Re: [ImageBuilder][PATCH] uboot-script-gen: Add support for specifying domain P2M pool size

["Halder, Ayan Kumar" <ayankuma@xxxxxxx>]

Hi Oleksandr,

On 20/01/2026 18:23, Oleksandr Tyshchenko wrote:
> The DOMU_P2M_MEM_MB configuration option is used to specify
> the amount of megabytes of RAM used for the domain P2M pool.
> It allows users to manually define the memory size reserved for
> P2M structures in non-hardware domains, overriding the default
> value calculated by Xen.
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Reviewed-by: Ayan Kumar Halder <ayan.kumar.halder@xxxxxxx>

with a question

> ---
>   README.md                | 7 +++++++
>   scripts/uboot-script-gen | 5 +++++
>   2 files changed, 12 insertions(+)
>
> diff --git a/README.md b/README.md
> index 983cbbc..c7ae98e 100644
> --- a/README.md
> +++ b/README.md
> @@ -203,6 +203,13 @@ Where:
>     NOTE that with this option, user needs to manually set xen,passthrough
>     in xen.dtb.
>   
> +- DOMU_P2M_MEM_MB[number] is optional 32-bit integer specifying the amount
> +  of megabytes of RAM used for the domain P2M pool. If not set, the default
> +  size is calculated by Xen.
> +  Note that the P2M pool is used to allocate pages for P2M structures for
> +  non-hardware domains. For the hardware domain, P2M pages are allocated
> +  directly from the heap.
> +
>   - DOMU_MEM[number] is the amount of memory for the VM in MB, default 512MB
>   
>   - DOMU_VCPUS[number] is the number of vcpus for the VM, default 1
> diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
> index d18ac55..0c86c2d 100755
> --- a/scripts/uboot-script-gen
> +++ b/scripts/uboot-script-gen
> @@ -514,6 +514,11 @@ function xen_device_tree_editing()
>               dt_set "/chosen/domU$i" "passthrough" "str" "enabled"
>           fi
>   
> +        if test -n "${DOMU_P2M_MEM_MB[$i]}"
> +        then
> +            dt_set "/chosen/domU$i" "xen,domain-p2m-mem-mb"
Was this property recently introduced in Xen ? If so, it may be good to 
refer Xen's commit id.
- Ayan