[libvirt] [PATCH v2] Do not generate security_model when fs driver is anything but 'path'

[Deepak C Shetty]

QEMU does not support security_model for anything but 'path' fs driver type.
Currently in libvirt, when security_model ( accessmode attribute) is not
specified it auto-generates it irrespective of the fs driver type, which
can result in a qemu error for drivers other than path. This patch ensures
that the qemu cmdline is correctly generated by taking into account the
fs driver type.

Signed-off-by: Deepak C Shetty <deepakcs at linux.vnet.ibm.com>
---
v2:
- removed xml accessmode changes as suggested by dan.
- every fs driver having a default accessmode always, retained.

 src/qemu/qemu_command.c |   23 +++++++++++++++++------
 1 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index ea1b763..e3a509a 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -2098,13 +2098,24 @@ char *qemuBuildFSStr(virDomainFSDefPtr fs,
     }
     virBufferAdd(&opt, driver, -1);
 
-    if (fs->accessmode == VIR_DOMAIN_FS_ACCESSMODE_MAPPED) {
-        virBufferAddLit(&opt, ",security_model=mapped");
-    } else if(fs->accessmode == VIR_DOMAIN_FS_ACCESSMODE_PASSTHROUGH) {
-        virBufferAddLit(&opt, ",security_model=passthrough");
-    } else if(fs->accessmode == VIR_DOMAIN_FS_ACCESSMODE_SQUASH) {
-        virBufferAddLit(&opt, ",security_model=none");
+    if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_PATH ||
+        fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_DEFAULT) {
+        if (fs->accessmode == VIR_DOMAIN_FS_ACCESSMODE_MAPPED) {
+            virBufferAddLit(&opt, ",security_model=mapped");
+        } else if(fs->accessmode == VIR_DOMAIN_FS_ACCESSMODE_PASSTHROUGH) {
+            virBufferAddLit(&opt, ",security_model=passthrough");
+        } else if(fs->accessmode == VIR_DOMAIN_FS_ACCESSMODE_SQUASH) {
+            virBufferAddLit(&opt, ",security_model=none");
+        }
+    } else {
+        /* For other fs drivers, default(passthru) should always */
+        /* be supported */
+        if (fs->accessmode != VIR_DOMAIN_FS_ACCESSMODE_PASSTHROUGH) {
+            qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                        _("only supports passthrough accessmode"));
+        }
     }
+
     virBufferAsprintf(&opt, ",id=%s%s", QEMU_FSDEV_HOST_PREFIX, fs->info.alias);
     virBufferAsprintf(&opt, ",path=%s", fs->src);