On Mon, Dec 1, 2025 at 1:46 PM Yanjun.Zhu <[email protected]> wrote: > > > On 12/1/25 9:44 AM, Pasha Tatashin wrote: > > On Mon, Dec 1, 2025 at 12:36 PM David Matlack <[email protected]> wrote: > >> On 2025-12-01 05:32 PM, David Matlack wrote: > >>> On 2025-12-01 09:16 AM, Zhu Yanjun wrote: > >>>> 在 2025/12/1 9:10, David Matlack 写道: > >>>>> On Mon, Dec 1, 2025 at 7:49 AM Zhu Yanjun <[email protected]> wrote: > >>>>>> 在 2025/11/27 20:56, Zhu Yanjun 写道: > >>>>>>> Hi, David > >>>>>>> > >>>>>>> ERROR: modpost: "liveupdate_register_file_handler" [drivers/vfio/pci/ > >>>>>>> vfio-pci-core.ko] undefined! > >>>>>>> > >>>>>>> ERROR: modpost: "vfio_pci_ops" [drivers/vfio/pci/vfio-pci-core.ko] > >>>>>>> undefined! > >>>>>>> ERROR: modpost: "liveupdate_enabled" > >>>>>>> [drivers/vfio/pci/vfio-pci-core.ko] > >>>>>>> undefined! > >>>>>>> ERROR: modpost: "liveupdate_unregister_file_handler" > >>>>>>> [drivers/vfio/pci/ > >>>>>>> vfio-pci-core.ko] undefined! > >>>>>>> ERROR: modpost: "vfio_device_fops" [drivers/vfio/pci/vfio-pci-core.ko] > >>>>>>> undefined! > >>>>>>> ERROR: modpost: "vfio_pci_is_intel_display" > >>>>>>> [drivers/vfio/pci/vfio-pci- > >>>>>>> core.ko] undefined! > >>>>>>> ERROR: modpost: "vfio_pci_liveupdate_init" [drivers/vfio/pci/vfio- > >>>>>>> pci.ko] undefined! > >>>>>>> ERROR: modpost: "vfio_pci_liveupdate_cleanup" [drivers/vfio/pci/vfio- > >>>>>>> pci.ko] undefined! > >>>>>>> make[4]: *** [scripts/Makefile.modpost:147: Module.symvers] Error 1 > >>>>>>> make[3]: *** [Makefile:1960: modpost] Error 2 > >>>>>>> > >>>>>>> After I git clone the source code from the link https://github.com/ > >>>>>>> dmatlack/linux/tree/liveupdate/vfio/cdev/v1, > >>>>>>> > >>>>>>> I found the above errors when I built the source code. > >>>>>>> > >>>>>>> Perhaps the above errors can be solved by EXPORT_SYMBOL. > >>>>>>> > >>>>>>> But I am not sure if a better solution can solve the above problems > >>>>>>> or not. > >>>>>> I reviewed this patch series in detail. If I’m understanding it > >>>>>> correctly, there appears to be a cyclic dependency issue. Specifically, > >>>>>> some functions in kernel module A depend on kernel module B, while at > >>>>>> the same time certain functions in module B depend on module A. > >>>>>> > >>>>>> I’m not entirely sure whether this constitutes a real problem or if > >>>>>> it’s > >>>>>> intentional design. > >>>>> Thanks for your report. Can you share the .config file you used to > >>>>> generate these errors? > >>>> > >>>> IIRC, I used FC 42 default config. Perhaps you can make tests with it. If > >>>> this problem can not be reproduced, I will share my config with you. > >>>> > >>> What does "FC 42 default config" mean? > >>> > >>> Either way I was able to reproduce the errors you posted above by > >>> changing CONFIG_VFIO_PCI{_CORE} from "y" to "m". > >>> > >>> To unblock building and testing this series you can change these configs > >>> from "m" to "y", or the following patch (which fixed things for me): > >> Oops, sorry, something went wrong when I posted that diff. Here's the > >> correct diff: > >> > >> diff --git a/drivers/vfio/pci/Makefile b/drivers/vfio/pci/Makefile > >> index 929df22c079b..c2cca16e99a8 100644 > >> --- a/drivers/vfio/pci/Makefile > >> +++ b/drivers/vfio/pci/Makefile > >> @@ -2,11 +2,11 @@ > >> > >> vfio-pci-core-y := vfio_pci_core.o vfio_pci_intrs.o vfio_pci_rdwr.o > >> vfio_pci_config.o > >> vfio-pci-core-$(CONFIG_VFIO_PCI_ZDEV_KVM) += vfio_pci_zdev.o > >> -vfio-pci-core-$(CONFIG_LIVEUPDATE) += vfio_pci_liveupdate.o > >> obj-$(CONFIG_VFIO_PCI_CORE) += vfio-pci-core.o > >> > >> vfio-pci-y := vfio_pci.o > >> vfio-pci-$(CONFIG_VFIO_PCI_IGD) += vfio_pci_igd.o > >> +vfio-pci-$(CONFIG_LIVEUPDATE) += vfio_pci_liveupdate.o > >> obj-$(CONFIG_VFIO_PCI) += vfio-pci.o > >> > >> obj-$(CONFIG_MLX5_VFIO_PCI) += mlx5/ > >> diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c > >> index c5b5eb509474..b9805861763a 100644 > >> --- a/drivers/vfio/vfio_main.c > >> +++ b/drivers/vfio/vfio_main.c > >> @@ -1386,6 +1386,7 @@ const struct file_operations vfio_device_fops = { > >> .show_fdinfo = vfio_device_show_fdinfo, > >> #endif > >> }; > >> +EXPORT_SYMBOL_GPL(vfio_device_fops); > >> > >> /** > >> * vfio_file_is_valid - True if the file is valid vfio file > >> diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c > >> index 69298d82f404..c7a0c9c3b6a8 100644 > >> --- a/kernel/liveupdate/luo_core.c > >> +++ b/kernel/liveupdate/luo_core.c > >> @@ -256,6 +256,7 @@ bool liveupdate_enabled(void) > >> { > >> return luo_global.enabled; > >> } > >> +EXPORT_SYMBOL_GPL(liveupdate_enabled); > >> > >> /** > >> * DOC: LUO ioctl Interface > >> diff --git a/kernel/liveupdate/luo_file.c b/kernel/liveupdate/luo_file.c > >> index fca3806dae28..9baa88966f04 100644 > >> --- a/kernel/liveupdate/luo_file.c > >> +++ b/kernel/liveupdate/luo_file.c > >> @@ -868,6 +868,7 @@ int liveupdate_register_file_handler(struct > >> liveupdate_file_handler *fh) > >> luo_session_resume(); > >> return err; > >> } > >> +EXPORT_SYMBOL_GPL(liveupdate_register_file_handler); > >> > >> /** > >> * liveupdate_unregister_file_handler - Unregister a liveupdate file > >> handler > >> @@ -913,3 +914,4 @@ int liveupdate_unregister_file_handler(struct > >> liveupdate_file_handler *fh) > >> liveupdate_test_register(fh); > >> return err; > >> } > >> +EXPORT_SYMBOL_GPL(liveupdate_unregister_file_handler); > > > Sure. Exactly. The above is the same with my solution. But after that > EXPORT_SYMBOL_GPL, a cyclic dependency issue will occur.
Did see the change to drivers/vfio/pci/Makefile? That fixes the circular dependency between vfio-pci and vfio-pci-core that I created in this series.
