[Qemu-devel] FW: [Xen-devel] [PATCH] Fox for pcnet device model data corruption

[Kamble, Nitin A]

Thanks & Regards,
Nitin
--------------------------------------------------
Open Source Technology Center, Intel Corp



-----Original Message-----
From: address@hidden on behalf of Kamble, Nitin A
Sent: Fri 2/24/2006 4:10 PM
To: address@hidden
Cc: Ian Pratt
Subject: [Xen-devel] [PATCH] Fox for pcnet device model data corruption
 


Thanks & Regards,
Nitin
--------------------------------------------------
Open Source Technology Center, Intel Corp



-----Original Message-----
From: address@hidden on behalf of Kamble, Nitin A
Sent: Fri 2/24/2006 4:10 PM
To: address@hidden
Cc: Ian Pratt
Subject: [Xen-devel] [PATCH] Fox for pcnet device model data corruption
 
Hi Antony,
  This patch is also application to your pcnet patch for qemu. There is one 
more patch to fix the packet size if it is too small for the pcnet, if you have 
not see it, let me know. 

Thanks & Regards,
Nitin
--------------------------------------------------
Open Source Technology Center, Intel Corp



-----Original Message-----
From: address@hidden on behalf of Kamble, Nitin A
Sent: Fri 2/24/2006 4:10 PM
To: address@hidden
Cc: Ian Pratt
Subject: [Xen-devel] [PATCH] Fox for pcnet device model data corruption
 
Hi Ian,

   The attached patch fixes pcnet data corruption for VMX guests as reported by 
you.

All the packets go through the qemu generic packet interface to the specific 
device model. In this case the device model is pcnet.

   The pcnet device model receiver is registered with it like this.

qemu_add_read_packet(nd, pcnet_can_receive, pcnet_receive, d);

   pcnet_can_receive function is used to tell the generic qemu framework that 
the DM can receive packets. It is suppose block incoming packets in the cases 
such as when the pcnet driver is not yet started by the OS or pcnet device is 
suspended or stopped by the OS or it is not ready to receive more packets.

    When the traffic is heavy on the DM, its receive rings can get filled up, 
and it will has to drop the receiving packets. This patch detects this 
situation in the pcnet_can_receive() function and avoids dropping of packets. 
This mechanism is working as a bandwidth handshaking between device model and 
the sender. Dm is saying send me up to the rate at which I can handle it.

 

Signed-Off-By: Nitin A Kamble <address@hidden>

 

Thanks & Regards,

Nitin

-----------------------------------------------------------------------------------

Open Source Technology Center, Intel Corp

pcnet_corruption_fix.patch
Description: pcnet_corruption_fix.patch

ATT1497362.txt
Description: ATT1497362.txt