From: David Matlack <dmatlack@xxxxxxxxxx> commit 258785ef08b323bddd844b4926a32c2b2045a1b0 upstream. When growing halt-polling, there is no check that the poll time exceeds the per-VM limit. It's possible for vcpu->halt_poll_ns to grow past kvm->max_halt_poll_ns and stay there until a halt which takes longer than kvm->halt_poll_ns. Signed-off-by: David Matlack <dmatlack@xxxxxxxxxx> Signed-off-by: Venkatesh Srinivas <venkateshs@xxxxxxxxxxxx> Message-Id: <20210506152442.4010298-1-venkateshs@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- virt/kvm/kvm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2717,8 +2717,8 @@ static void grow_halt_poll_ns(struct kvm if (val < grow_start) val = grow_start; - if (val > halt_poll_ns) - val = halt_poll_ns; + if (val > vcpu->kvm->max_halt_poll_ns) + val = vcpu->kvm->max_halt_poll_ns; vcpu->halt_poll_ns = val; out:
