Linux Virtualization - Oct 2021 - [PATCH v5 12/16] PCI: Add pci_iomap_host_shared(), pci_iomap_host_shared_range()

On 10/11/2021 12:58 AM, Christoph Hellwig wrote:
> Just as last time:  This does not make any sense.  ioremap is shared
> by definition.
It's not necessarily shared with the host for confidential computing: 
for example BIOS mappings definitely should not be shared, but they're 
using ioremap today.

But if you have a better term please propose something. I tried to 
clarify it with "shared_host", but I don't know a better term.


-Andi

On Mon, Oct 11, 2021 at 10:23:00AM -0700, Andi Kleen
wrote:
> 
> On 10/11/2021 12:58 AM, Christoph Hellwig wrote:
> > Just as last time:  This does not make any sense.  ioremap is shared
> > by definition.
> 
> It's not necessarily shared with the host for confidential computing:
for
> example BIOS mappings definitely should not be shared, but they're
using
> ioremap today.
That just needs to be fixed.
> But if you have a better term please propose something. I tried to clarify
> it with "shared_host", but I don't know a better term.
> 
> 
> -Andi
> 

The reason we have trouble is that it's not clear what does the API mean
outside the realm of TDX.
If we really, truly want an API that says "ioremap and it's a hardened
driver" then I guess ioremap_hardened_driver is what you want.

-- 
MST