On Tue, Sep 15, 2026 at 8:31 PM Zhu Yanjun <[email protected]> wrote: > 在 2026/7/28 15:09, David Matlack 写道:
> > CONFIG_64BIT is now required to enable CONFIG_PCI_LIVEUPDATE so that the > > domain and bdf can be guaranteed to fit in an unsigned long and be used > > as the xarray key. > > diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig > > index 3781e2b5f095..8af20f558086 100644 > > --- a/drivers/pci/Kconfig > > +++ b/drivers/pci/Kconfig > > @@ -273,7 +273,7 @@ config VGA_ARB_MAX_GPUS > > > > config PCI_LIVEUPDATE > > bool "PCI Live Update Support" > > - depends on PCI && LIVEUPDATE > > + depends on PCI && LIVEUPDATE && 64BIT > > One question about adding 64BIT to the dependency: > > As I understand it, enabling CONFIG_64BIT essentially means that we are > building a 64-bit kernel, and a 32-bit architecture cannot normally > enable CONFIG_64BIT. > > If that is the case, would depends on 64BIT be necessary here? Or is PCI > Live Update already inherently restricted to 64-bit architectures by the > existing LIVEUPDATE/architecture configuration, so that this dependency > would be redundant? > > If this problem has already discussed, I am very sorry about this. The necessity is that the PCI core needs to store more than 32-bits in the unsigned long xarray key (see the snippet above). The dependency on CONFIG_64BIT ensures that unsigned long is big enough. We could probably remove the dependency but I would rather wait until someone with a 32-bit build has a real use-case for using PCI_LIVEUPDATE before putting any effort into it.
