diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index dc949db4dd..9673e8e7e5 100644
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -428,8 +428,7 @@ qemuSetupMemoryCgroup(virDomainObjPtr vm)
         }
     }
 
-    if (virCgroupSetMemoryHardLimit(priv->cgroup,
-                                    qemuDomainMemoryLimit(vm->def)) < 0)
+    if (virCgroupSetMemoryHardLimit(priv->cgroup, vm->def->mem.hard_limit) < 0)
         return -1;
 
     if (vm->def->mem.soft_limit != 0 &&
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 8b628d68d5..c8f7df227c 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -9220,7 +9220,7 @@ qemuBuildCommandLine(virConnectPtr conn,
     }
 
     if (mlock)
-        virCommandSetMaxMemLock(cmd, qemuDomainMemoryLimit(def) * 1024);
+        virCommandSetMaxMemLock(cmd, def->mem.hard_limit * 1024);
 
     virObjectUnref(cfg);
     return cmd;
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 393af6b68f..7f4d17d126 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -2306,55 +2306,6 @@ cleanup:
     return ret;
 }
 
-
-unsigned long long
-qemuDomainMemoryLimit(virDomainDefPtr def)
-{
-    unsigned long long mem;
-    size_t i;
-
-    if (def->mem.hard_limit) {
-        mem = def->mem.hard_limit;
-    } else {
-        /* If there is no hard_limit set, compute a reasonable one to avoid
-         * system thrashing caused by exploited qemu.  A 'reasonable
-         * limit' has been chosen:
-         *     (1 + k) * (domain memory + total video memory) + (32MB for
-         *     cache per each disk) + F
-         * where k = 0.5 and F = 400MB.  The cache for disks is important as
-         * kernel cache on the host side counts into the RSS limit.
-         * Moreover, VFIO requires some amount for IO space. Alex Williamson
-         * suggested adding 1GiB for IO space just to be safe (some finer
-         * tuning might be nice, though).
-         *
-         * Technically, the disk cache does not have to be included in
-         * RLIMIT_MEMLOCK but it doesn't hurt as it's just an upper limit and
-         * it makes this function and its usage simpler.
-         */
-        mem = def->mem.max_balloon;
-        for (i = 0; i < def->nvideos; i++)
-            mem += def->videos[i]->vram;
-        mem *= 1.5;
-        mem += def->ndisks * 32768;
-        mem += 409600;
-
-        for (i = 0; i < def->nhostdevs; i++) {
-            virDomainHostdevDefPtr hostdev = def->hostdevs[i];
-            if (hostdev->mode == VIR_DOMAIN_HOSTDEV_MODE_SUBSYS &&
-                hostdev->source.subsys.type ==
-                    VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_PCI &&
-                hostdev->source.subsys.u.pci.backend ==
-                    VIR_DOMAIN_HOSTDEV_PCI_BACKEND_VFIO) {
-                mem += 1024 * 1024;
-                break;
-            }
-        }
-    }
-
-    return mem;
-}
-
-
 int
 qemuDomainUpdateDeviceList(virQEMUDriverPtr driver,
                            virDomainObjPtr vm)
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 0a4a51ec4e..21f116c6d3 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -365,8 +365,6 @@ extern virDomainXMLPrivateDataCallbacks virQEMUDriverPrivateDataCallbacks;
 extern virDomainXMLNamespace virQEMUDriverDomainXMLNamespace;
 extern virDomainDefParserConfig virQEMUDriverDomainDefParserConfig;
 
-unsigned long long qemuDomainMemoryLimit(virDomainDefPtr def);
-
 int qemuDomainUpdateDeviceList(virQEMUDriverPtr driver,
                                virDomainObjPtr vm);
 
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 85d2ca9fab..478f33183b 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1030,7 +1030,7 @@ int qemuDomainAttachHostPciDevice(virQEMUDriverPtr driver,
          */
         vm->def->hostdevs[vm->def->nhostdevs++] = hostdev;
         virProcessSetMaxMemLock(vm->pid,
-                                qemuDomainMemoryLimit(vm->def) * 1024);
+                                vm->def->mem.hard_limit * 1024);
         vm->def->hostdevs[vm->def->nhostdevs--] = NULL;
     }