[PATCH v2 for-4.14 0/3] Remove the 1GB limitation on Rasberry Pi 4

Julien Grall posted 3 patches 1 week ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/xen tags/patchew/20200519172028.31169-1-julien@xen.org
Maintainers: Julien Grall <julien@xen.org>, Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>, Stefano Stabellini <sstabellini@kernel.org>
xen/arch/arm/domain_build.c                | 33 +++++++++++++---------
xen/arch/arm/platform.c                    |  5 ++++
xen/arch/arm/platforms/brcm-raspberry-pi.c |  1 +
xen/include/asm-arm/mm.h                   |  2 ++
xen/include/asm-arm/numa.h                 |  5 ----
xen/include/asm-arm/platform.h             |  2 ++
6 files changed, 29 insertions(+), 19 deletions(-)

[PATCH v2 for-4.14 0/3] Remove the 1GB limitation on Rasberry Pi 4

Posted by Julien Grall 1 week ago
From: Julien Grall <jgrall@amazon.com>

Hi all,

At the moment, a user who wants to boot Xen on the Raspberry Pi 4 can
only use the first GB of memory.

This is because several devices cannot DMA above 1GB but Xen doesn't
necessarily allocate memory for Dom0 below 1GB.

This small series is trying to address the problem by allowing a
platform to restrict where Dom0 banks are allocated.

This is also a candidate for Xen 4.14. Without it, a user will not be
able to use all the RAM on the Raspberry Pi 4.

This series has only be slighlty tested. I would appreciate more test on
the Rasbperry Pi 4 to confirm this removing the restriction.

Cheers,

Cc: paul@xen.org

Julien Grall (3):
  xen/arm: Allow a platform to override the DMA width
  xen/arm: Take into account the DMA width when allocating Dom0 memory
    banks
  xen/arm: plat: Allocate as much as possible memory below 1GB for dom0
    for RPI

 xen/arch/arm/domain_build.c                | 33 +++++++++++++---------
 xen/arch/arm/platform.c                    |  5 ++++
 xen/arch/arm/platforms/brcm-raspberry-pi.c |  1 +
 xen/include/asm-arm/mm.h                   |  2 ++
 xen/include/asm-arm/numa.h                 |  5 ----
 xen/include/asm-arm/platform.h             |  2 ++
 6 files changed, 29 insertions(+), 19 deletions(-)

-- 
2.17.1


Re: [PATCH v2 for-4.14 0/3] Remove the 1GB limitation on Rasberry Pi 4

Posted by Stefano Stabellini 1 week ago
On Tue, 19 May 2020, Julien Grall wrote:
> From: Julien Grall <jgrall@amazon.com>
> 
> Hi all,
> 
> At the moment, a user who wants to boot Xen on the Raspberry Pi 4 can
> only use the first GB of memory.
> 
> This is because several devices cannot DMA above 1GB but Xen doesn't
> necessarily allocate memory for Dom0 below 1GB.
> 
> This small series is trying to address the problem by allowing a
> platform to restrict where Dom0 banks are allocated.
> 
> This is also a candidate for Xen 4.14. Without it, a user will not be
> able to use all the RAM on the Raspberry Pi 4.
> 
> This series has only be slighlty tested. I would appreciate more test on
> the Rasbperry Pi 4 to confirm this removing the restriction.

You can add my reviewed-by to all patches in the series.