Re: [Qemu-devel] [PATCH v6 0/5] Connect a PCIe host and graphics support to RISC-V

[Alistair Francis]

On Wed, Oct 31, 2018 at 7:51 AM Andrea Bolognani <address@hidden> wrote:
>
> On Tue, 2018-10-30 at 22:17 +0000, Alistair Francis wrote:
> > V6:
> >  - Fix the interrupt issue for the GPEX device
>
> I gave this a spin.
>
> With the pcie.0 <- pcie-root-port <- virtio-net-pci setup I get
>
>   qemu-system-riscv64: -device pcie-root-port,port=0x8,chassis=1,\
>   id=pci.1,bus=pcie.0,multifunction=on,addr=0x1: MSI-X is not \
>   supported by interrupt controller
>
> just like last time, which as I mentioned is a problem for libvirt
> because we follow the recommendations outlined in qemu/docs/pcie.txt
> and never plug devices into pcie.0 directly.

At the moment we can't support MSI, the interrupt controller doesn't
support MSI.

>
> Even after working around that issue by manually placing the device
> at 0000:00:01.0, it still doesn't work: I see
>
>   pci 0000:00:01.0: BAR 6: assigned [mem 0x00000000-0x0003ffff pref]
>   pci 0000:00:01.0: BAR 4: assigned [mem 0x00040000-0x00043fff 64bit pref]
>   pci 0000:00:01.0: BAR 0: no space for [io  size 0x0020]
>   pci 0000:00:01.0: BAR 0: failed to assign [io  size 0x0020]
>   ...
>   virtio_net virtio3: virtio: device uses modern interface but does not have 
> VIRTIO_F_VERSION_1
>   virtio_net: probe of virtio3 failed with error -22

Yep, someone else pointed out a problem as well. I have made some
changes [1] but I still can't get the BAR to line up.

>
> in dmesg and, while the device shows up in the output of lspci(8),
> it's nowhere to be seen when running 'ip addr' and friends.
>
> Let me know if you need me to try anything else :)

Any ideas on how to debug the confusing memory mappings or
non-existent interrupts would be helpful :)

1: https://github.com/alistair23/qemu/tree/mainline/alistair/sifive_pcie.next

Alistair

>
> --
> Andrea Bolognani / Red Hat / Virtualization
>