From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Igor Ryzhov <iryzhov@nfware.com>
Cc: dev@dpdk.org, David Marchand <david.marchand@6wind.com>,
"Liu, Yuanhan" <yuanhan.liu@intel.com>
Subject: Re: [dpdk-dev] rte_eth_dev_attach returns 0, although device is not attached
Date: Thu, 4 Aug 2016 14:21:57 +0100 [thread overview]
Message-ID: <57A34175.1040204@intel.com> (raw)
In-Reply-To: <0AB336DF-9C66-4826-BA17-EDE1F8D6A2EA@nfware.com>
On 8/4/2016 12:51 PM, Igor Ryzhov wrote:
> Hello Ferruh,
>
>> 4 авг. 2016 г., в 14:33, Ferruh Yigit <ferruh.yigit@intel.com> написал(а):
>>
>> Hi Igor,
>>
>> On 8/3/2016 5:58 PM, Igor Ryzhov wrote:
>>> Hello.
>>>
>>> Function rte_eth_dev_attach can return false positive result.
>>> It happens because rte_eal_pci_probe_one returns zero if no driver is found for the device:
>>> ret = pci_probe_all_drivers(dev);
>>> if (ret < 0)
>>> goto err_return;
>>> return 0;
>>> (pci_probe_all_drivers returns 1 in that case)
>>>
>>> For example, it can be easily reproduced by trying to attach virtio device, managed by kernel driver.
>>
>> You are right, and I did able to reproduce this issue with virtio as you
>> suggest.
>>
>> But I wonder why rte_eth_dev_get_port_by_addr() is not catching this.
>> Perhaps a dev->attached check needs to be added into this function.
With a second check, rte_eth_dev_get_port_by_addr() catches it if the
driver is missing.
But for virtio case, problem is not missing driver.
Problem is eth_virtio_dev_init() is returning a positive value on fail.
Call stack is:
rte_eal_pci_probe_one
pci_probe_all_drivers
rte_eal_pci_probe_one_driver
rte_eth_dev_init
eth_virtio_dev_init
So rte_eal_pci_probe_one_driver() also returns positive value, as no
driver found, and rte_eth_dev_get_port_by_addr() returns a valid
port_id, since rte_eth_dev_init() allocated an eth_dev.
Briefly, this can be fixed in virtio pmd, instead of eal pci.
>>
>>>
>>> I think it should be:
>>> ret = pci_probe_all_drivers(dev);
>>> if (ret)
>>> goto err_return;
>>> return 0;
>>
>> Your proposal looks good to me. Will you send a patch?
>
Original code silently ignores the if driver is missing for that dev,
although it is still questionable, I think we can keep this as it is.
> Patch sent.
Sorry for this, but can you please test with following modification in
virtio:
index 07d6449..c74eeee 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -1156,7 +1156,7 @@ eth_virtio_dev_init(struct rte_eth_dev *eth_dev)
if (pci_dev) {
ret = vtpci_init(pci_dev, hw, &dev_flags);
if (ret)
- return ret;
+ return -1;
}
/* Reset the device although not necessary at startup */
>
>>
>>> Best regards,
>>> Igor
>>>
>>
>
next prev parent reply other threads:[~2016-08-04 13:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-03 16:58 Igor Ryzhov
2016-08-04 11:33 ` Ferruh Yigit
2016-08-04 11:51 ` Igor Ryzhov
2016-08-04 13:21 ` Ferruh Yigit [this message]
2016-08-04 14:54 ` Igor Ryzhov
2016-08-04 15:47 ` Ferruh Yigit
2016-08-05 12:29 ` Bruce Richardson
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=57A34175.1040204@intel.com \
--to=ferruh.yigit@intel.com \
--cc=david.marchand@6wind.com \
--cc=dev@dpdk.org \
--cc=iryzhov@nfware.com \
--cc=yuanhan.liu@intel.com \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
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).