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 <[email protected]>
Reviewed-by: Ayan Kumar Halder <[email protected]>
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
