From: David Vrabel <david.vrabel@citrix•com>
To: Vitaly Kuznetsov <vkuznets@redhat•com>, <netdev@vger•kernel.org>
Cc: Juergen Gross <jgross@suse•com>,
Patrick Talbert <ptalbert@redhat•com>,
<linux-kernel@vger•kernel.org>,
David Vrabel <david.vrabel@citrix•com>,
<xen-devel@lists•xenproject.org>,
Boris Ostrovsky <boris.ostrovsky@oracle•com>
Subject: Re: [Xen-devel] [PATCH net-next] xen-netfront: avoid packet loss when ethernet header crosses page boundary
Date: Mon, 22 Aug 2016 17:55:23 +0100 [thread overview]
Message-ID: <57BB2E7B.5040303@citrix.com> (raw)
In-Reply-To: <1471880577-21380-1-git-send-email-vkuznets@redhat.com>
On 22/08/16 16:42, Vitaly Kuznetsov wrote:
>
> I see two ways to fix the issue:
> - Change the 'wire' protocol between netfront and netback to start keeping
> the original SKB structure. We'll have to add a flag indicating the fact
> that the particular request is a part of the original linear part and not
> a frag. We'll need to know the length of the linear part to pre-allocate
> memory.
I don't think there needs to be a protocol change. I think the check in
netback is bogus -- it's the total packet length that must be >
HLEN_ETH. The upper layers will pull any headers from the frags as
needed (or if necessary, netback could pull a minimum amount).
There's no need to preserve the skb layout (e.g., look how the to-guest
direction we do not do this).
David
next prev parent reply other threads:[~2016-08-22 16:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-22 15:42 [PATCH net-next] xen-netfront: avoid packet loss when ethernet header crosses page boundary Vitaly Kuznetsov
2016-08-22 16:55 ` David Vrabel [this message]
2016-08-23 18:51 ` Vitaly Kuznetsov
2016-08-29 10:28 ` [Xen-devel] " Vitaly Kuznetsov
2016-09-09 13:39 ` Vitaly Kuznetsov
2016-09-09 13:41 ` David Vrabel
2016-09-12 11:52 ` Vitaly Kuznetsov
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