From: David Matlack dmatlack@google.com
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@google.com Signed-off-by: Venkatesh Srinivas venkateshs@chromium.org Message-Id: 20210506152442.4010298-1-venkateshs@chromium.org Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -2734,8 +2734,8 @@ 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: