[PATCH 2/2] xl/vcpuset: Make it work for PV guests.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

When we try to set the number of VCPUs for a PV guest we might
have QEMU running serving the framebuffer, or not. Either way
we should not use QMP when trying to alter the number of VCPUs
a PV guest can have.

This fixes the bug where for a PV guest 'xl vcpuset' results in:
libxl: error: libxl_qmp.c:702:libxl__qmp_initialize: Connection error: No such file or directory

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 tools/libxl/libxl.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 0879f23..8786074 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -4307,16 +4307,28 @@ int libxl_set_vcpuonline(libxl_ctx *ctx, uint32_t domid, libxl_bitmap *cpumap)
 {
     GC_INIT(ctx);
     int rc;
-    switch (libxl__device_model_version_running(gc, domid)) {
-    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL:
+
+    libxl_domain_type type = libxl__domain_type(gc, domid);
+    if (type == LIBXL_DOMAIN_TYPE_INVALID) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    if (type == LIBXL_DOMAIN_TYPE_PV)
         rc = libxl__set_vcpuonline_xenstore(gc, domid, cpumap);
-        break;
-    case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
-        rc = libxl__set_vcpuonline_qmp(gc, domid, cpumap);
-        break;
-    default:
-        rc = ERROR_INVAL;
+    else {
+        switch (libxl__device_model_version_running(gc, domid)) {
+        case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL:
+            rc = libxl__set_vcpuonline_xenstore(gc, domid, cpumap);
+            break;
+        case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
+            rc = libxl__set_vcpuonline_qmp(gc, domid, cpumap);
+            break;
+        default:
+            rc = ERROR_INVAL;
+        }
     }
+out:
     GC_FREE;
     return rc;
 }
-- 
1.8.3.1