Chris Wright wrote: > This adds a remove_id sysfs entry to allow users of new_id to later > remove the added dynid. One use case is management tools that want to > dynamically bind/unbind devices to pci-stub driver while devices are > assigned to KVM guests. Rather than having to track which driver was > originally bound to the driver, a mangement tool can simply: > > # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/new_id > # echo 0000:00:19.0 > /sys/bus/pci/devices/0000:00:19.0/driver/unbind > # echo 0000:00:19.0 > /sys/bus/pci/drivers/pci-stub/bind > > Guest uses device > > # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/remove_id > # echo 0000:00:19.0 > /sys/bus/pci/drivers_probe >
After above two commands, I found device 00:19.0 was still bound to pci-stub, and doesn't work. I found it needs following unbind command between remove_id and drivers_probe to make it work with original driver: # echo "8086 10f5" > /sys/bus/pci/drivers/pci-stub/unbind Chris, did it also happen on your side? or did I miss something? Regards, Weidong > Signed-off-by: Chris Wright <[email protected]> > --- > v2 > - update changelog to match ABI docs (remove echo -n) > > Documentation/ABI/testing/sysfs-bus-pci | 16 ++++++ > drivers/pci/pci-driver.c | 80 > +++++++++++++++++++++++++++++++- 2 files changed, 94 insertions(+), > 2 deletions(-) > > --- a/drivers/pci/pci-driver.c > +++ b/drivers/pci/pci-driver.c > @@ -99,6 +99,52 @@ store_new_id(struct device_driver *drive > } > static DRIVER_ATTR(new_id, S_IWUSR, NULL, store_new_id); > > +/** > + * store_remove_id - remove a PCI device ID from this driver > + * @driver: target device driver > + * @buf: buffer for scanning device ID data > + * @count: input size > + * > + * Removes a dynamic pci device ID to this driver. > + */ > +static ssize_t > +store_remove_id(struct device_driver *driver, const char *buf, > size_t count) +{ > + struct pci_dynid *dynid, *n; > + struct pci_driver *pdrv = to_pci_driver(driver); > + __u32 vendor, device, subvendor = PCI_ANY_ID, > + subdevice = PCI_ANY_ID, class = 0, class_mask = 0; > + int fields = 0; > + int retval = -ENODEV; > + > + fields = sscanf(buf, "%x %x %x %x %x %x", > + &vendor, &device, &subvendor, &subdevice, > + &class, &class_mask); > + if (fields < 2) > + return -EINVAL; > + > + spin_lock(&pdrv->dynids.lock); > + list_for_each_entry_safe(dynid, n, &pdrv->dynids.list, node) { > + struct pci_device_id *id = &dynid->id; > + if ((id->vendor == vendor) && > + (id->device == device) && > + (subvendor == PCI_ANY_ID || id->subvendor == subvendor) && > + (subdevice == PCI_ANY_ID || id->subdevice == subdevice) && > + !((id->class ^ class) & class_mask)) { > + list_del(&dynid->node); > + kfree(dynid); > + retval = 0; > + break; > + } > + } > + spin_unlock(&pdrv->dynids.lock); > + > + if (retval) > + return retval; > + return count; > +} > +static DRIVER_ATTR(remove_id, S_IWUSR, NULL, store_remove_id); > + > static void > pci_free_dynids(struct pci_driver *drv) > { > @@ -125,6 +171,20 @@ static void pci_remove_newid_file(struct > { > driver_remove_file(&drv->driver, &driver_attr_new_id); > } > + > +static int > +pci_create_removeid_file(struct pci_driver *drv) > +{ > + int error = 0; > + if (drv->probe != NULL) > + error = driver_create_file(&drv->driver,&driver_attr_remove_id); > + return error; > +} > + > +static void pci_remove_removeid_file(struct pci_driver *drv) > +{ > + driver_remove_file(&drv->driver, &driver_attr_remove_id); > +} > #else /* !CONFIG_HOTPLUG */ > static inline void pci_free_dynids(struct pci_driver *drv) {} > static inline int pci_create_newid_file(struct pci_driver *drv) > @@ -132,6 +192,11 @@ static inline int pci_create_newid_file( > return 0; > } > static inline void pci_remove_newid_file(struct pci_driver *drv) {} > +static inline int pci_create_removeid_file(struct pci_driver *drv) > +{ > + return 0; > +} > +static inline void pci_remove_removeid_file(struct pci_driver *drv) > {} #endif > > /** > @@ -852,13 +917,23 @@ int __pci_register_driver(struct pci_dri > /* register with core */ > error = driver_register(&drv->driver); > if (error) > - return error; > + goto out; > > error = pci_create_newid_file(drv); > if (error) > - driver_unregister(&drv->driver); > + goto out_newid; > > + error = pci_create_removeid_file(drv); > + if (error) > + goto out_removeid; > +out: > return error; > + > +out_removeid: > + pci_remove_newid_file(drv); > +out_newid: > + driver_unregister(&drv->driver); > + goto out; > } > > /** > @@ -874,6 +949,7 @@ int __pci_register_driver(struct pci_dri > void > pci_unregister_driver(struct pci_driver *drv) > { > + pci_remove_removeid_file(drv); > pci_remove_newid_file(drv); > driver_unregister(&drv->driver); > pci_free_dynids(drv); > --- a/Documentation/ABI/testing/sysfs-bus-pci > +++ b/Documentation/ABI/testing/sysfs-bus-pci > @@ -41,6 +41,22 @@ Description: > for the device and attempt to bind to it. For example: > # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id > > +What: /sys/bus/pci/drivers/.../remove_id > +Date: February 2009 > +Contact: Chris Wright <[email protected]> > +Description: > + Writing a device ID to this file will remove an ID > + that was dynamically added via the new_id sysfs entry. > + The format for the device ID is: > + VVVV DDDD SVVV SDDD CCCC MMMM. That is Vendor ID, Device > + ID, Subsystem Vendor ID, Subsystem Device ID, Class, > + and Class Mask. The Vendor ID and Device ID fields are > + required, the rest are optional. After successfully > + removing an ID, the driver will no longer support the > + device. This is useful to ensure auto probing won't > + match the driver to the device. For example: > + # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id > + > What: /sys/bus/pci/devices/.../vpd > Date: February 2008 > Contact: Ben Hutchings <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
