[libvirt] [PATCH v4 5/9] qemu: Allow hotplug of vhost-scsi device

Adjust the device string that is built for vhost-scsi devices so that it can be invoked from hotplug. However, for hotplug, the file descriptors are expected to begin with at least one alphabetic character else this error occurs: # virsh attach-device guest_0001 ~/vhost.xml error: Failed to attach device from /root/vhost.xml error: internal error: unable to execute QEMU command 'getfd': Parameter 'fdname' expects a name not starting with a digit We also close the file descriptor in this case, so that shutting down the guest cleans up the host cgroup entries and allows future guests to use vhost-scsi devices. (Otherwise the guest will silently end.) Signed-off-by: Eric Farman <farman(a)linux.vnet.ibm.com&gt; --- src/qemu/qemu_hotplug.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 164 insertions(+) diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 0508c67..02e248f 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2443,6 +2443,126 @@ qemuDomainAttachHostSCSIDevice(virConnectPtr conn, goto cleanup; } +static int +qemuDomainAttachSCSIVHostDevice(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainHostdevDefPtr hostdev) +{ + int ret = -1; + qemuDomainObjPrivatePtr priv = vm->privateData; + virErrorPtr orig_err; + virDomainDeviceDef dev = { VIR_DOMAIN_DEVICE_HOSTDEV, + { .hostdev = hostdev } }; + virDomainCCWAddressSetPtr ccwaddrs = NULL; + char *vhostfdName = NULL; + int vhostfd = -1; + char *devstr = NULL; + bool teardowncgroup = false; + bool teardownlabel = false; + bool releaseaddr = false; + + if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE_SCSI_GENERIC)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("SCSI passthrough is not supported by this version of qemu")); + goto cleanup; + } + + if (qemuHostdevPrepareSCSIVHostDevices(driver, vm->def->name, &hostdev, 1) < 0) { + virDomainHostdevSubsysSCSIVHostPtr hostsrc = &hostdev->source.subsys.u.scsi_host; + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Unable to prepare scsi_host hostdev: %s"), + hostsrc->wwpn); + goto cleanup; + } + + if (qemuSetupHostdevCgroup(vm, hostdev) < 0) + goto cleanup; + teardowncgroup = true; + + if (virSecurityManagerSetHostdevLabel(driver->securityManager, + vm->def, hostdev, NULL) < 0) + goto cleanup; + teardownlabel = true; + + if (virSCSIVHostOpenVhostSCSI(&vhostfd) < 0) + goto cleanup; + + if (virAsprintf(&vhostfdName, "vhostfd-%d", vhostfd) < 0) + goto cleanup; + + if (hostdev->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE) { + if (qemuDomainMachineIsS390CCW(vm->def) && + virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_VIRTIO_CCW)) + hostdev->info->type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW; + } + + if (hostdev->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE || + hostdev->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI) { + if (qemuDomainEnsurePCIAddress(vm, &dev) < 0) + goto cleanup; + } else if (hostdev->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW) { + if (!(ccwaddrs = qemuDomainCCWAddrSetCreateFromDomain(vm->def))) + goto cleanup; + if (virDomainCCWAddressAssign(hostdev->info, ccwaddrs, + !hostdev->info->addr.ccw.assigned) < 0) + goto cleanup; + } + releaseaddr = true; + + if (qemuAssignDeviceHostdevAlias(vm->def, &hostdev->info->alias, -1) < 0) + goto cleanup; + + if (!(devstr = qemuBuildSCSIVHostHostdevDevStr(vm->def, + hostdev, + priv->qemuCaps, + vhostfdName))) + goto cleanup; + + if (VIR_REALLOC_N(vm->def->hostdevs, vm->def->nhostdevs + 1) < 0) + goto cleanup; + + qemuDomainObjEnterMonitor(driver, vm); + + if (qemuMonitorAddDeviceWithFd(priv->mon, devstr, vhostfd, vhostfdName) < 0) + goto exit_monitor; + + if (qemuDomainObjExitMonitor(driver, vm) < 0) + goto audit; + + vm->def->hostdevs[vm->def->nhostdevs++] = hostdev; + ret = 0; + + audit: + virDomainAuditHostdev(vm, hostdev, "attach", (ret == 0)); + + cleanup: + virDomainCCWAddressSetFree(ccwaddrs); + + VIR_FORCE_CLOSE(vhostfd); + VIR_FREE(vhostfdName); + VIR_FREE(devstr); + return ret; + + exit_monitor: + orig_err = virSaveLastError(); + + if (teardowncgroup && qemuTeardownHostdevCgroup(vm, hostdev) < 0) + VIR_WARN("Unable to remove host device cgroup ACL on hotplug fail"); + if (teardownlabel && + virSecurityManagerRestoreHostdevLabel(driver->securityManager, + vm->def, hostdev, NULL) < 0) + VIR_WARN("Unable to restore host device labelling on hotplug fail"); + if (releaseaddr) + qemuDomainReleaseDeviceAddress(vm, hostdev->info, NULL); + + if (orig_err) { + virSetError(orig_err); + virFreeError(orig_err); + } + + goto audit; +} + int qemuDomainAttachHostDevice(virConnectPtr conn, @@ -2476,6 +2596,11 @@ qemuDomainAttachHostDevice(virConnectPtr conn, goto error; break; + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST: + if (qemuDomainAttachSCSIVHostDevice(driver, vm, hostdev) < 0) + goto error; + break; + default: virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("hostdev subsys type '%s' not supported"), @@ -3568,6 +3693,14 @@ qemuDomainRemoveSCSIHostDevice(virQEMUDriverPtr driver, qemuHostdevReAttachSCSIDevices(driver, vm->def->name, &hostdev, 1); } +static void +qemuDomainRemoveSCSIVHostDevice(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainHostdevDefPtr hostdev) +{ + qemuHostdevReAttachSCSIVHostDevices(driver, vm->def->name, &hostdev, 1); +} + static int qemuDomainRemoveHostDevice(virQEMUDriverPtr driver, virDomainObjPtr vm, @@ -3646,6 +3779,7 @@ qemuDomainRemoveHostDevice(virQEMUDriverPtr driver, qemuDomainRemoveSCSIHostDevice(driver, vm, hostdev); break; case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST: + qemuDomainRemoveSCSIVHostDevice(driver, vm, hostdev); break; case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_LAST: break; @@ -4496,6 +4630,31 @@ qemuDomainDetachHostSCSIDevice(virQEMUDriverPtr driver, } static int +qemuDomainDetachSCSIVHostDevice(virQEMUDriverPtr driver, + virDomainObjPtr vm, + virDomainHostdevDefPtr detach) +{ + qemuDomainObjPrivatePtr priv = vm->privateData; + int ret = -1; + + if (!detach->info->alias) { + virReportError(VIR_ERR_OPERATION_FAILED, + "%s", _("device cannot be detached without a device alias")); + return -1; + } + + qemuDomainMarkDeviceForRemoval(vm, detach->info); + + qemuDomainObjEnterMonitor(driver, vm); + ret = qemuMonitorDelDevice(priv->mon, detach->info->alias); + + if (qemuDomainObjExitMonitor(driver, vm) < 0) + return -1; + + return ret; +} + +static int qemuDomainDetachThisHostDevice(virQEMUDriverPtr driver, virDomainObjPtr vm, virDomainHostdevDefPtr detach) @@ -4517,6 +4676,9 @@ qemuDomainDetachThisHostDevice(virQEMUDriverPtr driver, case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI: ret = qemuDomainDetachHostSCSIDevice(driver, vm, detach); break; + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST: + ret = qemuDomainDetachSCSIVHostDevice(driver, vm, detach); + break; default: virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("hostdev subsys type '%s' not supported"), @@ -4594,6 +4756,8 @@ int qemuDomainDetachHostDevice(virQEMUDriverPtr driver, } break; } + case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI_HOST: + break; default: virReportError(VIR_ERR_INTERNAL_ERROR, _("unexpected hostdev type %d"), subsys->type); -- 1.9.1