pc: kvm: check if KVM has free memory slots to avoid abort()

When more memory devices are used than available
KVM memory slots, QEMU crashes with:

kvm_alloc_slot: no free slot available
Aborted (core dumped)

Fix this by checking that KVM has a free slot before
attempting to map memory in guest address space.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 1205db83bc..ce7b75217a 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1598,6 +1598,11 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
+    if (kvm_enabled() && !kvm_has_free_slot(machine)) {
+        error_setg(&local_err, "hypervisor has no free memory slots left");
+        goto out;
+    }
+
     memory_region_add_subregion(&pcms->hotplug_memory,
                                 addr - pcms->hotplug_memory_base, mr);
     vmstate_register_ram(mr, dev);