Re: [PATCH v2 2/3] misc/pvpanic: add PCI driver

[Greg KH]

On Fri, Feb 12, 2021 at 11:17:05AM +0200, Mihai Carabas wrote:
> Add support for pvpanic PCI device added in qemu [1]. At probe time, obtain the
> address where to read/write pvpanic events and pass it to the generic handling
> code. Will follow the same logic as pvpanic MMIO device driver. At remove time,
> unmap base address and disable PCI device.
> 
> [1] https://github.com/qemu/qemu/commit/9df52f58e76e904fb141b10318362d718f470db2
> 
> Signed-off-by: Mihai Carabas <mihai.carabas@xxxxxxxxxx>
> ---
>  drivers/misc/pvpanic/Kconfig  |  8 +++++++
>  drivers/misc/pvpanic/Makefile |  2 ++
>  drivers/misc/pvpanic/pci.c    | 49 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 59 insertions(+)
>  create mode 100644 drivers/misc/pvpanic/pci.c
> 
> diff --git a/drivers/misc/pvpanic/Kconfig b/drivers/misc/pvpanic/Kconfig
> index 0dce6ef..ce8b93e 100644
> --- a/drivers/misc/pvpanic/Kconfig
> +++ b/drivers/misc/pvpanic/Kconfig
> @@ -10,3 +10,11 @@ config PVPANIC_MMIO
>  	  This driver provides support for the pvpanic device.  pvpanic is
>  	  a paravirtualized device provided by QEMU; it lets a virtual machine
>  	  (guest) communicate panic events to the host.
> +
> +config PVPANIC_PCI
> +	tristate "pvpanic PCI device support"
> +	depends on PCI && PVPANIC
> +	help
> +	  This driver provides support for the pvpanic device.  pvpanic is
> +	  a paravirtualized device provided by QEMU; it lets a virtual machine
> +	  (guest) communicate panic events to the host.
> diff --git a/drivers/misc/pvpanic/Makefile b/drivers/misc/pvpanic/Makefile
> index 9ea3355..1763450 100644
> --- a/drivers/misc/pvpanic/Makefile
> +++ b/drivers/misc/pvpanic/Makefile
> @@ -1,2 +1,4 @@
>  obj-$(CONFIG_PVPANIC_MMIO)	+= pvpanic-mmio.o
>  pvpanic-mmio-objs := pvpanic-common.o mmio.o
> +obj-$(CONFIG_PVPANIC_PCI)	+= pvpanic-pci.o
> +pvpanic-pci-objs := pvpanic-common.o pci.o

So you now have the pvpanic-common.o file linked into both modules at
the same time?  What happens if they are both loaded?

This feels really broken...

greg k-h