On Fri, Nov 5, 2021 at 12:17 AM Stefano Garzarella <sgarzare at redhat.com> wrote:> > `driver_override` allows to control which of the vDPA bus drivers > binds to a vDPA device. > > If `driver_override` is not set, the previous behaviour is followed: > devices use the first vDPA bus driver loaded (unless auto binding > is disabled). > > Tested on Fedora 34 with driverctl(8): > $ modprobe virtio-vdpa > $ modprobe vhost-vdpa > $ modprobe vdpa-sim-net > > $ vdpa dev add mgmtdev vdpasim_net name dev1 > > # dev1 is attached to the first vDPA bus driver loaded > $ driverctl -b vdpa list-devices > dev1 virtio_vdpa > > $ driverctl -b vdpa set-override dev1 vhost_vdpa > > $ driverctl -b vdpa list-devices > dev1 vhost_vdpa [*] > > Note: driverctl(8) integrates with udev so the binding is > preserved. > > Suggested-by: Jason Wang <jasowang at redhat.com> > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > --- > include/linux/vdpa.h | 2 ++ > drivers/vdpa/vdpa.c | 74 ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 76 insertions(+) > > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > index c3011ccda430..ae34015b37b7 100644 > --- a/include/linux/vdpa.h > +++ b/include/linux/vdpa.h > @@ -64,6 +64,7 @@ struct vdpa_mgmt_dev; > * struct vdpa_device - representation of a vDPA device > * @dev: underlying device > * @dma_dev: the actual device that is performing DMA > + * @driver_override: driver name to force a matchThis seems useless?> * @config: the configuration ops for this device. > * @cf_mutex: Protects get and set access to configuration layout. > * @index: device index > @@ -76,6 +77,7 @@ struct vdpa_mgmt_dev; > struct vdpa_device { > struct device dev; > struct device *dma_dev; > + const char *driver_override; > const struct vdpa_config_ops *config; > struct mutex cf_mutex; /* Protects get/set config */ > unsigned int index; > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index 7332a74a4b00..659231bbfee8 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -52,8 +52,81 @@ static void vdpa_dev_remove(struct device *d) > drv->remove(vdev); > } > > +static int vdpa_dev_match(struct device *dev, struct device_driver *drv) > +{ > + struct vdpa_device *vdev = dev_to_vdpa(dev); > + > + /* Check override first, and if set, only use the named driver */ > + if (vdev->driver_override) > + return strcmp(vdev->driver_override, drv->name) == 0; > + > + /* Currently devices must be supported by all vDPA bus drivers */ > + return 1; > +} > + > +static ssize_t driver_override_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct vdpa_device *vdev = dev_to_vdpa(dev); > + const char *driver_override, *old; > + char *cp; > + > + /* We need to keep extra room for a newline */ > + if (count >= (PAGE_SIZE - 1)) > + return -EINVAL; > + > + driver_override = kstrndup(buf, count, GFP_KERNEL); > + if (!driver_override) > + return -ENOMEM; > + > + cp = strchr(driver_override, '\n'); > + if (cp) > + *cp = '\0'; > + > + device_lock(dev); > + old = vdev->driver_override; > + if (strlen(driver_override)) { > + vdev->driver_override = driver_override; > + } else { > + kfree(driver_override); > + vdev->driver_override = NULL; > + } > + device_unlock(dev); > + > + kfree(old); > + > + return count; > +} > + > +static ssize_t driver_override_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct vdpa_device *vdev = dev_to_vdpa(dev); > + ssize_t len; > + > + device_lock(dev); > + len = snprintf(buf, PAGE_SIZE, "%s\n", vdev->driver_override); > + device_unlock(dev); > + > + return len; > +} > +static DEVICE_ATTR_RW(driver_override); > + > +static struct attribute *vdpa_dev_attrs[] = { > + &dev_attr_driver_override.attr, > + NULL, > +}; > + > +static const struct attribute_group vdpa_dev_group = { > + .attrs = vdpa_dev_attrs, > +}; > +__ATTRIBUTE_GROUPS(vdpa_dev); > + > static struct bus_type vdpa_bus = { > .name = "vdpa", > + .dev_groups = vdpa_dev_groups,This reminds me that we probably need to document the sysfs interface in Documentation/ABI/testing/sysfs-bus-vdpa. But it's not the fault of this patch which look good. Thanks> + .match = vdpa_dev_match, > .probe = vdpa_dev_probe, > .remove = vdpa_dev_remove, > }; > @@ -68,6 +141,7 @@ static void vdpa_release_dev(struct device *d) > > ida_simple_remove(&vdpa_index_ida, vdev->index); > mutex_destroy(&vdev->cf_mutex); > + kfree(vdev->driver_override); > kfree(vdev); > } > > -- > 2.31.1 >
On Fri, Nov 05, 2021 at 11:01:30AM +0800, Jason Wang wrote:>On Fri, Nov 5, 2021 at 12:17 AM Stefano Garzarella <sgarzare at redhat.com> wrote: >> >> `driver_override` allows to control which of the vDPA bus drivers >> binds to a vDPA device. >> >> If `driver_override` is not set, the previous behaviour is followed: >> devices use the first vDPA bus driver loaded (unless auto binding >> is disabled). >> >> Tested on Fedora 34 with driverctl(8): >> $ modprobe virtio-vdpa >> $ modprobe vhost-vdpa >> $ modprobe vdpa-sim-net >> >> $ vdpa dev add mgmtdev vdpasim_net name dev1 >> >> # dev1 is attached to the first vDPA bus driver loaded >> $ driverctl -b vdpa list-devices >> dev1 virtio_vdpa >> >> $ driverctl -b vdpa set-override dev1 vhost_vdpa >> >> $ driverctl -b vdpa list-devices >> dev1 vhost_vdpa [*] >> >> Note: driverctl(8) integrates with udev so the binding is >> preserved. >> >> Suggested-by: Jason Wang <jasowang at redhat.com> >> Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> >> --- >> include/linux/vdpa.h | 2 ++ >> drivers/vdpa/vdpa.c | 74 ++++++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 76 insertions(+) >> >> diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h >> index c3011ccda430..ae34015b37b7 100644 >> --- a/include/linux/vdpa.h >> +++ b/include/linux/vdpa.h >> @@ -64,6 +64,7 @@ struct vdpa_mgmt_dev; >> * struct vdpa_device - representation of a vDPA device >> * @dev: underlying device >> * @dma_dev: the actual device that is performing DMA >> + * @driver_override: driver name to force a match > >This seems useless?I'm a bit lost, do you mean we should remove the documentation of `driver_override`?> >> * @config: the configuration ops for this device. >> * @cf_mutex: Protects get and set access to configuration layout. >> * @index: device index >> @@ -76,6 +77,7 @@ struct vdpa_mgmt_dev; >> struct vdpa_device { >> struct device dev; >> struct device *dma_dev; >> + const char *driver_override; >> const struct vdpa_config_ops *config; >> struct mutex cf_mutex; /* Protects get/set config */ >> unsigned int index; >> diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c >> index 7332a74a4b00..659231bbfee8 100644 >> --- a/drivers/vdpa/vdpa.c >> +++ b/drivers/vdpa/vdpa.c >> @@ -52,8 +52,81 @@ static void vdpa_dev_remove(struct device *d) >> drv->remove(vdev); >> } >> >> +static int vdpa_dev_match(struct device *dev, struct device_driver *drv) >> +{ >> + struct vdpa_device *vdev = dev_to_vdpa(dev); >> + >> + /* Check override first, and if set, only use the named driver */ >> + if (vdev->driver_override) >> + return strcmp(vdev->driver_override, drv->name) == 0; >> + >> + /* Currently devices must be supported by all vDPA bus >> drivers */ >> + return 1; >> +} >> + >> +static ssize_t driver_override_store(struct device *dev, >> + struct device_attribute *attr, >> + const char *buf, size_t count) >> +{ >> + struct vdpa_device *vdev = dev_to_vdpa(dev); >> + const char *driver_override, *old; >> + char *cp; >> + >> + /* We need to keep extra room for a newline */ >> + if (count >= (PAGE_SIZE - 1)) >> + return -EINVAL; >> + >> + driver_override = kstrndup(buf, count, GFP_KERNEL); >> + if (!driver_override) >> + return -ENOMEM; >> + >> + cp = strchr(driver_override, '\n'); >> + if (cp) >> + *cp = '\0'; >> + >> + device_lock(dev); >> + old = vdev->driver_override; >> + if (strlen(driver_override)) { >> + vdev->driver_override = driver_override; >> + } else { >> + kfree(driver_override); >> + vdev->driver_override = NULL; >> + } >> + device_unlock(dev); >> + >> + kfree(old); >> + >> + return count; >> +} >> + >> +static ssize_t driver_override_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct vdpa_device *vdev = dev_to_vdpa(dev); >> + ssize_t len; >> + >> + device_lock(dev); >> + len = snprintf(buf, PAGE_SIZE, "%s\n", vdev->driver_override); >> + device_unlock(dev); >> + >> + return len; >> +} >> +static DEVICE_ATTR_RW(driver_override); >> + >> +static struct attribute *vdpa_dev_attrs[] = { >> + &dev_attr_driver_override.attr, >> + NULL, >> +}; >> + >> +static const struct attribute_group vdpa_dev_group = { >> + .attrs = vdpa_dev_attrs, >> +}; >> +__ATTRIBUTE_GROUPS(vdpa_dev); >> + >> static struct bus_type vdpa_bus = { >> .name = "vdpa", >> + .dev_groups = vdpa_dev_groups, > >This reminds me that we probably need to document the sysfs interface >in Documentation/ABI/testing/sysfs-bus-vdpa. >Yeah, I'd like to add more documentation. We should also document the device life cycle and management API. It's on my to-do list, I'm prioritizing it!>But it's not the fault of this patch which look good.Thanks, Stefano
On Fri, Nov 5, 2021 at 4:01 AM Jason Wang <jasowang at redhat.com> wrote:> > On Fri, Nov 5, 2021 at 12:17 AM Stefano Garzarella <sgarzare at redhat.com> wrote: > > > > `driver_override` allows to control which of the vDPA bus drivers > > binds to a vDPA device. > > > > If `driver_override` is not set, the previous behaviour is followed: > > devices use the first vDPA bus driver loaded (unless auto binding > > is disabled). > > > > Tested on Fedora 34 with driverctl(8): > > $ modprobe virtio-vdpa > > $ modprobe vhost-vdpa > > $ modprobe vdpa-sim-net > > > > $ vdpa dev add mgmtdev vdpasim_net name dev1 > > > > # dev1 is attached to the first vDPA bus driver loaded > > $ driverctl -b vdpa list-devices > > dev1 virtio_vdpa > > > > $ driverctl -b vdpa set-override dev1 vhost_vdpa > > > > $ driverctl -b vdpa list-devices > > dev1 vhost_vdpa [*] > > > > Note: driverctl(8) integrates with udev so the binding is > > preserved. > > > > Suggested-by: Jason Wang <jasowang at redhat.com> > > Signed-off-by: Stefano Garzarella <sgarzare at redhat.com> > > --- > > include/linux/vdpa.h | 2 ++ > > drivers/vdpa/vdpa.c | 74 ++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 76 insertions(+) > > > > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > > index c3011ccda430..ae34015b37b7 100644 > > --- a/include/linux/vdpa.h > > +++ b/include/linux/vdpa.h > > @@ -64,6 +64,7 @@ struct vdpa_mgmt_dev; > > * struct vdpa_device - representation of a vDPA device > > * @dev: underlying device > > * @dma_dev: the actual device that is performing DMA > > + * @driver_override: driver name to force a match > > This seems useless? > > > * @config: the configuration ops for this device. > > * @cf_mutex: Protects get and set access to configuration layout. > > * @index: device index > > @@ -76,6 +77,7 @@ struct vdpa_mgmt_dev; > > struct vdpa_device { > > struct device dev; > > struct device *dma_dev; > > + const char *driver_override; > > const struct vdpa_config_ops *config; > > struct mutex cf_mutex; /* Protects get/set config */ > > unsigned int index; > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > > index 7332a74a4b00..659231bbfee8 100644 > > --- a/drivers/vdpa/vdpa.c > > +++ b/drivers/vdpa/vdpa.c > > @@ -52,8 +52,81 @@ static void vdpa_dev_remove(struct device *d) > > drv->remove(vdev); > > } > > > > +static int vdpa_dev_match(struct device *dev, struct device_driver *drv) > > +{ > > + struct vdpa_device *vdev = dev_to_vdpa(dev); > > + > > + /* Check override first, and if set, only use the named driver */ > > + if (vdev->driver_override) > > + return strcmp(vdev->driver_override, drv->name) == 0; > > + > > + /* Currently devices must be supported by all vDPA bus drivers */ > > + return 1; > > +} > > + > > +static ssize_t driver_override_store(struct device *dev, > > + struct device_attribute *attr, > > + const char *buf, size_t count) > > +{ > > + struct vdpa_device *vdev = dev_to_vdpa(dev); > > + const char *driver_override, *old; > > + char *cp; > > + > > + /* We need to keep extra room for a newline */ > > + if (count >= (PAGE_SIZE - 1)) > > + return -EINVAL; > > + > > + driver_override = kstrndup(buf, count, GFP_KERNEL); > > + if (!driver_override) > > + return -ENOMEM; > > + > > + cp = strchr(driver_override, '\n'); > > + if (cp) > > + *cp = '\0'; > > + > > + device_lock(dev); > > + old = vdev->driver_override; > > + if (strlen(driver_override)) { > > + vdev->driver_override = driver_override; > > + } else { > > + kfree(driver_override); > > + vdev->driver_override = NULL; > > + } > > + device_unlock(dev); > > + > > + kfree(old); > > + > > + return count; > > +} > > + > > +static ssize_t driver_override_show(struct device *dev, > > + struct device_attribute *attr, char *buf) > > +{ > > + struct vdpa_device *vdev = dev_to_vdpa(dev); > > + ssize_t len; > > + > > + device_lock(dev); > > + len = snprintf(buf, PAGE_SIZE, "%s\n", vdev->driver_override); > > + device_unlock(dev); > > + > > + return len; > > +} > > +static DEVICE_ATTR_RW(driver_override); > > + > > +static struct attribute *vdpa_dev_attrs[] = { > > + &dev_attr_driver_override.attr, > > + NULL, > > +}; > > + > > +static const struct attribute_group vdpa_dev_group = { > > + .attrs = vdpa_dev_attrs, > > +}; > > +__ATTRIBUTE_GROUPS(vdpa_dev); > > + > > static struct bus_type vdpa_bus = { > > .name = "vdpa", > > + .dev_groups = vdpa_dev_groups, > > This reminds me that we probably need to document the sysfs interface > in Documentation/ABI/testing/sysfs-bus-vdpa. > > But it's not the fault of this patch which look good.Michael, Jason, about Documentation/ABI/testing/sysfs-bus-vdpa, do you think is better to send a follow up patch/series, maybe including also others entries (e.g. bind, unbind) or a v2 including the documentation of `driver_ovveride`? Thanks, Stefano