netdev - Re: [PATCH net-next v1] bnxt: fix bnxt_get_avail

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: <eb39f73b-d1a5-4bca-b1b9-c4f6715b6a10@davidwei.uk>
Date: Thu, 25 Apr 2024 16:40:05 -0700
From: David Wei <dw@...idwei.uk>
To: Michael Chan <michael.chan@...adcom.com>
Cc: netdev@...r.kernel.org, Pavan Chebbi <pavan.chebbi@...adcom.com>,
 Andy Gospodarek <andrew.gospodarek@...adcom.com>,
 Jakub Kicinski <kuba@...nel.org>, "David S. Miller" <davem@...emloft.net>,
 Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>
Subject: Re: [PATCH net-next v1] bnxt: fix bnxt_get_avail_msix() returning
 negative values

On 2024-04-25 3:25 pm, Michael Chan wrote:
> On Thu, Apr 25, 2024 at 2:26 PM David Wei <dw@...idwei.uk> wrote:
>>
>> Current net-next/main does not boot for older chipsets e.g. Stratus.
>>
>> Sample dmesg:
>> [   11.368315] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): Able to reserve only 0 out of 9 requested RX rings
>> [   11.390181] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): Unable to reserve tx rings
>> [   11.438780] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): 2nd rings reservation failed.
>> [   11.487559] bnxt_en 0000:02:00.0 (unnamed net_device) (uninitialized): Not enough rings available.
>> [   11.506012] bnxt_en 0000:02:00.0: probe with driver bnxt_en failed with error -12
>>
>> This is caused by bnxt_get_avail_msix() returning a negative value for
>> these chipsets not using the new resource manager i.e. !BNXT_NEW_RM.
>> This in turn causes hwr.cp in __bnxt_reserve_rings() to be set to 0.
>>
>> In the current call stack, __bnxt_reserve_rings() is called from
>> bnxt_set_dflt_rings() before bnxt_init_int_mode(). Therefore,
>> bp->total_irqs is always 0 and for !BNXT_NEW_RM bnxt_get_avail_msix()
>> always returns a negative number.
> 
> Thanks for the patch.  I'm still trying to understand the flow on this
> older NIC.
> 
> If BNXT_NEW_RM() is not true, shouldn't bnxt_need_reserve_ring()
> return false from the top of __bnxt_reserve_rings()?
> 
> Ah perhaps this NIC is using hwrm_spec_code >= 0x10601 and
> !BNXT_NEW_RM().  In that case bnxt_need_reserve_rings() will return
> true because we have to reserve only the TX rings.  Let me review this
> code path some more.  Thanks again.

Yes, hwrm_spec_code >= 0x10601 and the first conditional in
bnxt_need_reserve_rings() returns true.