[libvirt] [PATCH v2 4/5] qemu: Allow hotplug of vhost-scsi device
Eric Farman
farman at linux.vnet.ibm.com
Sat Aug 20 15:52:44 UTC 2016
Adjust the device string that is built for vhost-scsi devices so that it
can be invoked from hotplug.
>From the QEMU command line, the file descriptors are expect to be numeric only.
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 at linux.vnet.ibm.com>
---
src/conf/domain_conf.c | 6 ++
src/qemu/qemu_hotplug.c | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 154 insertions(+)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 636e81a..e5126b5 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -13669,6 +13669,12 @@ virDomainHostdevMatchSubsys(virDomainHostdevDefPtr a,
return virDomainHostdevMatchSubsysSCSIiSCSI(a, b);
else
return virDomainHostdevMatchSubsysSCSIHost(a, b);
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST:
+ if (a->source.subsys.u.host.protocol !=
+ b->source.subsys.u.host.protocol)
+ return 0;
+ if (STREQ(a->source.subsys.u.host.wwpn, b->source.subsys.u.host.wwpn))
+ return 1;
}
return 0;
}
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 7a6d285..feba545 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -2165,6 +2165,119 @@ qemuDomainAttachHostSCSIDevice(virConnectPtr conn,
goto cleanup;
}
+static int
+qemuDomainAttachHostSCSIHostDevice(virQEMUDriverPtr driver,
+ virDomainObjPtr vm,
+ virDomainHostdevDefPtr hostdev)
+{
+ int ret = -1;
+ qemuDomainObjPrivatePtr priv = vm->privateData;
+ virDomainCCWAddressSetPtr ccwaddrs = NULL;
+ char *vhostfdName = NULL;
+ int vhostfd = -1;
+ size_t vhostfdSize = 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 (qemuSetupHostdevCgroup(vm, hostdev) < 0)
+ goto cleanup;
+ teardowncgroup = true;
+
+ if (virSecurityManagerSetHostdevLabel(driver->securityManager,
+ vm->def, hostdev, NULL) < 0)
+ goto cleanup;
+ teardownlabel = true;
+
+ if (virSCSIOpenVhost(&vhostfd, &vhostfdSize) < 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 (virDomainPCIAddressEnsureAddr(priv->pciaddrs, &hostdev->info) < 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;
+
+ qemuDomainObjEnterMonitor(driver, vm);
+
+ if (hostdev->source.subsys.u.host.protocol == VIR_DOMAIN_HOSTDEV_HOST_PROTOCOL_TYPE_VHOST) {
+ if (!(devstr = qemuBuildHostHostdevDevStr(vm->def,
+ hostdev,
+ priv->qemuCaps,
+ vhostfdName,
+ vhostfdSize)))
+ goto exit_monitor;
+
+ if ((ret = qemuMonitorAddDeviceWithFd(priv->mon,
+ devstr,
+ vhostfd,
+ vhostfdName)) < 0) {
+ goto exit_monitor;
+ }
+ }
+
+ if (qemuDomainObjExitMonitor(driver, vm) < 0)
+ goto cleanup;
+
+ virDomainAuditHostdev(vm, hostdev, "attach", true);
+
+ if (VIR_REALLOC_N(vm->def->hostdevs, vm->def->nhostdevs + 1) < 0)
+ goto cleanup;
+
+ vm->def->hostdevs[vm->def->nhostdevs++] = hostdev;
+
+ virDomainCCWAddressSetFree(ccwaddrs);
+
+ VIR_FORCE_CLOSE(vhostfd);
+ VIR_FREE(vhostfdName);
+ VIR_FREE(devstr);
+ return 0;
+
+ exit_monitor:
+ ignore_value(qemuDomainObjExitMonitor(driver, vm));
+
+ cleanup:
+ 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);
+
+ VIR_FORCE_CLOSE(vhostfd);
+ VIR_FREE(vhostfdName);
+ VIR_FREE(devstr);
+ return ret;
+}
+
int
qemuDomainAttachHostDevice(virConnectPtr conn,
@@ -2198,6 +2311,11 @@ qemuDomainAttachHostDevice(virConnectPtr conn,
goto error;
break;
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST:
+ if (qemuDomainAttachHostSCSIHostDevice(driver, vm, hostdev) < 0)
+ goto error;
+ break;
+
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("hostdev subsys type '%s' not supported"),
@@ -3965,6 +4083,31 @@ qemuDomainDetachHostSCSIDevice(virQEMUDriverPtr driver,
}
static int
+qemuDomainDetachHostSCSIHostDevice(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)
@@ -3986,6 +4129,9 @@ qemuDomainDetachThisHostDevice(virQEMUDriverPtr driver,
case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI:
ret = qemuDomainDetachHostSCSIDevice(driver, vm, detach);
break;
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST:
+ ret = qemuDomainDetachHostSCSIHostDevice(driver, vm, detach);
+ break;
default:
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("hostdev subsys type '%s' not supported"),
@@ -4063,6 +4209,8 @@ int qemuDomainDetachHostDevice(virQEMUDriverPtr driver,
}
break;
}
+ case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST:
+ break;
default:
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unexpected hostdev type %d"), subsys->type);
--
1.9.1
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