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Date: Wed, 5 Jun 2013 13:38:52 +0200
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20130605113852.GF30326@stefanha-thinkpad.muc.redhat.com>
References: <1370412828-15960-1-git-send-email-akong@redhat.com>
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In-Reply-To: <1370412828-15960-1-git-send-email-akong@redhat.com>
Subject: Re: [Qemu-devel] [PATCH] virtio-net: fix wrong size of vlan filter
 table
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To: Amos Kong <akong@redhat.com>
Cc: alex.williamson@redhat.com, qemu-devel@nongnu.org, mst@redhat.com

On Wed, Jun 05, 2013 at 02:13:48PM +0800, Amos Kong wrote:
> The MAX_VLAN is 4096, currently the vlan filter table has 512
> (4096 >> 3) entries, it's wrong.
> 
> One entry in vlan filter table can indicate 32(1 << 5) vlans,
> so the table should have 128 (4096 >> 5) entries.
> 
> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
> btw, it would be simple to use an uint32 number to indicate
> all vlans (same as igbvf). I found e1000 uses the same table.
> Nothing needs to change here, it would cause migration issue.
> ---
>  hw/net/virtio-net.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

I don't understand this patch.  memset() and qemu_put_buffer() work in
bytes, therefore MAX_VLAN >> 3.

MAX_VLAN >> 3 == MAX_VLAN / BITS_PER_BYTE
MAX_VLAN >> 5 == MAX_VLAN / (sizeof(uint32_t) * BITS_PER_BYTE)

What bug are you trying to fix?