[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH v3 03/52] xen/arm: add an option to define Xen start address for Armv8-R



Hi,

On 26/06/2023 04:33, Penny Zheng wrote:
From: Wei Chen <wei.chen@xxxxxxx>

On Armv8-A, Xen has a fixed virtual start address (link address
too) for all Armv8-A platforms. In an MMU based system, Xen can
map its loaded address to this virtual start address. So, on
Armv8-A platforms, the Xen start address does not need to be
configurable. But on Armv8-R platforms, there is no MMU to map
loaded address to a fixed virtual address and different platforms
will have very different address space layout. So Xen cannot use
a fixed physical address on MPU based system and need to have it
configurable.

In this patch we introduce one Kconfig option for users to define
the default Xen start address for Armv8-R. Users can enter the
address in config time, or select the tailored platform config
file from arch/arm/configs.

And as we introduced Armv8-R to Xen, that means the existed Arm64
MMU based platforms should not be listed in Armv8-R platform
list, so we add !HAS_MPU dependency for these platforms.

From a brief look, this patch doesn't seem to be necessary in order to move the MMU code in separate files. Can you confirm?

If so can this be moved latter in the series? This is to allow the reviewers to focus on the MMU split as we discussed on the call today.

Cheers,

--
Julien Grall



 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.