From 38e3785cc76842f5a00c9f744f3a581a65b2a73a Mon Sep 17 00:00:00 2001
Message-Id: <38e3785cc76842f5a00c9f744f3a581a65b2a73a@dist-git>
From: Michal Privoznik <mprivozn@redhat.com>
Date: Mon, 21 Mar 2022 17:09:40 +0100
Subject: [PATCH] qemu_validate: Validate prealloc threads against qemuCpas

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

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
(cherry picked from commit 75a4e0165ef199809974e97b507d3953e1de01d1)
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2075628
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 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 3a69733f81..7bc14293d6 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 "
-- 
2.35.1