Re: [PATCH] bnx2: Reset device during driver initialization

[Baoquan He <bhe@redhat.com>]

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?

About unity-mappings, are you saying it for intel iommu or amd iommu?
For amd iommu, I just skip call set_dte_entry calling during iommu
device init stage. Then in device init stage, namely __map_single, judge
and call set_dte_entry there to install the new pt_root into the related
dev table entry.

Thought you mention it, let me look into the unity-mappings of amd iommu
again.

Thanks a lot!