From: Wei Yang <weiyang@linux•vnet.ibm.com>
To: Or Gerlitz <ogerlitz@mellanox•com>
Cc: davem@davemloft•net, netdev@vger•kernel.org, amirv@mellanox•com,
weiyang@linux•vnet.ibm.com, bhelgaas@google•com,
Jack Morgenstein <jackm@dev•mellanox.co.il>
Subject: Re: [PATCH net] net/mlx4_core: Fix Oops on reboot when SRIOV VFs are probed into the Host
Date: Mon, 2 Jun 2014 22:29:47 +0800 [thread overview]
Message-ID: <20140602142947.GB28523@richard> (raw)
In-Reply-To: <1401619783-23659-1-git-send-email-ogerlitz@mellanox.com>
On Sun, Jun 01, 2014 at 01:49:43PM +0300, Or Gerlitz wrote:
>From: Jack Morgenstein <jackm@dev•mellanox.co.il>
>
>Commit befdf89 did not take into account the case where the Host
>driver is being unloaded. In this case, pci_get_drvdata for the VF
In my mind, unloading PF's driver when there is alive VFs is not allowed.
Quoted in driver code:
/* in SRIOV it is not allowed to unload the pf's
* driver while there are alive vf's */
if (mlx4_is_master(dev) && mlx4_how_many_lives_vf(dev))
printk(KERN_ERR "Removing PF when there are assigned VF's !!!\n");
Actually, I don't understand this restriction clearly. Maybe my understanding
of alive VF is not correct.
And in your code, unload PF's driver would call pci_disable_sriov() which will
destroy the VFs. While in your test, the VF's driver is still there?
>remove_one call may return NULL, so that dereferencing the priv
>struct results in a kernel oops.
Sorry for my poor mind, I still can't understand this situation.
Would you describe the situation more? You are unloading PF's driver in Host
at first, and then try to release the VF's driver?
>
>The fix is to also test that the dev pointer returned by
>pci_get_drvdata is non-NULL.
>
>Fixes: befdf89 ("preserve pcd_dev_data after __mlx4_remove_one()")
>Signed-off-by: Jack Morgenstein <jackm@dev•mellanox.co.il>
>Signed-off-by: Or Gerlitz <ogerlitz@mellanox•com>
>---
> drivers/net/ethernet/mellanox/mlx4/main.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
>diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
>index c187d74..a6ae089 100644
>--- a/drivers/net/ethernet/mellanox/mlx4/main.c
>+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
>@@ -2629,7 +2629,7 @@ static void __mlx4_remove_one(struct pci_dev *pdev)
> int pci_dev_data;
> int p;
>
>- if (priv->removed)
>+ if (!dev || priv->removed)
> return;
This fix looks good to me.
As I remembered, I had this check in my first version, but I removed the check
on dev based on the suggestion from Bjorn. Since I agreed that there is no
chance for dev to be NULL. Bjorn, seems we are not correct :(
>
> pci_dev_data = priv->pci_dev_data;
>--
>1.7.1
--
Richard Yang
Help you, Help me
next prev parent reply other threads:[~2014-06-02 14:29 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-01 10:49 [PATCH net] net/mlx4_core: Fix Oops on reboot when SRIOV VFs are probed into the Host Or Gerlitz
2014-06-01 16:41 ` Sergei Shtylyov
2014-06-01 19:59 ` Or Gerlitz
2014-06-02 14:29 ` Wei Yang [this message]
2014-06-02 16:10 ` Bjorn Helgaas
2014-06-03 0:58 ` David Miller
2014-06-03 2:00 ` Wei Yang
2014-06-03 8:15 ` Or Gerlitz
2014-06-03 8:40 ` Wei Yang
2014-06-04 9:50 ` Wei Yang
2014-06-06 2:52 ` Wei Yang
2014-06-08 9:18 ` Or Gerlitz
2014-06-08 9:16 ` Or Gerlitz
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