lkml.org 
[lkml]   [2016]   [Sep]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] bnx2: Reset device during driver initialization
Hi Joerg,

On 09/09/16 at 10:41am, Joerg Roedel wrote:
>
> Hi Baoquan,
>
> On Fri, Sep 09, 2016 at 04:22:25PM +0800, Baoquan He wrote:
> > Recently I tried to fix the kdump failure in amd iommu system again, and
> > now the latest code works, IO_PAGE_FAULT can't be seen any more. But on
> > several amd iommu system with bnx2 NIC, always IO_PAGE_FAULT will be
> > printed out. After investegating I found out bnx2 driver doesn't reset
> > hardware/reg like other pci device, it does the reset job in bnx2_open
> > which is the net device up stage. So with this patch the IO_PAGE_FAULT
> > is away too on the system with bnx2 NIC. I will
> >
> > However when I got a intel system with vt-d and bnx2 NIC, kdump works
> > well, and no any error message can be seen. From code it clearly shows
> > the domain assignment is done in __intel_map_single, at this time bnx2
> > driver hasn't reset device, the on-flight DMA should still exist. Do you
> > have any idea on this? Or I missed anything? I also deferred the
> > set_dte_entry calling to __map_single calling, the principal should be
> > similar.
>
> Did you make sure that all unity-mappings are in place in the newly
> assigned domain for the bnx2 device before domains are switched?

What I am doing is that in iommu driver init stage anything will keep
going forware as it does in normal kernel except for set_dte_entry
calling. If in kdump kernel and in iommu init stage, just return
directly at the beginning of set_dte_entry.

For identity mapping, the pass through handling will do everything but
return from the beginning of set_dte_entry too. Since it need install
pte_root into dev table entry too though its pte_root is NULL. The unity
mapping range only does iova reservation. It doesn't do dev table entry
handling before device driver init.

So unity mappings should be OK.

Thanks a lot!

Baoquan

\
 
 \ /
  Last update: 2016-09-17 09:58    [W:0.342 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site