[PATCH 3/4] qemu_validate: Validate prealloc threads against qemuCpas

[Michal Privoznik <mprivozn@xxxxxxxxxx>]

Only fairly new QEMUs are capable of user provided number of
preallocation threads. Validate this assumption.

Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
---
 src/qemu/qemu_validate.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
index f27e480696..e0708b8a76 100644
--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@@ -739,6 +739,13 @@ qemuValidateDomainDefMemory(const virDomainDef *def,
         return -1;
     }
 
+    if (mem->allocation_threads > 0 &&
+        !virQEMUCapsGet(qemuCaps, QEMU_CAPS_MEMORY_BACKEND_PREALLOC_THREADS)) {
+        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
+                       _("preallocation threads are unsupported with this QEMU"));
+        return -1;
+    }
+
     if (mem->source == VIR_DOMAIN_MEMORY_SOURCE_ANONYMOUS) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                        _("hugepages are not allowed with anonymous "
-- 
2.34.1