Re: [PATCH v2 7/8] hw/arm/virt: Fix devicetree warnings about the virtio-iommu node

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

On Tue, Sep 27, 2022 at 04:35:25PM +0200, Eric Auger wrote:
> >> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> >> index 2de16f6324..5e16d54bbb 100644
> >> --- a/hw/arm/virt.c
> >> +++ b/hw/arm/virt.c
> >> @@ -1372,14 +1372,15 @@ static void create_smmu(const VirtMachineState *vms,
> >>
> >>  static void create_virtio_iommu_dt_bindings(VirtMachineState *vms)
> >>  {
> >> -    const char compat[] = "virtio,pci-iommu";
> >> +    const char compat[] = "virtio,pci-iommu\0pci1af4,1057";
> >>      uint16_t bdf = vms->virtio_iommu_bdf;
> > 
> > PCI_DEVICE_ID_VIRTIO_IOMMU is listed in include/hw/pci/pci.h
> > as 0x1014, so where does 1057 come from? (This is a hex value,
> > right?)
> the virtio spec states:
> The PCI Device ID is calculated by adding 0x1040 to the Virtio Device ID
> (this IOMMU device ID is 0d23 = 0x17 for the virtio-iommu device, also
> found in include/uapi/linux/virtio_ids.h) so 0x1057 above looks correct
> 
> note that in docs/specs/pci-ids.txt there are a bunch of other device
> ids not documented (virtio-mem, pmem)
> 
> What I don't get anymore is the device id in qemu include/hw/pci/pci.h

Yes 0x1057 is the right device ID, and it matches what the
virtio-iommu-pci device gets in hw/virtio/virtio-pci.c:1691.
The wrong 0x1014 value set by hw/virtio/virtio-iommu-pci.c:78 gets
overwritten since virtio-iommu is modern only. I can send a patch to
remove it.

Peter, do you mind taking this patch as well, or should I resend it?
I can't decide what to do about the other issues in this series, we may
have to live with some warnings, but this one should be OK.

Thanks,
Jean

[1] https://lore.kernel.org/qemu-devel/aec4e9d1-b70e-2e8d-6503-b3e550c6d5ea@redhat.com/