Re: [Intel-gfx] [PATCH v2 6/9] vfio/mdev: Add mdev available instance checking to the core
On Tue, 2021-09-21 at 10:19 -0300, Jason Gunthorpe wrote: > On Mon, Sep 20, 2021 at 08:02:29PM +0200, Cornelia Huck wrote: > > On Thu, Sep 09 2021, Jason Gunthorpe wrote: > > > > > Many of the mdev drivers use a simple counter for keeping track > > > of the > > > available instances. Move this code to the core code and store > > > the counter > > > in the mdev_type. Implement it using correct locking, fixing > > > mdpy. > > > > > > Drivers provide a get_available() callback to set the number of > > > available > > > instances for their mtypes which is fixed at registration time. > > > The core > > > provides a standard sysfs attribute to return the > > > available_instances. > > > > So, according to the documentation, available_instances is > > mandatory. This means that drivers either need to provide > > get_available > > or implement their own version of the attribute. I think we want to > > update vfio-mediated-device.rst as well? > > I added this, and something similar for the device_api patch too, > thanks > > diff --git a/Documentation/driver-api/vfio-mediated-device.rst > b/Documentation/driver-api/vfio-mediated-device.rst > index 9f26079cacae35..0a130d76b33a48 100644 > --- a/Documentation/driver-api/vfio-mediated-device.rst > +++ b/Documentation/driver-api/vfio-mediated-device.rst > @@ -106,6 +106,7 @@ structure to represent a mediated device's > driver:: >int (*probe) (struct mdev_device *dev); >void (*remove) (struct mdev_device *dev); >struct device_driverdriver; > + unsigned int (*get_available)(struct mdev_type *mtype); > }; > > A mediated bus driver for mdev should use this structure in the > function calls > @@ -230,7 +231,8 @@ Directories and files under the sysfs for Each > Physical Device > * available_instances > >This attribute should show the number of devices of type > that can be > - created. > + created. Drivers can supply a get_availble() function pointer to s/availble/available/ > have the core > + code create and maintain this sysfs automatically. > > * [device] >
Re: [Intel-gfx] [PATCH v2 6/9] vfio/mdev: Add mdev available instance checking to the core
On Mon, Sep 20, 2021 at 08:02:29PM +0200, Cornelia Huck wrote: > On Thu, Sep 09 2021, Jason Gunthorpe wrote: > > > Many of the mdev drivers use a simple counter for keeping track of the > > available instances. Move this code to the core code and store the counter > > in the mdev_type. Implement it using correct locking, fixing mdpy. > > > > Drivers provide a get_available() callback to set the number of available > > instances for their mtypes which is fixed at registration time. The core > > provides a standard sysfs attribute to return the available_instances. > > So, according to the documentation, available_instances is > mandatory. This means that drivers either need to provide get_available > or implement their own version of the attribute. I think we want to > update vfio-mediated-device.rst as well? I added this, and something similar for the device_api patch too, thanks diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentation/driver-api/vfio-mediated-device.rst index 9f26079cacae35..0a130d76b33a48 100644 --- a/Documentation/driver-api/vfio-mediated-device.rst +++ b/Documentation/driver-api/vfio-mediated-device.rst @@ -106,6 +106,7 @@ structure to represent a mediated device's driver:: int (*probe) (struct mdev_device *dev); void (*remove) (struct mdev_device *dev); struct device_driverdriver; +unsigned int (*get_available)(struct mdev_type *mtype); }; A mediated bus driver for mdev should use this structure in the function calls @@ -230,7 +231,8 @@ Directories and files under the sysfs for Each Physical Device * available_instances This attribute should show the number of devices of type that can be - created. + created. Drivers can supply a get_availble() function pointer to have the core + code create and maintain this sysfs automatically. * [device]
Re: [Intel-gfx] [PATCH v2 6/9] vfio/mdev: Add mdev available instance checking to the core
On Thu, Sep 09 2021, Jason Gunthorpe wrote: > Many of the mdev drivers use a simple counter for keeping track of the > available instances. Move this code to the core code and store the counter > in the mdev_type. Implement it using correct locking, fixing mdpy. > > Drivers provide a get_available() callback to set the number of available > instances for their mtypes which is fixed at registration time. The core > provides a standard sysfs attribute to return the available_instances. So, according to the documentation, available_instances is mandatory. This means that drivers either need to provide get_available or implement their own version of the attribute. I think we want to update vfio-mediated-device.rst as well? > > Signed-off-by: Jason Gunthorpe > --- > drivers/s390/cio/vfio_ccw_drv.c | 1 - > drivers/s390/cio/vfio_ccw_ops.c | 26 ++- > drivers/s390/cio/vfio_ccw_private.h | 2 -- > drivers/s390/crypto/vfio_ap_ops.c | 32 ++- > drivers/s390/crypto/vfio_ap_private.h | 2 -- > drivers/vfio/mdev/mdev_core.c | 11 +++- > drivers/vfio/mdev/mdev_private.h | 2 ++ > drivers/vfio/mdev/mdev_sysfs.c| 37 +++ > include/linux/mdev.h | 2 ++ > samples/vfio-mdev/mdpy.c | 22 +--- > 10 files changed, 73 insertions(+), 64 deletions(-) Otherwise, looks good.
Re: [Intel-gfx] [PATCH v2 6/9] vfio/mdev: Add mdev available instance checking to the core
On Thu, Sep 09, 2021 at 04:38:46PM -0300, Jason Gunthorpe wrote: > Many of the mdev drivers use a simple counter for keeping track of the > available instances. Move this code to the core code and store the counter > in the mdev_type. Implement it using correct locking, fixing mdpy. > > Drivers provide a get_available() callback to set the number of available > instances for their mtypes which is fixed at registration time. The core > provides a standard sysfs attribute to return the available_instances. Looks good, Reviewed-by: Christoph Hellwig
[Intel-gfx] [PATCH v2 6/9] vfio/mdev: Add mdev available instance checking to the core
Many of the mdev drivers use a simple counter for keeping track of the
available instances. Move this code to the core code and store the counter
in the mdev_type. Implement it using correct locking, fixing mdpy.
Drivers provide a get_available() callback to set the number of available
instances for their mtypes which is fixed at registration time. The core
provides a standard sysfs attribute to return the available_instances.
Signed-off-by: Jason Gunthorpe
---
drivers/s390/cio/vfio_ccw_drv.c | 1 -
drivers/s390/cio/vfio_ccw_ops.c | 26 ++-
drivers/s390/cio/vfio_ccw_private.h | 2 --
drivers/s390/crypto/vfio_ap_ops.c | 32 ++-
drivers/s390/crypto/vfio_ap_private.h | 2 --
drivers/vfio/mdev/mdev_core.c | 11 +++-
drivers/vfio/mdev/mdev_private.h | 2 ++
drivers/vfio/mdev/mdev_sysfs.c| 37 +++
include/linux/mdev.h | 2 ++
samples/vfio-mdev/mdpy.c | 22 +---
10 files changed, 73 insertions(+), 64 deletions(-)
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 99f2823361718f..de782e967a5474 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -106,7 +106,6 @@ static struct vfio_ccw_private
*vfio_ccw_alloc_private(struct subchannel *sch)
INIT_LIST_HEAD(>crw);
INIT_WORK(>io_work, vfio_ccw_sch_io_todo);
INIT_WORK(>crw_work, vfio_ccw_crw_todo);
- atomic_set(>avail, 1);
private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
GFP_KERNEL);
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 18a48d1f1e8fff..38ab5c1f25ec09 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -70,20 +70,9 @@ static ssize_t name_show(struct mdev_type *mtype,
}
static MDEV_TYPE_ATTR_RO(name);
-static ssize_t available_instances_show(struct mdev_type *mtype,
- struct mdev_type_attribute *attr,
- char *buf)
-{
- struct vfio_ccw_private *private =
- dev_get_drvdata(mtype_get_parent_dev(mtype));
-
- return sprintf(buf, "%d\n", atomic_read(>avail));
-}
-static MDEV_TYPE_ATTR_RO(available_instances);
static struct attribute *mdev_types_attrs[] = {
_type_attr_name.attr,
- _type_attr_available_instances.attr,
NULL,
};
@@ -102,9 +91,6 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
int ret;
- if (atomic_dec_if_positive(>avail) < 0)
- return -EPERM;
-
memset(>vdev, 0, sizeof(private->vdev));
vfio_init_group_dev(>vdev, >dev,
_ccw_dev_ops);
@@ -118,13 +104,12 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
ret = vfio_register_group_dev(>vdev);
if (ret)
- goto err_atomic;
+ goto err_init;
dev_set_drvdata(>dev, private);
return 0;
-err_atomic:
+err_init:
vfio_uninit_group_dev(>vdev);
- atomic_inc(>avail);
private->mdev = NULL;
return ret;
}
@@ -141,7 +126,6 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
vfio_unregister_group_dev(>vdev);
vfio_uninit_group_dev(>vdev);
private->mdev = NULL;
- atomic_inc(>avail);
}
static int vfio_ccw_mdev_open_device(struct vfio_device *vdev)
@@ -610,6 +594,11 @@ static void vfio_ccw_mdev_request(struct vfio_device
*vdev, unsigned int count)
}
}
+static unsigned int vfio_ccw_get_available(struct mdev_type *mtype)
+{
+ return 1;
+}
+
static const struct vfio_device_ops vfio_ccw_dev_ops = {
.open_device = vfio_ccw_mdev_open_device,
.close_device = vfio_ccw_mdev_close_device,
@@ -627,6 +616,7 @@ struct mdev_driver vfio_ccw_mdev_driver = {
},
.probe = vfio_ccw_mdev_probe,
.remove = vfio_ccw_mdev_remove,
+ .get_available = vfio_ccw_get_available,
};
static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
diff --git a/drivers/s390/cio/vfio_ccw_private.h
b/drivers/s390/cio/vfio_ccw_private.h
index 5e98eacdf31074..bbc97eb9d9c6fc 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -72,7 +72,6 @@ struct vfio_ccw_crw {
* @sch: pointer to the subchannel
* @state: internal state of the device
* @completion: synchronization helper of the I/O completion
- * @avail: available for creating a mediated device
* @mdev: pointer to the mediated device
* @nb: notifier for vfio events
* @io_region: MMIO region to input/output I/O arguments/results
@@ -96,7 +95,6 @@ struct vfio_ccw_private {
struct subchannel *sch;
int state;
struct completion
