Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Thomas Falcon <tlfalcon@linux.ibm.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org, drt@linux.vnet.ibm.com,
	sukadev@linux.vnet.ibm.com, ljp@linux.vnet.ibm.com,
	cforno12@linux.ibm.com
Subject: Re: [PATCH net-next 2/5] ibmvnic: Include documentation for ibmvnic sysfs files
Date: Mon, 31 Aug 2020 14:51:49 -0500	[thread overview]
Message-ID: <c4a785ea-d5bc-4178-994f-e426e6512496@linux.ibm.com> (raw)
In-Reply-To: <20200831120732.2fa09746@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>


On 8/31/20 2:07 PM, Jakub Kicinski wrote:
> On Mon, 31 Aug 2020 11:58:10 -0500 Thomas Falcon wrote:
>> Include documentation for existing ibmvnic sysfs files,
>> currently only for "failover," which is used to swap
>> the active hardware port to a backup port in redundant
>> backing hardware or failover configurations.
>>
>> Signed-off-by: Thomas Falcon <tlfalcon@linux.ibm.com>
>> ---
>>   Documentation/ABI/testing/sysfs-driver-ibmvnic | 14 ++++++++++++++
>>   1 file changed, 14 insertions(+)
>>   create mode 100644 Documentation/ABI/testing/sysfs-driver-ibmvnic
>>
>> diff --git a/Documentation/ABI/testing/sysfs-driver-ibmvnic b/Documentation/ABI/testing/sysfs-driver-ibmvnic
>> new file mode 100644
>> index 0000000..7fa2920
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/sysfs-driver-ibmvnic
>> @@ -0,0 +1,14 @@
>> +What:		/sys/devices/vio/<our device>/failover
>> +Date:		June 2017
>> +KernelVersion:	4.13
>> +Contact:	linuxppc-dev@lists.ozlabs.org
>> +Description:	If the ibmvnic device has been configured with redundant
>> +		physical NIC ports, the user may write "1" to the failover
>> +		file to trigger a device failover, which will reset the
>> +		ibmvnic device and swap to a backup physical port. If no
>> +		redundant physical port has been configured for the device,
>> +		the device will not reset and -EINVAL is returned. If anything
>> +		other than "1" is written to the file, -EINVAL will also be
>> +		returned.
>> +Users:		Any users of the ibmvnic driver which use redundant hardware
>> +		configurations.
> Could you elaborate what the failover thing is? Is it what net_failover
> does or something opposite? (you say "backup physical port" which
> sounds like physical port is a backup.. perhaps some IBM nomenclature
> there worth clarifying?)

Hi Jakub,

When creating a SRIOV VNIC device on a Power system, the user will 
specify one or more ports to use from physical NIC's available to the 
Power Hypervisor. These aren't visible to the Linux OS. In a failover 
configuration, the VNIC will have one active port and at least one other 
port in backup or standby mode. It's similar to the bonding driver's 
active-backup mode. If the hypervisor detects a problem with the active 
port, it will swap in the backup port and send a signal to the VNIC 
driver that it should reset, which is needed to activate the new port. 
There is also a mechanism through which the driver can force this 
operation in case the hypervisor does not detect an issue with the 
active port. This mechanism can be triggered by an administrator or with 
userspace tools through the 'failover' device file in sysfs.

Tom


  reply	other threads:[~2020-08-31 19:51 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-31 16:58 [PATCH net-next 0/5] ibmvnic: Report ACL settings in sysfs Thomas Falcon
2020-08-31 16:58 ` [PATCH net-next 1/5] ibmvnic: Create failover sysfs as part of an attribute group Thomas Falcon
2020-08-31 16:58 ` [PATCH net-next 2/5] ibmvnic: Include documentation for ibmvnic sysfs files Thomas Falcon
2020-08-31 19:07   ` Jakub Kicinski
2020-08-31 19:51     ` Thomas Falcon [this message]
2020-08-31 16:58 ` [PATCH net-next 3/5] ibmvnic: Remove ACL change indication definitions Thomas Falcon
2020-08-31 16:58 ` [PATCH net-next 4/5] ibmvnic: Reporting device ACL settings through sysfs Thomas Falcon
2020-09-02 21:51   ` Sukadev Bhattiprolu
2020-08-31 16:58 ` [PATCH net-next 5/5] ibmvnic: Provide documentation for ACL sysfs files Thomas Falcon
2020-08-31 19:26   ` Jakub Kicinski
2020-08-31 19:54     ` Thomas Falcon
2020-08-31 20:11       ` Jakub Kicinski
2020-08-31 21:44         ` Thomas Falcon
2020-08-31 22:00           ` Jakub Kicinski
2020-08-31 22:17             ` David Miller
2020-08-31 22:30               ` Thomas Falcon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=c4a785ea-d5bc-4178-994f-e426e6512496@linux.ibm.com \
    --to=tlfalcon@linux.ibm.com \
    --cc=cforno12@linux.ibm.com \
    --cc=drt@linux.vnet.ibm.com \
    --cc=kuba@kernel.org \
    --cc=ljp@linux.vnet.ibm.com \
    --cc=netdev@vger.kernel.org \
    --cc=sukadev@linux.vnet.ibm.com \
    --subject='Re: [PATCH net-next 2/5] ibmvnic: Include documentation for ibmvnic sysfs files' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).