(CC Wei as release manager)
On 10/11/16 08:30, Peng Fan wrote:
Hi Julien,
Hi Peng,
On Tue, Nov 01, 2016 at 02:42:06PM +0000, Julien Grall wrote:
Hi Peng,
Sorry for the late answer.
On 23/09/2016 03:55, Peng Fan wrote:
On AArch64 SoCs, some IPs may only have the capability to access
32 bits address space. The physical memory assigned for Dom0 maybe
not in 4GB address space, then the IPs will not work properly.
So need to allocate memory under 4GB for Dom0.
There is no restriction that how much lowmem needs to be allocated for
Dom0 ,so allocate lowmem as much as possible for Dom0.
This patch does not affect 32-bit domain, because Variable "lowmem" is
set to true at the beginning. If failed to allocate bank0 under 4GB,
need to panic for 32-bit domain, because 32-bit domain requires bank0
be allocated under 4GB.
For 64-bit domain, set "lowmem" to false, and continue allocating
memory from above 4GB.
Signed-off-by: Peng Fan <peng....@nxp.com>
Cc: Stefano Stabellini <sstabell...@kernel.org>
Cc: Julien Grall <julien.gr...@arm.com>
Reviewed-by: Julien Grall <julien.gr...@arm.com>
I am undecided whether this should be considered as a bug fix for Xen 4.8.
Are you aware of any ARM64 platform we currently support requiring allocation
of memory below 4GB?
I have no idea about this (:, but I think this is a bug fix. Alought current
supported platforms works well, users may choose 4.8 to support their
new platform which has the limitation to access 64bit address.
We are already late in the release process (rc5) for Xen 4.8. So we need
to be careful when including a bug fix and evaluate the pros and cons.
This patch is modifying the DOM0 memory layout for all 64-bit platforms.
So it could potentially break one of the platform we officially support
(see [1] for a non-exhaustive list). We don't have a test suite running
automatically for ARM64 at the moment (it is been working on), this
means that manual testing needs to be done. I am not aware of any
platform, in the list we supports, having this issue so I prefer to stay
on the safe side and defer this patch for Xen 4.9.
If a user cares about Xen 4.8 for their platforms, then they could
request the patch to be backported in Xen 4.8 after the release and
after extensive testing in staging.
Regards,
[1]
https://wiki.xenproject.org/wiki/Xen_ARM_with_Virtualization_Extensions#Hardware
Regards,
Peng.
Regards,
--
Julien Grall
--
Julien Grall
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