .create = mtty_create,
>> .remove = mtty_remove,
>> - .open = mtty_open,
>> - .release = mtty_close,
>> - .read = mtty_read,
>> - .write = mtty_write,
>> - .ioctl = mtty_ioctl,
>> };
>>
>> static void mtty_device_release(struct device *dev)
>> --
>> 2.19.1
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 5/6] virtio: introduce a mdev based transport
2019-10-21 5:59 ` Jason Wang
@ 2019-10-21 9:36 ` Cornelia Huck
2019-10-21 10:13 ` Jason Wang
0 siblings, 1 reply; 27+ messages in thread
From: Cornelia Huck @ 2019-10-21 9:36 UTC (permalink / raw)
To: Jason Wang
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On Mon, 21 Oct 2019 13:59:23 +0800
Jason Wang <jasowang@redhat.com> wrote:
> On 2019/10/18 下午10:20, Cornelia Huck wrote:
> > On Thu, 17 Oct 2019 18:48:35 +0800
> > Jason Wang <jasowang@redhat.com> wrote:
> >
> >> This patch introduces a new mdev transport for virtio. This is used to
> >> use kernel virtio driver to drive the mediated device that is capable
> >> of populating virtqueue directly.
> >>
> >> A new virtio-mdev driver will be registered to the mdev bus, when a
> >> new virtio-mdev device is probed, it will register the device with
> >> mdev based config ops. This means it is a software transport between
> >> mdev driver and mdev device. The transport was implemented through
> >> device specific ops which is a part of mdev_parent_ops now.
> >>
> >> Signed-off-by: Jason Wang <jasowang@redhat.com>
> >> ---
> >> drivers/virtio/Kconfig | 7 +
> >> drivers/virtio/Makefile | 1 +
> >> drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++
> >> 3 files changed, 417 insertions(+)
> > (...)
> >
> >> +static int virtio_mdev_probe(struct device *dev)
> >> +{
> >> + struct mdev_device *mdev = mdev_from_dev(dev);
> >> + const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
> >> + struct virtio_mdev_device *vm_dev;
> >> + int rc;
> >> +
> >> + vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL);
> >> + if (!vm_dev)
> >> + return -ENOMEM;
> >> +
> >> + vm_dev->vdev.dev.parent = dev;
> >> + vm_dev->vdev.dev.release = virtio_mdev_release_dev;
> >> + vm_dev->vdev.config = &virtio_mdev_config_ops;
> >> + vm_dev->mdev = mdev;
> >> + INIT_LIST_HEAD(&vm_dev->virtqueues);
> >> + spin_lock_init(&vm_dev->lock);
> >> +
> >> + vm_dev->version = ops->get_mdev_features(mdev);
> >> + if (vm_dev->version != VIRTIO_MDEV_F_VERSION_1) {
> >> + dev_err(dev, "VIRTIO_MDEV_F_VERSION_1 is mandatory\n");
> >> + return -ENXIO;
> >> + }
> > Hm, so how is that mdev features interface supposed to work? If
> > VIRTIO_MDEV_F_VERSION_1 is a bit, I would expect this code to test for
> > its presence, and not for identity.
>
>
> This should be used by driver to detect the which sets of functions and
> their semantics that could be provided by the device. E.g when driver
> support both version 2 and version 1 but device only support version 1,
> driver can switch to use version 1. Btw, Is there a easy way for to test
> its presence or do you mean doing sanity testing on existence of the
> mandatory ops that provided by the device?
What I meant was something like:
features = ops->get_mdev_features(mdev);
if (features & VIRTIO_MDEV_F_VERSION_1)
vm_dev->version = 1;
else
//moan about missing support for version 1
Can there be class id specific extra features, or is this only for core
features? If the latter, maybe also do something like
supported_features = ORED_LIST_OF_FEATURES;
if (features & ~supported_features)
//moan about extra feature bits
>
>
> >
> > What will happen if we come up with a version 2? If this is backwards
> > compatible, will both version 2 and version 1 be set?
>
>
> Yes, I think so, and version 2 should be considered as some extensions
> of version 1. If it's completely, it should use a new class id.
Ok, that makes sense.
^ permalink raw reply [flat|nested] 27+ messages in thread
* Re: [PATCH V4 5/6] virtio: introduce a mdev based transport
2019-10-21 9:36 ` Cornelia Huck
@ 2019-10-21 10:13 ` Jason Wang
0 siblings, 0 replies; 27+ messages in thread
From: Jason Wang @ 2019-10-21 10:13 UTC (permalink / raw)
To: Cornelia Huck
Cc: kvm, linux-s390, linux-kernel, dri-devel, intel-gfx,
intel-gvt-dev, kwankhede, alex.williamson, mst, tiwei.bie,
virtualization, netdev, maxime.coquelin, cunming.liang,
zhihong.wang, rob.miller, xiao.w.wang, haotian.wang, zhenyuw,
zhi.a.wang, jani.nikula, joonas.lahtinen, rodrigo.vivi, airlied,
daniel, farman, pasic, sebott, oberpar, heiko.carstens, gor,
borntraeger, akrowiak, freude, lingshan.zhu, idos, eperezma,
lulu, parav, christophe.de.dinechin, kevin.tian, stefanha
On 2019/10/21 下午5:36, Cornelia Huck wrote:
> On Mon, 21 Oct 2019 13:59:23 +0800
> Jason Wang <jasowang@redhat.com> wrote:
>
>> On 2019/10/18 下午10:20, Cornelia Huck wrote:
>>> On Thu, 17 Oct 2019 18:48:35 +0800
>>> Jason Wang <jasowang@redhat.com> wrote:
>>>
>>>> This patch introduces a new mdev transport for virtio. This is used to
>>>> use kernel virtio driver to drive the mediated device that is capable
>>>> of populating virtqueue directly.
>>>>
>>>> A new virtio-mdev driver will be registered to the mdev bus, when a
>>>> new virtio-mdev device is probed, it will register the device with
>>>> mdev based config ops. This means it is a software transport between
>>>> mdev driver and mdev device. The transport was implemented through
>>>> device specific ops which is a part of mdev_parent_ops now.
>>>>
>>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>>> ---
>>>> drivers/virtio/Kconfig | 7 +
>>>> drivers/virtio/Makefile | 1 +
>>>> drivers/virtio/virtio_mdev.c | 409 +++++++++++++++++++++++++++++++++++
>>>> 3 files changed, 417 insertions(+)
>>> (...)
>>>
>>>> +static int virtio_mdev_probe(struct device *dev)
>>>> +{
>>>> + struct mdev_device *mdev = mdev_from_dev(dev);
>>>> + const struct virtio_mdev_device_ops *ops = mdev_get_dev_ops(mdev);
>>>> + struct virtio_mdev_device *vm_dev;
>>>> + int rc;
>>>> +
>>>> + vm_dev = devm_kzalloc(dev, sizeof(*vm_dev), GFP_KERNEL);
>>>> + if (!vm_dev)
>>>> + return -ENOMEM;
>>>> +
>>>> + vm_dev->vdev.dev.parent = dev;
>>>> + vm_dev->vdev.dev.release = virtio_mdev_release_dev;
>>>> + vm_dev->vdev.config = &virtio_mdev_config_ops;
>>>> + vm_dev->mdev = mdev;
>>>> + INIT_LIST_HEAD(&vm_dev->virtqueues);
>>>> + spin_lock_init(&vm_dev->lock);
>>>> +
>>>> + vm_dev->version = ops->get_mdev_features(mdev);
>>>> + if (vm_dev->version != VIRTIO_MDEV_F_VERSION_1) {
>>>> + dev_err(dev, "VIRTIO_MDEV_F_VERSION_1 is mandatory\n");
>>>> + return -ENXIO;
>>>> + }
>>> Hm, so how is that mdev features interface supposed to work? If
>>> VIRTIO_MDEV_F_VERSION_1 is a bit, I would expect this code to test for
>>> its presence, and not for identity.
>>
>> This should be used by driver to detect the which sets of functions and
>> their semantics that could be provided by the device. E.g when driver
>> support both version 2 and version 1 but device only support version 1,
>> driver can switch to use version 1. Btw, Is there a easy way for to test
>> its presence or do you mean doing sanity testing on existence of the
>> mandatory ops that provided by the device?
> What I meant was something like:
>
> features = ops->get_mdev_features(mdev);
> if (features & VIRTIO_MDEV_F_VERSION_1)
> vm_dev->version = 1;
> else
> //moan about missing support for version 1
>
> Can there be class id specific extra features, or is this only for core
> features? If the latter, maybe also do something like
>
> supported_features = ORED_LIST_OF_FEATURES;
> if (features & ~supported_features)
> //moan about extra feature bits
Consider driver can claim to support a list of ids, so I this it's former.
Will do as what you proposed.
Thanks
>
>>
>>> What will happen if we come up with a version 2? If this is backwards
>>> compatible, will both version 2 and version 1 be set?
>>
>> Yes, I think so, and version 2 should be considered as some extensions
>> of version 1. If it's completely, it should use a new class id.
> Ok, that makes sense.
>
^ permalink raw reply [flat|nested] 27+ messages in thread
end of thread, other threads:[~2019-10-21 10:13 UTC | newest]
Thread overview: 27+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-10-17 10:48 [PATCH V4 0/6] mdev based hardware virtio offloading support Jason Wang
2019-10-17 10:48 ` [PATCH V4 1/6] mdev: class id support Jason Wang
2019-10-20 23:25 ` Parav Pandit
2019-10-17 10:48 ` [PATCH V4 2/6] modpost: add support for mdev class id Jason Wang
2019-10-20 23:25 ` Parav Pandit
2019-10-17 10:48 ` [PATCH V4 3/6] mdev: introduce device specific ops Jason Wang
2019-10-17 15:07 ` Cornelia Huck
2019-10-17 17:53 ` Alex Williamson
2019-10-18 7:44 ` Cornelia Huck
2019-10-18 7:34 ` Jason Wang
2019-10-20 23:41 ` Parav Pandit
2019-10-21 6:02 ` Jason Wang
2019-10-17 10:48 ` [PATCH V4 4/6] mdev: introduce virtio device and its device ops Jason Wang
2019-10-17 17:53 ` Alex Williamson
2019-10-18 7:35 ` Jason Wang
2019-10-18 9:46 ` Cornelia Huck
2019-10-18 10:55 ` Jason Wang
2019-10-18 13:30 ` Cornelia Huck
2019-10-21 5:36 ` Jason Wang
2019-10-18 9:46 ` Tiwei Bie
2019-10-18 10:57 ` Jason Wang
2019-10-17 10:48 ` [PATCH V4 5/6] virtio: introduce a mdev based transport Jason Wang
2019-10-18 14:20 ` Cornelia Huck
2019-10-21 5:59 ` Jason Wang
2019-10-21 9:36 ` Cornelia Huck
2019-10-21 10:13 ` Jason Wang
2019-10-17 10:48 ` [PATCH V4 6/6] docs: sample driver to demonstrate how to implement virtio-mdev framework Jason Wang
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