[libvirt] [RFC PATCH v2 12/18] hostdev: Introduce a reattach method for mediated devices

[Erik Skultety]

The name "reattach" does not really reflect the truth behind mediated
devices, since these are purely software devices that do not need to be
plugged back into the host in any way, however this patch pushes for
naming consistency for methods where the logic behind the underlying
operation stays the same except that in case of mdevs the operation
itself is effectively a NO-OP.

Signed-off-by: Erik Skultety <eskultet at redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/qemu/qemu_hostdev.c  | 15 ++++++++++++++
 src/qemu/qemu_hostdev.h  |  4 ++++
 src/util/virhostdev.c    | 53 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/util/virhostdev.h    |  7 +++++++
 5 files changed, 80 insertions(+)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 97f81ee..52aa7eb 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1715,6 +1715,7 @@ virHostdevPrepareSCSIDevices;
 virHostdevPrepareSCSIVHostDevices;
 virHostdevPrepareUSBDevices;
 virHostdevReAttachDomainDevices;
+virHostdevReAttachMediatedDevices;
 virHostdevReAttachPCIDevices;
 virHostdevReAttachSCSIDevices;
 virHostdevReAttachSCSIVHostDevices;
diff --git a/src/qemu/qemu_hostdev.c b/src/qemu/qemu_hostdev.c
index 45b731c..6a7232f 100644
--- a/src/qemu/qemu_hostdev.c
+++ b/src/qemu/qemu_hostdev.c
@@ -419,6 +419,18 @@ qemuHostdevReAttachSCSIVHostDevices(virQEMUDriverPtr driver,
 }
 
 void
+qemuHostdevReAttachMediatedDevices(virQEMUDriverPtr driver,
+                                   const char *name,
+                                   virDomainHostdevDefPtr *hostdevs,
+                                   int nhostdevs)
+{
+    virHostdevManagerPtr hostdev_mgr = driver->hostdevMgr;
+
+    virHostdevReAttachMediatedDevices(hostdev_mgr, QEMU_DRIVER_NAME,
+                                      name, hostdevs, nhostdevs);
+}
+
+void
 qemuHostdevReAttachDomainDevices(virQEMUDriverPtr driver,
                                  virDomainDefPtr def)
 {
@@ -436,4 +448,7 @@ qemuHostdevReAttachDomainDevices(virQEMUDriverPtr driver,
 
     qemuHostdevReAttachSCSIVHostDevices(driver, def->name, def->hostdevs,
                                         def->nhostdevs);
+
+    qemuHostdevReAttachMediatedDevices(driver, def->name, def->hostdevs,
+                                       def->nhostdevs);
 }
diff --git a/src/qemu/qemu_hostdev.h b/src/qemu/qemu_hostdev.h
index 9399241..0096497 100644
--- a/src/qemu/qemu_hostdev.h
+++ b/src/qemu/qemu_hostdev.h
@@ -84,6 +84,10 @@ void qemuHostdevReAttachSCSIVHostDevices(virQEMUDriverPtr driver,
                                          const char *name,
                                          virDomainHostdevDefPtr *hostdevs,
                                          int nhostdevs);
+void qemuHostdevReAttachMediatedDevices(virQEMUDriverPtr driver,
+                                        const char *name,
+                                        virDomainHostdevDefPtr *hostdevs,
+                                        int nhostdevs);
 void qemuHostdevReAttachDomainDevices(virQEMUDriverPtr driver,
                                       virDomainDefPtr def);
 
diff --git a/src/util/virhostdev.c b/src/util/virhostdev.c
index 681f720..2a43b4d 100644
--- a/src/util/virhostdev.c
+++ b/src/util/virhostdev.c
@@ -1963,6 +1963,59 @@ virHostdevReAttachSCSIVHostDevices(virHostdevManagerPtr mgr,
     virObjectUnlock(mgr->activeSCSIVHostHostdevs);
 }
 
+void
+virHostdevReAttachMediatedDevices(virHostdevManagerPtr mgr,
+                                  const char *drv_name,
+                                  const char *dom_name,
+                                  virDomainHostdevDefPtr *hostdevs,
+                                  int nhostdevs)
+{
+    const char *used_by_drvname = NULL;
+    const char *used_by_domname = NULL;
+    virDomainHostdevDefPtr hostdev = NULL;
+    virDomainHostdevSubsysMediatedDevPtr mdevsrc = NULL;
+    size_t i;
+
+    if (nhostdevs == 0)
+        return;
+
+    virObjectLock(mgr->activeMediatedHostdevs);
+    for (i = 0; i < nhostdevs; i++) {
+        virMediatedDevicePtr mdev, tmp;
+
+        hostdev = hostdevs[i];
+        mdevsrc = &hostdev->source.subsys.u.mdev;
+
+        if (hostdev->mode != VIR_DOMAIN_HOSTDEV_MODE_SUBSYS ||
+            hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_MDEV)
+            continue;
+
+        if (!(mdev = virMediatedDeviceNew(mdevsrc->uuidstr))) {
+            VIR_WARN("Failed to reattach mediated device %s attached to "
+                     "domain %s", mdevsrc->uuidstr, dom_name);
+            continue;
+        }
+
+        /* Remove from the list only mdevs assigned to @drv_name/@dom_name */
+
+        tmp = virMediatedDeviceListFind(mgr->activeMediatedHostdevs, mdev);
+        virMediatedDeviceFree(mdev);
+
+        /* skip inactive devices */
+        if (!tmp)
+            continue;
+
+        virMediatedDeviceGetUsedBy(tmp, &used_by_drvname, &used_by_domname);
+        if (STREQ_NULLABLE(drv_name, used_by_drvname) &&
+            STREQ_NULLABLE(dom_name, used_by_domname)) {
+            VIR_DEBUG("Removing %s dom=%s from activeMediatedHostdevs",
+                      mdevsrc->uuidstr, dom_name);
+            virMediatedDeviceListDel(mgr->activeMediatedHostdevs, tmp);
+        }
+    }
+    virObjectUnlock(mgr->activeMediatedHostdevs);
+}
+
 int
 virHostdevPCINodeDeviceDetach(virHostdevManagerPtr mgr,
                               virPCIDevicePtr pci)
diff --git a/src/util/virhostdev.h b/src/util/virhostdev.h
index b077089..d0875d8 100644
--- a/src/util/virhostdev.h
+++ b/src/util/virhostdev.h
@@ -134,6 +134,13 @@ virHostdevReAttachSCSIVHostDevices(virHostdevManagerPtr hostdev_mgr,
                                    virDomainHostdevDefPtr *hostdevs,
                                    int nhostdevs)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
+void
+virHostdevReAttachMediatedDevices(virHostdevManagerPtr hostdev_mgr,
+                                  const char *drv_name,
+                                  const char *dom_name,
+                                  virDomainHostdevDefPtr *hostdevs,
+                                  int nhostdevs)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);
 int
 virHostdevUpdateActivePCIDevices(virHostdevManagerPtr mgr,
                                  virDomainHostdevDefPtr *hostdevs,
-- 
2.10.2