[libvirt] [PATCH v3 05/10] qemu: Add vhost-scsi string for -device parameter

Eric Farman farman at linux.vnet.ibm.com
Mon Oct 31 14:08:14 UTC 2016


Open /dev/vhost-scsi, and record the resulting file descriptor, so that
the guest has access to the host device outside of the libvirt daemon.
Pass this information, along with data parsed from the XML file, to build
a device string for the qemu command line.  That device string will be
for either a vhost-scsi-ccw device in the case of an s390 machine, or
vhost-scsi-pci for any others.

Signed-off-by: Eric Farman <farman at linux.vnet.ibm.com>
---
 src/qemu/qemu_cgroup.c         | 32 +++++++++++++++++
 src/qemu/qemu_command.c        | 79 ++++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_command.h        |  5 +++
 src/qemu/qemu_domain_address.c | 10 ++++++
 src/qemu/qemu_hostdev.c        | 41 ++++++++++++++++++++++
 src/qemu/qemu_hostdev.h        |  8 +++++
 6 files changed, 175 insertions(+)

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index ee31d14..a22a1bf 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -277,6 +277,25 @@ qemuSetupHostSCSIDeviceCgroup(virSCSIDevicePtr dev ATTRIBUTE_UNUSED,
     return ret;
 }
 
+static int
+qemuSetupHostHostDeviceCgroup(virHostDevicePtr dev ATTRIBUTE_UNUSED,
+                              const char *path,
+                              void *opaque)
+{
+    virDomainObjPtr vm = opaque;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    int ret;
+
+    VIR_DEBUG("Process path '%s' for scsi_host device", path);
+
+    ret = virCgroupAllowDevicePath(priv->cgroup, path,
+                                   VIR_CGROUP_DEVICE_RW, false);
+
+    virDomainAuditCgroupPath(vm, priv->cgroup, "allow", path, "rw", ret == 0);
+
+    return ret;
+}
+
 int
 qemuSetupHostdevCgroup(virDomainObjPtr vm,
                        virDomainHostdevDefPtr dev)
@@ -286,9 +305,11 @@ qemuSetupHostdevCgroup(virDomainObjPtr vm,
     virDomainHostdevSubsysUSBPtr usbsrc = &dev->source.subsys.u.usb;
     virDomainHostdevSubsysPCIPtr pcisrc = &dev->source.subsys.u.pci;
     virDomainHostdevSubsysSCSIPtr scsisrc = &dev->source.subsys.u.scsi;
+    virDomainHostdevSubsysHostPtr hostsrc = &dev->source.subsys.u.host;
     virPCIDevicePtr pci = NULL;
     virUSBDevicePtr usb = NULL;
     virSCSIDevicePtr scsi = NULL;
+    virHostDevicePtr host = NULL;
     char *path = NULL;
 
     /* currently this only does something for PCI devices using vfio
@@ -377,6 +398,16 @@ qemuSetupHostdevCgroup(virDomainObjPtr vm,
         }
 
         case VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST: {
+            if (hostsrc->protocol ==
+                VIR_DOMAIN_HOSTDEV_SUBSYS_HOST_PROTOCOL_TYPE_VHOST) {
+                if ((host = virHostDeviceNew(hostsrc->wwpn)) == NULL)
+                    goto cleanup;
+
+                if (virHostDeviceFileIterate(host,
+                                             qemuSetupHostHostDeviceCgroup,
+                                             vm) < 0)
+                    goto cleanup;
+            }
             break;
         }
 
@@ -390,6 +421,7 @@ qemuSetupHostdevCgroup(virDomainObjPtr vm,
     virPCIDeviceFree(pci);
     virUSBDeviceFree(usb);
     virSCSIDeviceFree(scsi);
+    virHostDeviceFree(host);
     VIR_FREE(path);
     return ret;
 }
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index b68da3d..4e946ea 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4722,6 +4722,43 @@ qemuBuildSCSIiSCSIHostdevDrvStr(virDomainHostdevDefPtr dev)
 }
 
 char *
+qemuBuildHostHostdevDevStr(const virDomainDef *def,
+                           virDomainHostdevDefPtr dev,
+                           virQEMUCapsPtr qemuCaps,
+                           char *vhostfdName)
+{
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
+    virDomainHostdevSubsysHostPtr hostsrc = &dev->source.subsys.u.host;
+
+    if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_VHOST_SCSI)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("This QEMU doesn't support vhost-scsi devices"));
+        goto cleanup;
+    }
+
+    if (ARCH_IS_S390(def->os.arch))
+        virBufferAddLit(&buf, "vhost-scsi-ccw");
+    else
+        virBufferAddLit(&buf, "vhost-scsi-pci");
+
+    virBufferAsprintf(&buf, ",wwpn=%s", hostsrc->wwpn);
+    virBufferAsprintf(&buf, ",vhostfd=%s", vhostfdName);
+    virBufferAsprintf(&buf, ",id=%s", dev->info->alias);
+
+    if (qemuBuildDeviceAddressStr(&buf, def, dev->info, qemuCaps) < 0)
+        goto cleanup;
+
+    if (virBufferCheckError(&buf) < 0)
+        goto cleanup;
+
+    return virBufferContentAndReset(&buf);
+
+ cleanup:
+    virBufferFreeAndReset(&buf);
+    return NULL;
+}
+
+char *
 qemuBuildSCSIHostdevDrvStr(virDomainHostdevDefPtr dev)
 {
     virBuffer buf = VIR_BUFFER_INITIALIZER;
@@ -5202,6 +5239,48 @@ qemuBuildHostdevCommandLine(virCommandPtr cmd,
                 return -1;
             }
         }
+
+        /* SCSI_host */
+        if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
+            subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_HOST) {
+            if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_DEVICE_SCSI_GENERIC)) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                               _("SCSI passthrough is not supported by this "
+                                 "version of qemu"));
+                return -1;
+            }
+
+            if (hostdev->source.subsys.u.host.protocol ==
+                VIR_DOMAIN_HOSTDEV_SUBSYS_HOST_PROTOCOL_TYPE_VHOST) {
+                char *vhostfdName = NULL;
+                int vhostfd = -1;
+
+                if (virHostOpenVhostSCSI(&vhostfd) < 0)
+                    return -1;
+
+                if (virAsprintf(&vhostfdName, "%d", vhostfd) < 0) {
+                    VIR_FORCE_CLOSE(vhostfd);
+                    return -1;
+                }
+
+                virCommandPassFD(cmd, vhostfd,
+                                 VIR_COMMAND_PASS_FD_CLOSE_PARENT);
+
+                virCommandAddArg(cmd, "-device");
+                if (!(devstr = qemuBuildHostHostdevDevStr(def,
+                                                          hostdev,
+                                                          qemuCaps,
+                                                          vhostfdName))) {
+                    VIR_FREE(vhostfdName);
+                    VIR_FORCE_CLOSE(vhostfd);
+                    return -1;
+                }
+                virCommandAddArg(cmd, devstr);
+
+                VIR_FREE(vhostfdName);
+                VIR_FREE(devstr);
+            }
+        }
     }
 
     return 0;
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index a793fb6..c6efe11 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -163,6 +163,11 @@ char *qemuBuildSCSIHostdevDrvStr(virDomainHostdevDefPtr dev);
 char *qemuBuildSCSIHostdevDevStr(const virDomainDef *def,
                                  virDomainHostdevDefPtr dev,
                                  virQEMUCapsPtr qemuCaps);
+char *
+qemuBuildHostHostdevDevStr(const virDomainDef *def,
+                           virDomainHostdevDefPtr dev,
+                           virQEMUCapsPtr qemuCaps,
+                           char *vhostfdName);
 
 char *qemuBuildRedirdevDevStr(const virDomainDef *def,
                               virDomainRedirdevDefPtr dev,
diff --git a/src/qemu/qemu_domain_address.c b/src/qemu/qemu_domain_address.c
index e206b9f..90adcbc 100644
--- a/src/qemu/qemu_domain_address.c
+++ b/src/qemu/qemu_domain_address.c
@@ -310,6 +310,16 @@ qemuDomainPrimeVirtioDeviceAddresses(virDomainDefPtr def,
         }
     }
 
+    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_HOST &&
+            def->hostdevs[i]->source.subsys.u.host.protocol ==
+            VIR_DOMAIN_HOSTDEV_SUBSYS_HOST_PROTOCOL_TYPE_VHOST &&
+            def->hostdevs[i]->info->type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
+            def->hostdevs[i]->info->type = type;
+    }
+
     if (def->memballoon &&
         def->memballoon->model == VIR_DOMAIN_MEMBALLOON_MODEL_VIRTIO &&
         def->memballoon->info.type == VIR_DOMAIN_DEVICE_ADDRESS_TYPE_NONE)
diff --git a/src/qemu/qemu_hostdev.c b/src/qemu/qemu_hostdev.c
index dd3a3cf..29aedeb 100644
--- a/src/qemu/qemu_hostdev.c
+++ b/src/qemu/qemu_hostdev.c
@@ -292,6 +292,17 @@ qemuHostdevPrepareSCSIDevices(virQEMUDriverPtr driver,
                                         name, hostdevs, nhostdevs);
 }
 
+int
+qemuHostdevPrepareHostDevices(virQEMUDriverPtr driver,
+                              const char *name,
+                              virDomainHostdevDefPtr *hostdevs,
+                              int nhostdevs)
+{
+    virHostdevManagerPtr hostdev_mgr = driver->hostdevMgr;
+
+    return virHostdevPrepareHostDevices(hostdev_mgr, QEMU_DRIVER_NAME,
+                                        name, hostdevs, nhostdevs);
+}
 
 int
 qemuHostdevPrepareDomainDevices(virQEMUDriverPtr driver,
@@ -315,6 +326,10 @@ qemuHostdevPrepareDomainDevices(virQEMUDriverPtr driver,
                                       def->hostdevs, def->nhostdevs) < 0)
         return -1;
 
+    if (qemuHostdevPrepareHostDevices(driver, def->name,
+                                      def->hostdevs, def->nhostdevs) < 0)
+        return -1;
+
     return 0;
 }
 
@@ -370,6 +385,29 @@ qemuHostdevReAttachSCSIDevices(virQEMUDriverPtr driver,
 }
 
 void
+qemuHostdevReAttachHostDevices(virQEMUDriverPtr driver,
+                               const char *name,
+                               virDomainHostdevDefPtr *hostdevs,
+                               int nhostdevs)
+{
+    size_t i;
+    virHostdevManagerPtr hostdev_mgr = driver->hostdevMgr;
+
+    for (i = 0; i < nhostdevs; i++) {
+        virDomainHostdevDefPtr hostdev = hostdevs[i];
+        virDomainDeviceDef dev;
+
+        dev.type = VIR_DOMAIN_DEVICE_HOSTDEV;
+        dev.data.hostdev = hostdev;
+
+        ignore_value(qemuRemoveSharedDevice(driver, &dev, name));
+    }
+
+    virHostdevReAttachHostDevices(hostdev_mgr, QEMU_DRIVER_NAME,
+                                  name, hostdevs, nhostdevs);
+}
+
+void
 qemuHostdevReAttachDomainDevices(virQEMUDriverPtr driver,
                                  virDomainDefPtr def)
 {
@@ -384,4 +422,7 @@ qemuHostdevReAttachDomainDevices(virQEMUDriverPtr driver,
 
     qemuHostdevReAttachSCSIDevices(driver, def->name, def->hostdevs,
                                    def->nhostdevs);
+
+    qemuHostdevReAttachHostDevices(driver, def->name, def->hostdevs,
+                                   def->nhostdevs);
 }
diff --git a/src/qemu/qemu_hostdev.h b/src/qemu/qemu_hostdev.h
index 0a3c715..1788d12 100644
--- a/src/qemu/qemu_hostdev.h
+++ b/src/qemu/qemu_hostdev.h
@@ -55,6 +55,10 @@ int qemuHostdevPrepareSCSIDevices(virQEMUDriverPtr driver,
                                   const char *name,
                                   virDomainHostdevDefPtr *hostdevs,
                                   int nhostdevs);
+int qemuHostdevPrepareHostDevices(virQEMUDriverPtr driver,
+                                  const char *name,
+                                  virDomainHostdevDefPtr *hostdevs,
+                                  int nhostdevs);
 int qemuHostdevPrepareDomainDevices(virQEMUDriverPtr driver,
                                     virDomainDefPtr def,
                                     virQEMUCapsPtr qemuCaps,
@@ -72,6 +76,10 @@ void qemuHostdevReAttachSCSIDevices(virQEMUDriverPtr driver,
                                     const char *name,
                                     virDomainHostdevDefPtr *hostdevs,
                                     int nhostdevs);
+void qemuHostdevReAttachHostDevices(virQEMUDriverPtr driver,
+                                    const char *name,
+                                    virDomainHostdevDefPtr *hostdevs,
+                                    int nhostdevs);
 void qemuHostdevReAttachDomainDevices(virQEMUDriverPtr driver,
                                       virDomainDefPtr def);
 
-- 
1.9.1




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