Re: [PATCH v2 5/9] qemu: Deny all but VFIO PCI backends in hostdev prepare phase

On Mon, Apr 24, 2023 at 12:41:44PM +0200, Michal Privoznik wrote: > We used to support KVM and VFIO style of PCI assignment. The > former was dropped in v5.7.0-rc1~103 and thus we only support > VFIO. All other backends lead to an error (see > qemuBuildPCIHostdevDevProps(), or qemuBuildPCIHostdevDevStr() as > it used to be called in the era of aforementioned commit). > > Might as well report the error in prepare phase and save hassle > of proceeding with device preparation (e.g. in case of hotplug > overriding the device's driver, setting seclabels, etc.). > > Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; > --- > src/qemu/qemu_domain.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c > index 58cd3dd710..72f36c807b 100644 > --- a/src/qemu/qemu_domain.c > +++ b/src/qemu/qemu_domain.c > @@ -11326,12 +11326,11 @@ > qemuDomainPrepareHostdevPCI(virDomainHostdevDef *hostdev, >         break; > >     case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_KVM: > -        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", > -                       _("host doesn't support legacy PCI > passthrough")); > -        return false; > - >     case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_XEN: >     case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_TYPE_LAST: > +        virReportError(VIR_ERR_INTERNAL_ERROR, > +                       _("invalid PCI passthrough type '%1$s'"), > +                       > virDomainHostdevSubsysPCIBackendTypeToString(*backend)); This is a bit misleading as it is not "invalid", it's just unsupported, and on top of that you're changing it to internal error and I think it should still be CONFIG_UNSUPPORTED, at least for KVM and XEN.  _LAST (and possibly default:) is still an internal error of course.