Re: [PATCH v2] tools/libxl: don't allow IOMMU usage with PoD

[Anthony PERARD]

On Thu, Feb 03, 2022 at 03:32:11PM +0100, Roger Pau Monne wrote:
>      if (d_config->c_info.type != LIBXL_DOMAIN_TYPE_PV &&
> -        d_config->num_pcidevs && pod_enabled) {
> +        d_config->c_info.passthrough != LIBXL_PASSTHROUGH_DISABLED &&
> +        pod_enabled) {
>          ret = ERROR_INVAL;
> -        LOGD(ERROR, domid,
> -             "PCI device assignment for HVM guest failed due to PoD 
> enabled");
> +        LOGD(ERROR, domid, "IOMMU not supported together with PoD");

I'm not sure that this new error message is going to be good enough to
point out configuration issue for the guest.

One is going to set 'pci=["foo"]' or 'dtdev=["bar"]', which will enable
passthrough. Then they may get en error about IOMMU or PoD.
Should we maybe write something like this instead?

   "IOMMU or device passthrough not supported together with PoD"

Thanks,

-- 
Anthony PERARD