virhostdev: Introduce and use virHostdevIsVFIODevice

In some places we need to check if a hostdev has VFIO backend.
Because of how complicated virDomainHostdevDef structure is, the
check consists of three lines. Move them to a function and
replace all checks with the function call.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NCole Robinson <crobinso@redhat.com>

src/conf/domain_conf.c

@@ -31486,10 +31486,7 @@ virDomainDefHasVFIOHostdev(const virDomainDef *def)
     size_t i;
 
     for (i = 0; i < def->nhostdevs; i++) {
-        const virDomainHostdevDef *tmp = def->hostdevs[i];
-        if (tmp->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-            tmp->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
-            tmp->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO)
+        if (virHostdevIsVFIODevice(def->hostdevs[i]))
             return true;
     }
 

src/libvirt_private.syms

@@ -2112,6 +2112,7 @@ virHostCPUStatsAssign;
 virHostdevFindUSBDevice;
 virHostdevIsMdevDevice;
 virHostdevIsSCSIDevice;
+virHostdevIsVFIODevice;
 virHostdevManagerGetDefault;
 virHostdevPCINodeDeviceDetach;
 virHostdevPCINodeDeviceReAttach;

src/qemu/qemu_cgroup.c

@@ -413,9 +413,7 @@ qemuTeardownHostdevCgroup(virDomainObjPtr vm,
     if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_DEVICES))
         return 0;
 
-    if (dev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-        dev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
-        dev->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO &&
+    if (virHostdevIsVFIODevice(dev) &&
         qemuDomainGetHostdevPath(vm->def, dev, true,
                                  &npaths, &path, NULL) < 0)
         goto cleanup;

src/qemu/qemu_domain.c

@@ -11761,9 +11761,7 @@ getPPC64MemLockLimitBytes(virDomainDefPtr def)
     for (i = 0; i < def->nhostdevs; i++) {
         virDomainHostdevDefPtr dev = def->hostdevs[i];
 
-        if (dev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-            dev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
-            dev->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO) {
+        if (virHostdevIsVFIODevice(dev)) {
             usesVFIO = true;
 
             pciAddr = &dev->source.subsys.u.pci.addr;
@@ -11915,12 +11913,8 @@ qemuDomainGetMemLockLimitBytes(virDomainDefPtr def)
      * Note that this may not be valid for all platforms.
      */
     for (i = 0; i < def->nhostdevs; i++) {
-        virDomainHostdevSubsysPtr subsys = &def->hostdevs[i]->source.subsys;
-
-        if (def->hostdevs[i]->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-            (subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV ||
-             (subsys->type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
-              subsys->u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO))) {
+        if (virHostdevIsVFIODevice(def->hostdevs[i]) ||
+            virHostdevIsMdevDevice(def->hostdevs[i])) {
             memKB = virDomainDefGetMemoryTotal(def) + 1024 * 1024;
             goto done;
         }

src/qemu/qemu_hotplug.c

@@ -4437,16 +4437,10 @@ qemuDomainRemoveHostDevice(virQEMUDriverPtr driver,
     qemuDomainObjPrivatePtr priv = vm->privateData;
     g_autofree char *drivealias = NULL;
     g_autofree char *objAlias = NULL;
-    bool is_vfio = false;
 
     VIR_DEBUG("Removing host device %s from domain %p %s",
               hostdev->info->alias, vm, vm->def->name);
 
-    if (hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI) {
-        int backend = hostdev->source.subsys.u.pci.backend;
-        is_vfio = backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO;
-    }
-
     if (hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI) {
         virDomainHostdevSubsysSCSIPtr scsisrc = &hostdev->source.subsys.u.scsi;
         virDomainHostdevSubsysSCSIiSCSIPtr iscsisrc = &scsisrc->u.iscsi;
@@ -4494,7 +4488,7 @@ qemuDomainRemoveHostDevice(virQEMUDriverPtr driver,
 
     virDomainAuditHostdev(vm, hostdev, "detach", true);
 
-    if (!is_vfio &&
+    if (!virHostdevIsVFIODevice(hostdev) &&
         qemuSecurityRestoreHostdevLabel(driver, vm, hostdev) < 0)
         VIR_WARN("Failed to restore host device labelling");
 

src/util/virhostdev.c

@@ -389,6 +389,21 @@ virHostdevIsMdevDevice(const virDomainHostdevDef *hostdev)
 }
 
 
+/**
+ * virHostdevIsVFIODevice:
+ * @hostdev: host device to check
+ *
+ * Returns true if @hostdev is a PCI device with VFIO backend, false otherwise.
+ */
+bool
+virHostdevIsVFIODevice(const virDomainHostdevDef *hostdev)
+{
+    return hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
+        hostdev->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
+        hostdev->source.subsys.u.pci.backend == VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO;
+}
+
+
 static int
 virHostdevNetConfigVirtPortProfile(const char *linkdev, int vf,
                                    virNetDevVPortProfilePtr virtPort,

src/util/virhostdev.h

@@ -193,6 +193,9 @@ virHostdevIsSCSIDevice(const virDomainHostdevDef *hostdev)
 bool
 virHostdevIsMdevDevice(const virDomainHostdevDef *hostdev)
     ATTRIBUTE_NONNULL(1);
+bool
+virHostdevIsVFIODevice(const virDomainHostdevDef *hostdev)
+    ATTRIBUTE_NONNULL(1);
 
 /* functions used by NodeDevDetach/Reattach/Reset */
 int virHostdevPCINodeDeviceDetach(virHostdevManagerPtr mgr,