Re: [libvirt] [PATCH 4/5] qemu: Check if PCI passhtrough is available in the host when starting

On Fri, Sep 20, 2013 at 11:06:59AM +0200, Peter Krempa wrote: > Check the presence of the selected PCI passthrough option when starting > a VM. > --- > src/qemu/qemu_process.c | 41 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 41 insertions(+) > > diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c > index dd16f6c..e36ab99 100644 > --- a/src/qemu/qemu_process.c > +++ b/src/qemu/qemu_process.c > @@ -3481,6 +3481,8 @@ int qemuProcessStart(virConnectPtr conn, > unsigned int stop_flags; > virQEMUDriverConfigPtr cfg; > virCapsPtr caps = NULL; > + int supportsPassthroughKVM = -1; > + int supportsPassthroughVFIO = -1; > > /* Okay, these are just internal flags, > * but doesn't hurt to check */ > @@ -3713,6 +3715,45 @@ int qemuProcessStart(virConnectPtr conn, > goto cleanup; > } > > + /* assign defaults for hostdev passthrough */ > + for (i = 0; i < vm->def->nhostdevs; i++) { > + virDomainHostdevDefPtr hostdev = vm->def->hostdevs[i]; > + > + if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS && > + hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI) { > + int *backend = &hostdev->source.subsys.u.pci.backend; > + > + /* cache host state of passthrough support */ > + if (supportsPassthroughKVM == -1 || supportsPassthroughVFIO == -1) { > + supportsPassthroughKVM = qemuHostdevHostSupportsPassthroughLegacy(); > + supportsPassthroughVFIO = qemuHostdevHostSupportsPassthroughVFIO(); > + } > + > + switch ((virDomainHostdevSubsysPciBackendType) *backend) { > + case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO: > + if (!supportsPassthroughVFIO) { > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", > + _("host doesn't support VFIO PCI passthrough")); > + goto cleanup; > + } > + break; > + > + case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_DEFAULT: > + case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_KVM: > + if (!supportsPassthroughKVM) { > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", > + _("host doesn't support legacy PCI passthrough")); > + goto cleanup; > + } > + > + break; > + > + case VIR_DOMAIN_HOSTDEV_PCI_BACKEND_TYPE_LAST: > + break; > + } > + } > + } It seems like the body of this loop ought to be shared with the hotplug code, in a helper function, so we don't have so much extra code in this start method

Daniel