On 03/07/18 22:26, Christoffer Dall wrote:
> The vgic_init function can race with kvm_arch_vcpu_create() which does
> not hold kvm_lock() and we therefore have no synchronization primitives
> to ensure we're doing the right thing.
>
> As the user is trying to initialize or run the VM while at the same time
> creating more VCPUs, we just have to refuse to initialize the VGIC in
> this case rather than silently failing with a broken VCPU.
>
> Signed-off-by: Christoffer Dall <[email protected]>
> ---
> virt/kvm/arm/vgic/vgic-init.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index 9406eaf..c0c0b88 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -286,6 +286,10 @@ int vgic_init(struct kvm *kvm)
> if (vgic_initialized(kvm))
> return 0;
>
> + /* Are we also in the middle of creating a VCPU? */
> + if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
> + return -EBUSY;
> +
> /* freeze the number of spis */
> if (!dist->nr_spis)
> dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
>
Applied to queue.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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