Re: [Qemu-devel] [PATCH] e1000/rtl8139: forbid dealing with packets when VM is paused

[Zhanghailiang]

Hi Amos:
Thanks for replying.

> I'm ok with the patch idea.
> 
> On Sat, Apr 26, 2014 at 06:19:12PM +0800, zhanghailiang wrote:
> > For e1000/rtl8139, qemu can still send/receive packets when VM is paused.
> 
> ^^^^^^^^^
>                                                            ->
> isn't running
> 
> There are many kinds of RunState, "is paused" doesn't equal to "isn't 
> running".
Yes, you are right, this is my fault:) 
> 
> > If this happened in *migration's* last PAUSE VM stage, the new dirty RAM
> related to the packets will be missed.
> > To avoid this, do things like virtio-net, forbid sending/receiving
> > packets when VM is suspend.
>                   ^^^^^^^^^^^  -> isn't running.
> 
> > Signed-off-by: zhanghailiang <address@hidden>
> 
> > ---
> >  hw/net/e1000.c   | 5 +++--
> >  hw/net/rtl8139.c | 3 +++
> >  2 files changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/net/e1000.c b/hw/net/e1000.c index 8387443..94108fd
> > 100644
> > --- a/hw/net/e1000.c
> > +++ b/hw/net/e1000.c
> > @@ -885,9 +885,10 @@ static int
> >  e1000_can_receive(NetClientState *nc)  {
> >      E1000State *s = qemu_get_nic_opaque(nc);
> > -
> > +    int vmstat = runstate_is_running();
> > +
> >      return (s->mac_reg[STATUS] & E1000_STATUS_LU) &&
> > -        (s->mac_reg[RCTL] & E1000_RCTL_EN) && e1000_has_rxbufs(s,
> 1);
> > +        (s->mac_reg[RCTL] & E1000_RCTL_EN) && e1000_has_rxbufs(s,
> 1)
> > + && vmstat;
> >  }
> >
> >  static uint64_t rx_desc_base(E1000State *s) diff --git
> > a/hw/net/rtl8139.c b/hw/net/rtl8139.c index 5329f44..3c60c84 100644
> > --- a/hw/net/rtl8139.c
> > +++ b/hw/net/rtl8139.c
> > @@ -799,7 +799,10 @@ static int rtl8139_can_receive(NetClientState
> > *nc)  {
> >      RTL8139State *s = qemu_get_nic_opaque(nc);
> >      int avail;
> > +    int vmstat = runstate_is_running();
> >
> > +    if (!vmstat)
> > +        return 0;
> 
>        if (!runstate_is_running())
>            return 0;
> 
> >      /* Receive (drop) packets if card is disabled.  */
> >      if (!s->clock_enabled)
> >        return 1;
> > --
> > 1.7.12.4
> >
> 
> --
>                       Amos.