Re: [Qemu-devel] [PATCH v5 0/5] Connect a PCIe host and graphics support to RISC-V

[Andrea Bolognani]

On Thu, 2018-10-11 at 12:45 +0100, Richard W.M. Jones wrote:
> On Thu, Oct 11, 2018 at 09:01:14AM +0100, Richard W.M. Jones wrote:
> > Here are the settings we currently do NOT have in my RV kernel:
> > 
> > CONFIG_HOTPLUG_PCI_PCIE=y
> > CONFIG_HOTPLUG_PCI=y
> > CONFIG_MEDIA_PCI_SUPPORT=y
> > CONFIG_PCI_ATS=y
> > CONFIG_PCI_DEBUG=y
> > CONFIG_PCIEAER=y
> > CONFIG_PCIEASPM_DEFAULT=y
> > CONFIG_PCIEASPM=y
> > CONFIG_PCI_ECAM=y
> > CONFIG_PCIE_MICROSEMI=y
> > CONFIG_PCI_ENDPOINT=y
> > CONFIG_PCIEPORTBUS=y
> > CONFIG_PCI_HOST_COMMON=y
> > CONFIG_PCI_HOST_GENERIC=y
> > CONFIG_PCI_IOV=y
> > CONFIG_PCI_PASID=y
> > CONFIG_PCI_PRI=y
> > CONFIG_PCI_SW_SWITCHTEC=y
> > CONFIG_USB_BDC_PCI=y
> > 
> > If you're happy with it, I can add all of those.  If there are any
> > which shouldn't be added let me know.
> 
> I didn't see an answer but in any case I have tried to enable all of
> these.  The only settings which could not be enabled were:
> 
> CONFIG_MEDIA_PCI_SUPPORT=y
> CONFIG_PCI_ECAM=y
> CONFIG_PCI_HOST_COMMON=y
> CONFIG_PCI_HOST_GENERIC=y

I believe these last two are the ones we really miss. I could be
wrong though - as you know, I've made a few guesses that didn't
quite pan out already :)

> CONFIG_USB_BDC_PCI=y
> 
> Probably missing deps or missing arch support.  I didn't track them
> down yet, but note I'm still using kernel 4.15.
> 
>   https://github.com/rwmjones/fedora-riscv-kernel/commits/master

We talked about this on IRC a while ago: assuming my guess above
is correct, you would need to backport

  
https://github.com/torvalds/linux/commit/51bc085d6454214b02dba7a259ee1fdfe3ee8d9f

because that's the one that makes PCI_HOST_GENERIC available to
non-ARM architectures.

> In any case a new kernel/bbl has been built, available in the usual
> place:
> 
>   https://fedorapeople.org/groups/risc-v/disk-images/

I gave it a spin: it doesn't work :(

-- 
Andrea Bolognani / Red Hat / Virtualization