qemu: Pre-create pstore device file

So far we are relying on QEMU or sysadmin to create the file for
pstore. This is suboptimal as in the case of the former we can
not set proper seclabels (there's nothing to set seclabels on
until QEMU is started).

Therefore, make sure the file is created before launching QEMU
and that it has the correct size.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>

diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 6255ba92e77583dc8893ade3c22e7a2c325ea57f..cec739c98424637873d9a3093ff25dd098e8dab2 100644 (file)
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6835,6 +6835,48 @@ qemuProcessPrepareLaunchSecurityGuestInput(virDomainObj *vm)
 }
 
 
+static int
+qemuProcessPreparePstore(virDomainObj *vm)
+{
+    virDomainPstoreDef *pstore = vm->def->pstore;
+    VIR_AUTOCLOSE fd = -1;
+
+    if (!pstore)
+        return 0;
+
+    switch (pstore->backend) {
+    case VIR_DOMAIN_PSTORE_BACKEND_ACPI_ERST:
+        if ((fd = open(pstore->path, O_WRONLY | O_CREAT, 0600)) < 0) {
+            virReportSystemError(errno,
+                                 _("cannot create file '%1$s'"),
+                                 pstore->path);
+            return -1;
+        }
+
+        if (ftruncate(fd, pstore->size * 1024) < 0) {
+            virReportSystemError(errno,
+                                 _("Failed to truncate file '%1$s'"),
+                                 pstore->path);
+            return -1;
+        }
+
+        if (VIR_CLOSE(fd) < 0) {
+            virReportSystemError(errno,
+                                 _("Unable to save '%1$s'"),
+                                 pstore->path);
+            return -1;
+        }
+
+        break;
+
+    case VIR_DOMAIN_PSTORE_BACKEND_LAST:
+        break;
+    }
+
+    return 0;
+}
+
+
 static int
 qemuProcessPrepareHostStorageSourceVDPA(virStorageSource *src,
                                         qemuDomainObjPrivate *priv)
@@ -7333,6 +7375,9 @@ qemuProcessPrepareHost(virQEMUDriver *driver,
     if (qemuProcessPrepareLaunchSecurityGuestInput(vm) < 0)
         return -1;
 
+    if (qemuProcessPreparePstore(vm) < 0)
+        return -1;
+
     return 0;
 }