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

[Amos Kong]

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".

> 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.