Re: Usage of vfio-pci without KVM.

[Shlomo Pongratz]

Hi,
What can I as a user do to honor this requirement.
Are you suggesting that I should patch the QEMU code as it is not
supported out of the box?

Thank you.

S.P.

On Tue, Sep 12, 2023 at 3:58 PM Alex Williamson
<alex.williamson@redhat.com> wrote:
>
> On Tue, 12 Sep 2023 14:47:41 +0200
> Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>
> > Cc'ing VFIO maintainers.
> >
> > On 12/9/23 14:39, Shlomo Pongratz wrote:
> > > Hi,
> > > I'm running qemu-system-aarch64 (QEMU emulator version 7.0.93) on
> > > Ubuntu 20.04.4 LTS i with Intel's i7.
> > > I'm trying to pass a Samsung NVME device using vfio-pci. I detached
> > > the device from the nvme driver and attached it to the vfio-pci.
> > > Using lspci I can see "Kernel driver in use: vfio-pci"
> > > In QEMU script I've written "-device vfio-pci,host=0000:03:00.0" where
> > > 0000:03:00.0 is the device PCI address.
> > > I get the error
> > > qemu-system-aarch64: -device vfio-pci,host=0000:03:00.0: VFIO_MAP_DMA
> > > failed: Invalid argument
> > > qemu-system-aarch64: -device vfio-pci,host=0000:03:00.0: vfio
> > > 0000:03:00.0: failed to setup container for group 15: memory listener
> > > initialization failed: Region mach-virt.ram:
> > > vfio_dma_map(0x55855c75bf00, 0x40000000, 0x100000000, 0x7f5197e00000)
> > > = -22 (Invalid argument
> > >
> > > My question is vfio-pci is supported with cross architecture?
>
> It does, but reserved address ranges need to be honored.  x86 has a
> reserved range at 0xfee00000 for MSI mapping, so the VM address space
> needs to be such that it avoids trying to place mappings there.  Thanks,
>
> Alex
>