Re: [XEN v5] xen/arm64: io: Decode ldr/str post-indexing instructions

[Julien Grall <julien@xxxxxxx>]

Hi,

On 01/02/2022 19:06, Ayan Kumar Halder wrote:
> > As you pointed out previously, the field SAS (Syndrome Access Size) is 
> > invalid when the ISV=0. So the decoding needs to be done *before* we 
> > select the IOREQ server.
> > But as I said, this would result to decode the instruciton when this 
> > is not necessary. This is where Stefano's suggestion in [1] is useful.
> > For ISV=0, it will be a lot more common to trap because of a P2M 
> > translation fault (of the MMIO is not mapped). So we should call that 
> > first and then, if it still not resolved, try to decode the instruction.
> > With that in place, you are avoiding the issue in try_fwd_ioserv().
> >
> > Can you please coordinate with Stefano?
> Can you let me know which suggestion Julien is referring here ?
>
> [1] does not point to a valid url.
This is a message-id. They are unique, so you can easily find the 
message on public archives (e.g. lore.kernel.org) or in your inbox.
I tend to use lore.kernel.org for the archives. The URL looks like:

https://lore.kernel.org/<ml>/<message-id>

In your case, <ml> would be xen-devel (they also archives may other MLs) 
and the <message-id> would be the one I put in [1].
The message-id can be really useful if you use it in combination of 
tools like b4 [1]. With a single ID, it allows you to pull a series, 
fetch tags and then you can apply with 'git am'.
Cheers,

[1] 
https://people.kernel.org/monsieuricon/introducing-b4-and-patch-attestation
--
Julien Grall