netdev - Re: [net PATCH v2 2/8] fbnic: Gate AXI read/write enabling on FW mailbox

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <56e10559-9532-496c-af79-1ab4c8a8c8cc@intel.com>
Date: Tue, 6 May 2025 11:45:15 -0700
From: Jacob Keller <jacob.e.keller@...el.com>
To: Alexander Duyck <alexander.duyck@...il.com>, <netdev@...r.kernel.org>
CC: <davem@...emloft.net>, <kuba@...nel.org>, <pabeni@...hat.com>,
	<horms@...nel.org>
Subject: Re: [net PATCH v2 2/8] fbnic: Gate AXI read/write enabling on FW
 mailbox



On 5/6/2025 8:59 AM, Alexander Duyck wrote:
> From: Alexander Duyck <alexanderduyck@...com>
> 
> In order to prevent the device from throwing spurious writes and/or reads
> at us we need to gate the AXI fabric interface to the PCIe until such time
> as we know the FW is in a known good state.
> 
> To accomplish this we use the mailbox as a mechanism for us to recognize
> that the FW has acknowledged our presence and is no longer sending any
> stale message data to us.
> 
> We start in fbnic_mbx_init by calling fbnic_mbx_reset_desc_ring function,
> disabling the DMA in both directions, and then invalidating all the
> descriptors in each ring.
> 
> We then poll the mailbox in fbnic_mbx_poll_tx_ready and when the interrupt
> is set by the FW we pick it up and mark the mailboxes as ready, while also
> enabling the DMA.
> 
> Once we have completed all the transactions and need to shut down we call
> into fbnic_mbx_clean which will in turn call fbnic_mbx_reset_desc_ring for
> each ring and shut down the DMA and once again invalidate the descriptors.
> 
> Fixes: 3646153161f1 ("eth: fbnic: Add register init to set PCIe/Ethernet device config")
> Fixes: da3cde08209e ("eth: fbnic: Add FW communication mechanism")
> Signed-off-by: Alexander Duyck <alexanderduyck@...com>
> Reviewed-by: Simon Horman <horms@...nel.org>
> ---
Reviewed-by: Jacob Keller <jacob.e.keller@...el.com>