* Gonglei (arei.gong...@huawei.com) wrote:
> Hi, Gerd
>
> I encounter a problem that breaking migration from qemu-1.5 to qemu-2.1.
> The error message as below:
> qemu-system-x86_64: hw/input/hid.c:121: hid_pointer_event: Assertion `hs->n
> < 16' failed.
> Qemu assert in hid_pointer_event().
What is your test to reproduce this?
Dave
> I get the value of hs->n which is 16 by reproduction. And the code of
> qemu-1.5 :
>
> static void hid_pointer_event(void *opaque,
> int x1, int y1, int z1, int buttons_state)
> {
> HIDState *hs = opaque;
> unsigned use_slot = (hs->head + hs->n - 1) & QUEUE_MASK;
> unsigned previous_slot = (use_slot - 1) & QUEUE_MASK;
>
> if (hs->n == QUEUE_LENGTH) {
> /* Queue full. Discard old button state, combine motion normally. */
> hs->ptr.queue[use_slot].buttons_state = buttons_state;
> }
>
> Which indicate it is legal when hs->n == QUEUE_LENGTH.
>
> But now:
> static void hid_pointer_event(DeviceState *dev, QemuConsole *src,
> InputEvent *evt)
> {
> static const int bmap[INPUT_BUTTON_MAX] = {
> [INPUT_BUTTON_LEFT] = 0x01,
> [INPUT_BUTTON_RIGHT] = 0x02,
> [INPUT_BUTTON_MIDDLE] = 0x04,
> };
> HIDState *hs = (HIDState *)dev;
> HIDPointerEvent *e;
>
> assert(hs->n < QUEUE_LENGTH);
> e = &hs->ptr.queue[(hs->head + hs->n) & QUEUE_MASK];
> ...
>
> static void hid_pointer_sync(DeviceState *dev)
> {
> HIDState *hs = (HIDState *)dev;
> HIDPointerEvent *prev, *curr, *next;
> bool event_compression = false;
>
> if (hs->n == QUEUE_LENGTH-1) {
> /*
> * Queue full. We are losing information, but we at least
> * keep track of most recent button state.
> */
> return;
> }
>
> What about this patch:
>
> diff --git a/hw/input/hid.c b/hw/input/hid.c
> index 148c003..56e0637 100644
> --- a/hw/input/hid.c
> +++ b/hw/input/hid.c
> @@ -116,7 +116,7 @@ static void hid_pointer_event(DeviceState *dev,
> QemuConsole *src,
> HIDState *hs = (HIDState *)dev;
> HIDPointerEvent *e;
>
> - assert(hs->n < QUEUE_LENGTH);
> + assert(hs->n <= QUEUE_LENGTH);
> e = &hs->ptr.queue[(hs->head + hs->n) & QUEUE_MASK];
>
> switch (evt->kind) {
>
> Best regards,
> -Gonglei
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
