Commit b8865591 authored by Igor Mammedov's avatar Igor Mammedov Committed by Michael S. Tsirkin
Browse files

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: default avatarIgor Mammedov <imammedo@redhat.com>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent c4095726

hw/i386/pc.c

+5 −0
Original line number Diff line number Diff line
@@ -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);

include/sysemu/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ extern KVMState *kvm_state; 


/* external API */



bool kvm_has_free_slot(MachineState *ms);

int kvm_has_sync_mmu(void);

int kvm_has_vcpu_events(void);

int kvm_has_robust_singlestep(void);

kvm-all.c

+17 −1
Original line number Diff line number Diff line
@@ -132,7 +132,7 @@ static const KVMCapabilityInfo kvm_required_capabilites[] = { 
    KVM_CAP_LAST_INFO

};



static KVMSlot *kvm_alloc_slot(KVMState *s)

static KVMSlot *kvm_get_free_slot(KVMState *s)

{

    int i;
@@ -142,6 +142,22 @@ static KVMSlot *kvm_alloc_slot(KVMState *s) 
        }

    }



    return NULL;

}



bool kvm_has_free_slot(MachineState *ms)

{

    return kvm_get_free_slot(KVM_STATE(ms->accelerator));

}



static KVMSlot *kvm_alloc_slot(KVMState *s)

{

    KVMSlot *slot = kvm_get_free_slot(s);



    if (slot) {

        return slot;

    }



    fprintf(stderr, "%s: no free slot available\n", __func__);

    abort();

}

kvm-stub.c

+5 −0
Original line number Diff line number Diff line
@@ -147,4 +147,9 @@ int kvm_irqchip_remove_irqfd_notifier(KVMState *s, EventNotifier *n, int virq) 
{

    return -ENOSYS;

}



bool kvm_has_free_slot(MachineState *ms)

{

    return false;

}

#endif