RE: [Xen-devel] Re: [PATCH][VT] fix bug that service os&vmx guest can'tcommunicate with each other.

["Li, Xin B" <xin.b.li@xxxxxxxxx>]

 >Why is special treatment needed for small packets? Is this simply 
>masking a bug elsewhere -- the original qemu driver must have dealt 
>with small packets (e.g., TCP acks) correctly.

Ethernet frame can not be less than 60 bytes.  When being sent out,
small frames will be extended to 60 bytes by padding 0.  On receiving
frames smaller than 60 bytes, network driver takes it as a Rx error and
drop such frames.
Actually, maybe it's a bug of tun driver, it should extend small frames
before committing to qemu.
Yes, qemu ne2k DM does such work on receiving frames, now we make pcnet
DM do such check.
-Xin

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