On Thu, Apr 24, 2014 at 08:06:19PM +0800, [email protected] wrote: > From: Gonglei <[email protected]> > > According to the PS/2 Mouse/Keyboard Protocol, the keyboard outupt buffer size > is 16 bytes. And the PS2_QUEUE_SIZE 256 was introduced in Qemu from the very > beginning. > > When I started a redhat5.6 32bit guest, meanwhile tapped the keyboard as > quickly as > possible, the screen would show me "i8042.c: No controller found". As a > result, > I couldn't use the keyboard in the VNC client. > > Previous discussion about the issue in maillist: > http://thread.gmane.org/gmane.comp.emulators.qemu/43294/focus=47180 > > This patch has been tested on redhat5.6 32-bit/suse11sp3 64-bit guests. > More easy meathod to reproduce: > 1.boot a guest with libvirt. > 2.connect to VNC client. > 3.as you see the BIOS, bootloader, Linux booting, run the follow simply shell > script: > for((i=0;i<10000000;i++)) do virsh send-key redhat5.6 KEY_A; done
Why we can't break keyboard by flooding input after boot up? > Actual results: > dmesg show "i8042.c: No controller found." And the keyboard is out of work. > > Signed-off-by: Gonglei <[email protected]> > --- > v2: rework by Gerd Hoffmann's suggestion: > - adjust the code style > - adjust the ps/2 mouse queue buffer judging condition > - add pre_save() for ps/2 keyboard and mouse > v3: > - change the check enough buffer for ps2_mouse_send_packet() call > as suggested by Gerd Hoffmann. > > hw/input/ps2.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++---- > 1 files changed, 68 insertions(+), 6 deletions(-) > > diff --git a/hw/input/ps2.c b/hw/input/ps2.c > index 3412079..b7835c2 100644 > --- a/hw/input/ps2.c > +++ b/hw/input/ps2.c > @@ -71,10 +71,12 @@ > #define MOUSE_STATUS_ENABLED 0x20 > #define MOUSE_STATUS_SCALE21 0x10 > > -#define PS2_QUEUE_SIZE 256 > +#define PS2_QUEUE_SIZE 16 /* Buffer size required by PS/2 protocol */ > > typedef struct { > - uint8_t data[PS2_QUEUE_SIZE]; > + /* Keep the data array 256 bytes long, which compatibility > + with older qemu versions. */ > + uint8_t data[256]; > int rptr, wptr, count; > } PS2Queue; > > @@ -137,7 +139,7 @@ void ps2_queue(void *opaque, int b) > PS2State *s = (PS2State *)opaque; > PS2Queue *q = &s->queue; > > - if (q->count >= PS2_QUEUE_SIZE) > + if (q->count >= PS2_QUEUE_SIZE - 1) > return; > q->data[q->wptr] = b; > if (++q->wptr == PS2_QUEUE_SIZE) > @@ -374,9 +376,8 @@ static void ps2_mouse_event(void *opaque, > qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); > } > > - if (!(s->mouse_status & MOUSE_STATUS_REMOTE) && > - (s->common.queue.count < (PS2_QUEUE_SIZE - 16))) { > - for(;;) { > + if (!(s->mouse_status & MOUSE_STATUS_REMOTE)) { > + while (s->common.queue.count < PS2_QUEUE_SIZE - 4) { > /* if not remote, send event. Multiple events are sent if > too big deltas */ > ps2_mouse_send_packet(s); > @@ -528,6 +529,34 @@ static void ps2_common_reset(PS2State *s) > s->update_irq(s->update_arg, 0); > } > > +static void ps2_common_post_load(PS2State *s) > +{ > + PS2Queue *q = &s->queue; > + int size; > + int i; > + int tmp_data[PS2_QUEUE_SIZE]; > + > + /* set the useful data buffer queue size, < PS2_QUEUE_SIZE */ > + size = q->count > PS2_QUEUE_SIZE ? 0 : q->count; > + > + /* move the queue elements to the start of data array */ > + if (size > 0) { > + for (i = 0; i < size; i++) { > + /* move the queue elements to the temporary buffer */ > + tmp_data[i] = q->data[q->rptr]; > + if (++q->rptr == 256) { > + q->rptr = 0; > + } > + } > + memcpy(q->data, tmp_data, size); > + } > + /* reset rptr/wptr/count */ > + q->rptr = 0; > + q->wptr = size; > + q->count = size; > + s->update_irq(s->update_arg, q->count != 0); > +} > + > static void ps2_kbd_reset(void *opaque) > { > PS2KbdState *s = (PS2KbdState *) opaque; > @@ -600,18 +629,31 @@ static const VMStateDescription > vmstate_ps2_keyboard_ledstate = { > static int ps2_kbd_post_load(void* opaque, int version_id) > { > PS2KbdState *s = (PS2KbdState*)opaque; > + PS2State *ps2 = &s->common; > > if (version_id == 2) > s->scancode_set=2; > + > + ps2_common_post_load(ps2); > + > return 0; > } > > +static void ps2_kbd_pre_save(void *opaque) > +{ > + PS2KbdState *s = (PS2KbdState *)opaque; > + PS2State *ps2 = &s->common; > + > + ps2_common_post_load(ps2); > +} > + > static const VMStateDescription vmstate_ps2_keyboard = { > .name = "ps2kbd", > .version_id = 3, > .minimum_version_id = 2, > .minimum_version_id_old = 2, > .post_load = ps2_kbd_post_load, > + .pre_save = ps2_kbd_pre_save, > .fields = (VMStateField []) { > VMSTATE_STRUCT(common, PS2KbdState, 0, vmstate_ps2_common, PS2State), > VMSTATE_INT32(scan_enabled, PS2KbdState), > @@ -629,11 +671,31 @@ static const VMStateDescription vmstate_ps2_keyboard = { > } > }; > > +static int ps2_mouse_post_load(void *opaque, int version_id) > +{ > + PS2MouseState *s = (PS2MouseState *)opaque; > + PS2State *ps2 = &s->common; > + > + ps2_common_post_load(ps2); > + > + return 0; > +} > + > +static void ps2_mouse_pre_save(void *opaque) > +{ > + PS2MouseState *s = (PS2MouseState *)opaque; > + PS2State *ps2 = &s->common; > + > + ps2_common_post_load(ps2); > +} > + > static const VMStateDescription vmstate_ps2_mouse = { > .name = "ps2mouse", > .version_id = 2, > .minimum_version_id = 2, > .minimum_version_id_old = 2, > + .post_load = ps2_mouse_post_load, > + .pre_save = ps2_mouse_pre_save, > .fields = (VMStateField []) { > VMSTATE_STRUCT(common, PS2MouseState, 0, vmstate_ps2_common, > PS2State), > VMSTATE_UINT8(mouse_status, PS2MouseState), > -- > 1.6.0.2 > > -- Amos.
