[libvirt] [PATCH 4/6] unpriv_sgio: Manage unpriv_sgio in domain's lifecyle

[Osier Yang]

To record the original "unpriv_sgio" value, this introduces
"old_unpriv_sgio" for disk def. When the domain is starting,
the disk's "unpriv_sgio" is set with regards to the config
in domain XML. And when the domain is being destroyed, it's
restored to the original value ("old_unpriv_sgio")
---
 src/conf/domain_conf.h  |    1 +
 src/qemu/qemu_process.c |   31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 105fb7d..1a8de71 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -616,6 +616,7 @@ struct _virDomainDiskDef {
     bool rawio_specified;
     int rawio; /* no = 0, yes = 1 */
     int unpriv_sgio;  /* no = 0, yes = 1 */
+    int old_unpriv_sgio; /* To record the old unpriv_sgio value, internally */
 
     size_t nseclabels;
     virSecurityDeviceLabelDefPtr *seclabels;
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 3d7a5a0..e48eed0 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -3703,6 +3703,26 @@ int qemuProcessStart(virConnectPtr conn,
             virCommandAllowCap(cmd, CAP_SYS_RAWIO);
     }
 
+    /* Set unpriv_sgio for disks */
+    for (i = 0; i < vm->def->ndisks; i++) {
+        virDomainDiskDefPtr disk = vm->def->disks[i];
+        int old_unpriv_sgio;
+
+        if (!disk->unpriv_sgio)
+            continue;
+
+        if (virGetDeviceUnprivSGIO(disk->src, &old_unpriv_sgio) < 0)
+            goto cleanup;
+
+        disk->old_unpriv_sgio = old_unpriv_sgio;
+
+        if (virSetDeviceUnprivSGIO(disk->src,
+                                   (disk->unpriv_sgio ==
+                                    VIR_DOMAIN_DISK_UNPRIV_SGIO_YES)
+                                   ? 1 : 0) < 0)
+            goto cleanup;
+    }
+
     virCommandSetPreExecHook(cmd, qemuProcessHook, &hookData);
 
     virCommandSetOutputFD(cmd, &logfile);
@@ -4093,6 +4113,17 @@ void qemuProcessStop(struct qemud_driver *driver,
                                           flags & VIR_QEMU_PROCESS_STOP_MIGRATED);
     virSecurityManagerReleaseLabel(driver->securityManager, vm->def);
 
+    /* Restore disk's unpriv_sgio */
+    for (i = 0; i < vm->def->ndisks; i++) {
+        virDomainDiskDefPtr disk = vm->def->disks[i];
+
+        if (!disk->unpriv_sgio)
+            continue;
+
+        if (virSetDeviceUnprivSGIO(disk->src, disk->old_unpriv_sgio) < 0)
+            VIR_WARN("Unable to restore unpriv_sgio for disk '%s'", disk->src);
+    }
+
     /* Clear out dynamically assigned labels */
     for (i = 0; i < vm->def->nseclabels; i++) {
         if (vm->def->seclabels[i]->type == VIR_DOMAIN_SECLABEL_DYNAMIC) {
-- 
1.7.7.6