Attempting to start a domain with USB hostdevs but no USB controllers fails with the rather cryptic error libxl: error: libxl_qmp.c:287:qmp_handle_error_response: received an error message from QMP server: Bus 'xenusb-0.0' not found This can be fixed by creating default USB controllers. When no USB controllers are defined, create the number of 8 port controllers necessary to accommodate the number of defined USB devices. Note that USB controllers are already created as needed in the domainAttachDevice code path. E.g. a USB controller will be created, if necessary, when attaching a USB device with 'virsh attach-device dom usbdev.xml'. Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; --- V1 here https://www.redhat.com/archives/libvir-list/2017-April/msg00965.html While further testing of V1 found a libvirtd segfault due to incorrectly using virDomainControllerInsertPreAlloced instead of virDomainControllerInsert. src/libxl/libxl_conf.c | 82 +++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 71 insertions(+), 11 deletions(-) diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c index 56bc09719..cdf6ec9f3 100644 --- a/src/libxl/libxl_conf.c +++ b/src/libxl/libxl_conf.c @@ -1822,34 +1822,94 @@ libxlMakeUSBController(virDomainControllerDefPtr controller, } static int +libxlMakeDefaultUSBControllers(virDomainDefPtr def, + libxl_domain_config *d_config) +{ + virDomainControllerDefPtr l_controller = NULL; + libxl_device_usbctrl *x_controllers = NULL; + size_t nusbdevs = 0; + size_t ncontrollers; + size_t i; + + for (i = 0; i < def->nhostdevs; i++) { + if (def->hostdevs[i]->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS && + def->hostdevs[i]->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB) + nusbdevs++; + } + + /* No controllers needed if there are no USB devs */ + if (nusbdevs == 0) + return 0; + + /* Create USB controllers with 8 ports */ + ncontrollers = VIR_DIV_UP(nusbdevs, 8); + if (VIR_ALLOC_N(x_controllers, ncontrollers) < 0) + return -1; + + for (i = 0; i < ncontrollers; i++) { + if (!(l_controller = virDomainControllerDefNew(VIR_DOMAIN_CONTROLLER_TYPE_USB))) + goto error; + + l_controller->model = VIR_DOMAIN_CONTROLLER_MODEL_USB_QUSB2; + l_controller->idx = i; + l_controller->opts.usbopts.ports = 8; + + libxl_device_usbctrl_init(&x_controllers[i]); + + if (libxlMakeUSBController(l_controller, &x_controllers[i]) < 0) + goto error; + + if (virDomainControllerInsert(def, l_controller) < 0) + goto error; + + l_controller = NULL; + } + + d_config->usbctrls = x_controllers; + d_config->num_usbctrls = ncontrollers; + return 0; + + error: + virDomainControllerDefFree(l_controller); + for (i = 0; i < ncontrollers; i++) + libxl_device_usbctrl_dispose(&x_controllers[i]); + VIR_FREE(x_controllers); + return -1; +} + +static int libxlMakeUSBControllerList(virDomainDefPtr def, libxl_domain_config *d_config) { virDomainControllerDefPtr *l_controllers = def->controllers; size_t ncontrollers = def->ncontrollers; size_t nusbctrls = 0; libxl_device_usbctrl *x_usbctrls; - size_t i; - - if (ncontrollers == 0) - return 0; - - if (VIR_ALLOC_N(x_usbctrls, ncontrollers) < 0) - return -1; + size_t i, j; for (i = 0; i < ncontrollers; i++) { + if (l_controllers[i]->type == VIR_DOMAIN_CONTROLLER_TYPE_USB) + nusbctrls++; + } + + if (nusbctrls == 0) + return libxlMakeDefaultUSBControllers(def, d_config); + + if (VIR_ALLOC_N(x_usbctrls, nusbctrls) < 0) + return -1; + + for (i = 0, j = 0; i < ncontrollers && j < nusbctrls; i++) { if (l_controllers[i]->type != VIR_DOMAIN_CONTROLLER_TYPE_USB) continue; - libxl_device_usbctrl_init(&x_usbctrls[nusbctrls]); + libxl_device_usbctrl_init(&x_usbctrls[j]); if (libxlMakeUSBController(l_controllers[i], - &x_usbctrls[nusbctrls]) < 0) + &x_usbctrls[j]) < 0) goto error; - nusbctrls++; + j++; } - VIR_SHRINK_N(x_usbctrls, ncontrollers, ncontrollers - nusbctrls); d_config->usbctrls = x_usbctrls; d_config->num_usbctrls = nusbctrls;

On Fri, 2017-05-05 at 15:48 -0600, Jim Fehlig wrote: > Attempting to start a domain with USB hostdevs but no USB controllers > fails with the rather cryptic error > > libxl: error: libxl_qmp.c:287:qmp_handle_error_response: received an > error message from QMP server: Bus 'xenusb-0.0' not found > > This can be fixed by creating default USB controllers. When no USB > controllers are defined, create the number of 8 port controllers > necessary to accommodate the number of defined USB devices. > > Note that USB controllers are already created as needed in the > domainAttachDevice code path. E.g. a USB controller will be created, > if necessary, when attaching a USB device with > 'virsh attach-device dom usbdev.xml'. > > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > > V1 here > > https://www.redhat.com/archives/libvir-list/2017-April/msg00965.html > > While further testing of V1 found a libvirtd segfault due to > incorrectly using virDomainControllerInsertPreAlloced instead of > virDomainControllerInsert. > > src/libxl/libxl_conf.c | 82 +++++++++++++++++++++++++++++++++++++++++++------- > 1 file changed, 71 insertions(+), 11 deletions(-) > > diff --git a/src/libxl/libxl_conf.c b/src/libxl/libxl_conf.c > index 56bc09719..cdf6ec9f3 100644 > --- a/src/libxl/libxl_conf.c > +++ b/src/libxl/libxl_conf.c > @@ -1822,34 +1822,94 @@ libxlMakeUSBController(virDomainControllerDefPtr controller, > } > > static int > +libxlMakeDefaultUSBControllers(virDomainDefPtr def, > + libxl_domain_config *d_config) > +{ > + virDomainControllerDefPtr l_controller = NULL; > + libxl_device_usbctrl *x_controllers = NULL; > + size_t nusbdevs = 0; > + size_t ncontrollers; > + size_t i; > + > + for (i = 0; i < def->nhostdevs; i++) { > + if (def->hostdevs[i]->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS && > + def->hostdevs[i]->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB) > + nusbdevs++; > + } > + > + /* No controllers needed if there are no USB devs */ > + if (nusbdevs == 0) > + return 0; > + > + /* Create USB controllers with 8 ports */ > + ncontrollers = VIR_DIV_UP(nusbdevs, 8); > + if (VIR_ALLOC_N(x_controllers, ncontrollers) < 0) > + return -1; > + > + for (i = 0; i < ncontrollers; i++) { > + if (!(l_controller = virDomainControllerDefNew(VIR_DOMAIN_CONTROLLER_TYPE_USB))) > + goto error; > + > + l_controller->model = VIR_DOMAIN_CONTROLLER_MODEL_USB_QUSB2; > + l_controller->idx = i; > + l_controller->opts.usbopts.ports = 8; > + > + libxl_device_usbctrl_init(&x_controllers[i]); > + > + if (libxlMakeUSBController(l_controller, &x_controllers[i]) < 0) > + goto error; > + > + if (virDomainControllerInsert(def, l_controller) < 0) > + goto error; > + > + l_controller = NULL; > + } > + > + d_config->usbctrls = x_controllers; > + d_config->num_usbctrls = ncontrollers; > + return 0; > + > + error: > + virDomainControllerDefFree(l_controller); > + for (i = 0; i < ncontrollers; i++) > + libxl_device_usbctrl_dispose(&x_controllers[i]); > + VIR_FREE(x_controllers); > + return -1; > +} > + > +static int > libxlMakeUSBControllerList(virDomainDefPtr def, libxl_domain_config *d_config) > { > virDomainControllerDefPtr *l_controllers = def->controllers; > size_t ncontrollers = def->ncontrollers; > size_t nusbctrls = 0; > libxl_device_usbctrl *x_usbctrls; > - size_t i; > - > - if (ncontrollers == 0) > - return 0; > - > - if (VIR_ALLOC_N(x_usbctrls, ncontrollers) < 0) > - return -1; > + size_t i, j; > > for (i = 0; i < ncontrollers; i++) { > + if (l_controllers[i]->type == VIR_DOMAIN_CONTROLLER_TYPE_USB) > + nusbctrls++; > + } > + > + if (nusbctrls == 0) > + return libxlMakeDefaultUSBControllers(def, d_config); > + > + if (VIR_ALLOC_N(x_usbctrls, nusbctrls) < 0) > + return -1; > + > + for (i = 0, j = 0; i < ncontrollers && j < nusbctrls; i++) { > if (l_controllers[i]->type != VIR_DOMAIN_CONTROLLER_TYPE_USB) > continue; > > - libxl_device_usbctrl_init(&x_usbctrls[nusbctrls]); > + libxl_device_usbctrl_init(&x_usbctrls[j]); > > if (libxlMakeUSBController(l_controllers[i], > - &x_usbctrls[nusbctrls]) < 0) > + &x_usbctrls[j]) < 0) > goto error; > > - nusbctrls++; > + j++; > } > > - VIR_SHRINK_N(x_usbctrls, ncontrollers, ncontrollers - nusbctrls); > d_config->usbctrls = x_usbctrls; > d_config->num_usbctrls = nusbctrls; > ACK