On 7/8/19 8:05 AM, Stephen Hemminger wrote: > On Sun, 7 Jul 2019 10:46:22 -0700 > Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > >> 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? > > Haiyang is right, accelerated networking won't work if slot is not recorded. > > So the original patch (to depend on SYSFS) or using "select SYSFS" is > are necessary. Thanks, I'll resend that one with the corrected Fixes: tag. > The whole thing is a bit of "angels dancing on the head of a pin" because > there is no good reason to build kernel without SYSFS in real world. > It would just be looking for trouble. As far as I can tell it is all > about getting "make randconfig" to work in more cases. You could submit a patch to remove the SYSFS kconfig entry. :) cheers. -- ~Randy