Re: [PATCH v2] PCI: hv: fix pci-hyperv build when SYSFS not enabled

[Randy Dunlap]

On 7/3/19 11:06 AM, Haiyang Zhang wrote:
> 
> 
>> -----Original Message-----
>> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>> Sent: Wednesday, July 3, 2019 12:59 PM
>> To: LKML <linux-kernel@xxxxxxxxxxxxxxx>; linux-pci <linux-
>> pci@xxxxxxxxxxxxxxx>
>> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>; Jake Oshins
>> <jakeo@xxxxxxxxxxxxx>; KY Srinivasan <kys@xxxxxxxxxxxxx>; Haiyang
>> Zhang <haiyangz@xxxxxxxxxxxxx>; Stephen Hemminger
>> <sthemmin@xxxxxxxxxxxxx>; Sasha Levin <sashal@xxxxxxxxxx>; Bjorn
>> Helgaas <bhelgaas@xxxxxxxxxx>; linux-hyperv@xxxxxxxxxxxxxxx; Dexuan
>> Cui <decui@xxxxxxxxxxxxx>; Yuehaibing <yuehaibing@xxxxxxxxxx>
>> Subject: [PATCH v2] PCI: hv: fix pci-hyperv build when SYSFS not enabled
>>
>> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>>
>> Fix build of drivers/pci/controller/pci-hyperv.o when
>> CONFIG_SYSFS is not set/enabled by adding stubs for
>> pci_create_slot() and pci_destroy_slot().
>>
>> Fixes these build errors:
>>
>> ERROR: "pci_destroy_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>> ERROR: "pci_create_slot" [drivers/pci/controller/pci-hyperv.ko] undefined!
>>
>> Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot
>> information")
>>
>> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
>> Cc: Jake Oshins <jakeo@xxxxxxxxxxxxx>
>> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
>> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
>> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
>> Cc: Sasha Levin <sashal@xxxxxxxxxx>
>> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>> Cc: linux-pci@xxxxxxxxxxxxxxx
>> Cc: linux-hyperv@xxxxxxxxxxxxxxx
>> Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
>> Cc: Yuehaibing <yuehaibing@xxxxxxxxxx>
>> ---
>> v2:
>> - provide non-CONFIG_SYSFS stubs for pci_create_slot() and
>>   pci_destroy_slot() [suggested by Matthew Wilcox <willy@xxxxxxxxxxxxx>]
>> - use the correct Fixes: tag [Dexuan Cui <decui@xxxxxxxxxxxxx>]
>>
>>  include/linux/pci.h |   12 ++++++++++--
>>  1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> --- lnx-52-rc7.orig/include/linux/pci.h
>> +++ lnx-52-rc7/include/linux/pci.h
>> @@ -25,6 +25,7 @@
>>  #include <linux/ioport.h>
>>  #include <linux/list.h>
>>  #include <linux/compiler.h>
>> +#include <linux/err.h>
>>  #include <linux/errno.h>
>>  #include <linux/kobject.h>
>>  #include <linux/atomic.h>
>> @@ -947,14 +948,21 @@ int pci_scan_root_bus_bridge(struct pci_
>>  struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev
>> *dev,
>>  				int busnr);
>>  void pcie_update_link_speed(struct pci_bus *bus, u16 link_status);
>> +#ifdef CONFIG_SYSFS
>> +void pci_dev_assign_slot(struct pci_dev *dev);
>>  struct pci_slot *pci_create_slot(struct pci_bus *parent, int slot_nr,
>>  				 const char *name,
>>  				 struct hotplug_slot *hotplug);
>>  void pci_destroy_slot(struct pci_slot *slot);
>> -#ifdef CONFIG_SYSFS
>> -void pci_dev_assign_slot(struct pci_dev *dev);
>>  #else
>>  static inline void pci_dev_assign_slot(struct pci_dev *dev) { }
>> +static inline struct pci_slot *pci_create_slot(struct pci_bus *parent,
>> +					       int slot_nr,
>> +					       const char *name,
>> +					       struct hotplug_slot *hotplug) {
>> +	return ERR_PTR(-EINVAL);
>> +}
>> +static inline void pci_destroy_slot(struct pci_slot *slot) { }
>>  #endif
>>  int pci_scan_slot(struct pci_bus *bus, int devfn);
>>  struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn);
>>
> 
> The serial number in slot info is used to match VF NIC with Synthetic NIC.
> Without selecting SYSFS, the SRIOV feature will fail on VM on Hyper-V and
> Azure. The first version of this patch should be used.
> 
> @Stephen Hemminger how do you think?
> 
> Thanks,
> - Haiyang


Hi Stephen,

Please comment on this patch or v1.
v1:  https://lore.kernel.org/lkml/69c25bc3-da00-2758-92ee-13c82b51fc45@xxxxxxxxxxxxx/


thanks.
-- 
~Randy