From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: Re: HVM dropped packets
Date: Wed, 26 Aug 2009 10:29:50 +0100
Message-ID: <alpine.DEB.2.00.0908261029120.18554@kaball-desktop>
References: <C6BAA899.12F42%keir.fraser@eu.citrix.com>
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To: Keir Fraser <keir.fraser@eu.citrix.com>
Cc: Xen-devel <xen-devel@lists.xensource.com>, Nathan Stratton <nathan@robotics.net>
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On Wed, 26 Aug 2009, Keir Fraser wrote:
> On 26/08/2009 08:45, "Nathan Stratton" <nathan@robotics.net> wrote:
> 
> >> I bet the drops are caused by the low performance of Qemu nic _emulation_.
> > 
> > Does one emulate better then the rest?
> 
> e1000 is probably faster than the rest due to a more efficient hardware
> interface better suited to emulation. You may still get receiver overruns
> though (which I think was the source of the drops you were seeing?). That's
> simply the host receiving packets faster than they can get stuffed through
> the emulated interface.

ON this note KVM people stated that the emulated e1000 gives 90% of virtio
performances.