README.md | 21 ++++++++ scripts/uboot-script-gen | 7 +++ scripts/xen_dt_domu | 103 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 131 insertions(+)
Add DOMU_STATIC_EVTCHNS[number]="local_port remote_dom_idx remote_port; ..."
configuration file string option specifying the static event channel
definitions for domain.
For the following example:
DOMU_STATIC_EVTCHNS[0]="10 1 11; 12 1 13"
DOMU_STATIC_EVTCHNS[1]="11 0 10; 13 0 12"
it generates:
fdt mknod /chosen/domU0 evtchn@10
fdt set /chosen/domU0/evtchn@10 phandle <0xfffffffe>
fdt set /chosen/domU0/evtchn@10 compatible "xen,evtchn-v1"
fdt set /chosen/domU0/evtchn@10 xen,evtchn <10 0xfffffffd>
fdt mknod /chosen/domU0 evtchn@12
fdt set /chosen/domU0/evtchn@12 phandle <0xfffffffc>
fdt set /chosen/domU0/evtchn@12 compatible "xen,evtchn-v1"
fdt set /chosen/domU0/evtchn@12 xen,evtchn <12 0xfffffffb>
...
fdt mknod /chosen/domU1 evtchn@11
fdt set /chosen/domU1/evtchn@11 phandle <0xfffffffd>
fdt set /chosen/domU1/evtchn@11 compatible "xen,evtchn-v1"
fdt set /chosen/domU1/evtchn@11 xen,evtchn <11 0xfffffffe>
fdt mknod /chosen/domU1 evtchn@13
fdt set /chosen/domU1/evtchn@13 phandle <0xfffffffb>
fdt set /chosen/domU1/evtchn@13 compatible "xen,evtchn-v1"
fdt set /chosen/domU1/evtchn@13 xen,evtchn <13 0xfffffffc>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
---
V2:
- completely rework based on Stefano-s suggestion at:
https://patchew.org/Xen/20250929180746.1881872-1-oleksandr._5Ftyshchenko@epam.com/
---
---
README.md | 21 ++++++++
scripts/uboot-script-gen | 7 +++
scripts/xen_dt_domu | 103 +++++++++++++++++++++++++++++++++++++++
3 files changed, 131 insertions(+)
diff --git a/README.md b/README.md
index 7b68cf5..2efac97 100644
--- a/README.md
+++ b/README.md
@@ -218,6 +218,27 @@ Where:
DOMU_VCPU_HARD_AFFINITY[number,1]="3"
```
+- DOMU_STATIC_EVTCHNS[number]="local_port remote_dom_idx remote_port; ..."
+ if specified, this parameter allows the configuration of static event channels
+ for inter-domain communication. Each entry in DOMU_STATIC_EVTCHNS[number]
+ specifies one or more event channels for a particular domain.
+ The configuration format for each event channel definition is a set of
+ three values:
+ - local_port: The numeric port number for the local domain's endpoint.
+ This value must be unique within current domain.
+ - remote_dom_idx: The array index of the remote domain (e.g., if
+ connecting to DomU1, this would be `1`).
+ - remote_port: The numeric port number for the remote domain's endpoint.
+
+ Multiple event channel definitions for a single domain can be provided by
+ separating them with a semicolon (;).
+
+ Below is an example that creates two pairs of bidirectional channels between
+ two domains:
+ NUM_DOMUS=2
+ DOMU_STATIC_EVTCHNS[0]="10 1 11; 12 1 13"
+ DOMU_STATIC_EVTCHNS[1]="11 0 10; 13 0 12"
+
- DOMU_COLORS[number] specifies the colors (cache coloring) to be used
for the domain and is in the format startcolor-endcolor
diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
index 4f92610..e319de8 100755
--- a/scripts/uboot-script-gen
+++ b/scripts/uboot-script-gen
@@ -428,6 +428,8 @@ function xen_device_tree_editing()
fi
fi
+ xen_dt_build_evtchns_map
+
i=0
while test $i -lt $NUM_DOMUS
do
@@ -512,6 +514,11 @@ function xen_device_tree_editing()
xen_dt_domu_add_vcpu_nodes "/chosen/domU$i" $i ${DOMU_VCPUS[$i]}
+ if test "${DOMU_STATIC_EVTCHNS[$i]}"
+ then
+ xen_dt_domu_add_evtchns "/chosen/domU$i" "$i" "${DOMU_STATIC_EVTCHNS[$i]}"
+ fi
+
add_device_tree_kernel "/chosen/domU$i" "domU${i}_kernel" ${domU_kernel_addr[$i]} ${domU_kernel_size[$i]} "${DOMU_CMD[$i]}"
if test "${domU_ramdisk_addr[$i]}"
then
diff --git a/scripts/xen_dt_domu b/scripts/xen_dt_domu
index 8134896..45891b3 100644
--- a/scripts/xen_dt_domu
+++ b/scripts/xen_dt_domu
@@ -37,3 +37,106 @@ function xen_dt_domu_add_vcpu_nodes()
fi
done
}
+
+declare -A EVTCHN_ENDPOINT_TO_PHANDLE_MAP
+
+function xen_dt_build_evtchns_map()
+{
+ local def
+ local local_dom_idx
+ local local_port remote_dom_idx remote_port
+ local new_phandle
+ local local_key remote_key
+
+ for (( local_dom_idx=0; local_dom_idx<$NUM_DOMUS; local_dom_idx++ ))
+ do
+ local evtchn_str=${DOMU_STATIC_EVTCHNS[$local_dom_idx]}
+ if test -z "$evtchn_str"
+ then
+ continue
+ fi
+
+ IFS=';' read -ra evtchn_defs <<< "$evtchn_str"
+
+ # Loop over each definition and process both endpoints of the connection
+ for def in "${evtchn_defs[@]}"
+ do
+ read -r local_port remote_dom_idx remote_port <<< "$def"
+ if test -z "$local_port" || test -z "$remote_dom_idx" || test -z "$remote_port"
+ then
+ echo "Malformed evtchn definition: '$def' in DOMU_STATIC_EVTCHNS[$local_dom_idx]"
+ cleanup_and_return_err
+ fi
+
+ # Define keys for both endpoints of the connection
+ local_key="$local_dom_idx,$local_port"
+ remote_key="$remote_dom_idx,$remote_port"
+
+ if [[ "$local_key" == "$remote_key" ]]; then
+ echo "Invalid evtchn definition: '$def' in DOMU_STATIC_EVTCHNS[$local_dom_idx]"
+ cleanup_and_return_err
+ fi
+
+ # For each key, if it is not already in our map, assign it a new phandle
+ if [[ ! -v EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$local_key] ]]
+ then
+ get_next_phandle new_phandle
+ EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$local_key]=$new_phandle
+ echo "Local endpoint '$local_key' is assigned phandle '$new_phandle'"
+ fi
+
+ if [[ ! -v EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$remote_key] ]]
+ then
+ get_next_phandle new_phandle
+ EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$remote_key]=$new_phandle
+ echo "Remote endpoint '$remote_key' is assigned phandle '$new_phandle'"
+ fi
+ done
+ done
+}
+
+function xen_dt_domu_add_evtchns()
+{
+ # $1 - dt path
+ local path=$1
+ # $2 - index of the current domain
+ local local_dom_idx=$2
+ # $3 - full event channel definition string
+ local evtchn_str=$3
+
+ local def
+ local local_port remote_dom_idx remote_port
+ local local_phandle remote_phandle
+ local local_key remote_key
+
+ IFS=';' read -ra evtchn_defs <<< "$evtchn_str"
+
+ # Loop over each definition and create a node for it
+ for def in "${evtchn_defs[@]}"
+ do
+ read -r local_port remote_dom_idx remote_port <<< "$def"
+ if test -z "$local_port" || test -z "$remote_dom_idx" || test -z "$remote_port"
+ then
+ echo "Malformed evtchn definition: '$def' in DOMU_STATIC_EVTCHNS[$local_dom_idx]"
+ cleanup_and_return_err
+ fi
+
+ # Re-create the keys for both endpoints of the connection to look up the phandles
+ local_key="$local_dom_idx,$local_port"
+ remote_key="$remote_dom_idx,$remote_port"
+
+ local_phandle=${EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$local_key]}
+ remote_phandle=${EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$remote_key]}
+
+ if test -z "$local_phandle" || test -z "$remote_phandle"
+ then
+ echo "Could not find phandle for endpoint '$local_key' or '$remote_key'"
+ cleanup_and_return_err
+ fi
+
+ dt_mknode "${path}" "evtchn@$local_port"
+ dt_set "${path}/evtchn@$local_port" "phandle" "hex" "$local_phandle"
+ dt_set "${path}/evtchn@$local_port" "compatible" "str" "xen,evtchn-v1"
+ dt_set "${path}/evtchn@$local_port" "xen,evtchn" "hex" "$local_port $remote_phandle"
+ done
+}
--
2.34.1On Tue, 30 Sep 2025, Oleksandr Tyshchenko wrote:
> Add DOMU_STATIC_EVTCHNS[number]="local_port remote_dom_idx remote_port; ..."
> configuration file string option specifying the static event channel
> definitions for domain.
>
> For the following example:
> DOMU_STATIC_EVTCHNS[0]="10 1 11; 12 1 13"
> DOMU_STATIC_EVTCHNS[1]="11 0 10; 13 0 12"
>
> it generates:
> fdt mknod /chosen/domU0 evtchn@10
> fdt set /chosen/domU0/evtchn@10 phandle <0xfffffffe>
> fdt set /chosen/domU0/evtchn@10 compatible "xen,evtchn-v1"
> fdt set /chosen/domU0/evtchn@10 xen,evtchn <10 0xfffffffd>
> fdt mknod /chosen/domU0 evtchn@12
> fdt set /chosen/domU0/evtchn@12 phandle <0xfffffffc>
> fdt set /chosen/domU0/evtchn@12 compatible "xen,evtchn-v1"
> fdt set /chosen/domU0/evtchn@12 xen,evtchn <12 0xfffffffb>
> ...
> fdt mknod /chosen/domU1 evtchn@11
> fdt set /chosen/domU1/evtchn@11 phandle <0xfffffffd>
> fdt set /chosen/domU1/evtchn@11 compatible "xen,evtchn-v1"
> fdt set /chosen/domU1/evtchn@11 xen,evtchn <11 0xfffffffe>
> fdt mknod /chosen/domU1 evtchn@13
> fdt set /chosen/domU1/evtchn@13 phandle <0xfffffffb>
> fdt set /chosen/domU1/evtchn@13 compatible "xen,evtchn-v1"
> fdt set /chosen/domU1/evtchn@13 xen,evtchn <13 0xfffffffc>
>
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
> ---
> V2:
> - completely rework based on Stefano-s suggestion at:
> https://patchew.org/Xen/20250929180746.1881872-1-oleksandr._5Ftyshchenko@epam.com/
> ---
> ---
> README.md | 21 ++++++++
> scripts/uboot-script-gen | 7 +++
> scripts/xen_dt_domu | 103 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 131 insertions(+)
>
> diff --git a/README.md b/README.md
> index 7b68cf5..2efac97 100644
> --- a/README.md
> +++ b/README.md
> @@ -218,6 +218,27 @@ Where:
> DOMU_VCPU_HARD_AFFINITY[number,1]="3"
> ```
>
> +- DOMU_STATIC_EVTCHNS[number]="local_port remote_dom_idx remote_port; ..."
> + if specified, this parameter allows the configuration of static event channels
> + for inter-domain communication. Each entry in DOMU_STATIC_EVTCHNS[number]
> + specifies one or more event channels for a particular domain.
> + The configuration format for each event channel definition is a set of
> + three values:
> + - local_port: The numeric port number for the local domain's endpoint.
> + This value must be unique within current domain.
> + - remote_dom_idx: The array index of the remote domain (e.g., if
> + connecting to DomU1, this would be `1`).
> + - remote_port: The numeric port number for the remote domain's endpoint.
> +
> + Multiple event channel definitions for a single domain can be provided by
> + separating them with a semicolon (;).
> +
> + Below is an example that creates two pairs of bidirectional channels between
> + two domains:
> + NUM_DOMUS=2
> + DOMU_STATIC_EVTCHNS[0]="10 1 11; 12 1 13"
> + DOMU_STATIC_EVTCHNS[1]="11 0 10; 13 0 12"
> +
> - DOMU_COLORS[number] specifies the colors (cache coloring) to be used
> for the domain and is in the format startcolor-endcolor
>
> diff --git a/scripts/uboot-script-gen b/scripts/uboot-script-gen
> index 4f92610..e319de8 100755
> --- a/scripts/uboot-script-gen
> +++ b/scripts/uboot-script-gen
> @@ -428,6 +428,8 @@ function xen_device_tree_editing()
> fi
> fi
>
> + xen_dt_build_evtchns_map
> +
> i=0
> while test $i -lt $NUM_DOMUS
> do
> @@ -512,6 +514,11 @@ function xen_device_tree_editing()
>
> xen_dt_domu_add_vcpu_nodes "/chosen/domU$i" $i ${DOMU_VCPUS[$i]}
>
> + if test "${DOMU_STATIC_EVTCHNS[$i]}"
> + then
> + xen_dt_domu_add_evtchns "/chosen/domU$i" "$i" "${DOMU_STATIC_EVTCHNS[$i]}"
> + fi
> +
> add_device_tree_kernel "/chosen/domU$i" "domU${i}_kernel" ${domU_kernel_addr[$i]} ${domU_kernel_size[$i]} "${DOMU_CMD[$i]}"
> if test "${domU_ramdisk_addr[$i]}"
> then
> diff --git a/scripts/xen_dt_domu b/scripts/xen_dt_domu
> index 8134896..45891b3 100644
> --- a/scripts/xen_dt_domu
> +++ b/scripts/xen_dt_domu
> @@ -37,3 +37,106 @@ function xen_dt_domu_add_vcpu_nodes()
> fi
> done
> }
> +
> +declare -A EVTCHN_ENDPOINT_TO_PHANDLE_MAP
> +
> +function xen_dt_build_evtchns_map()
> +{
> + local def
> + local local_dom_idx
> + local local_port remote_dom_idx remote_port
> + local new_phandle
> + local local_key remote_key
> +
> + for (( local_dom_idx=0; local_dom_idx<$NUM_DOMUS; local_dom_idx++ ))
> + do
> + local evtchn_str=${DOMU_STATIC_EVTCHNS[$local_dom_idx]}
> + if test -z "$evtchn_str"
> + then
> + continue
> + fi
> +
> + IFS=';' read -ra evtchn_defs <<< "$evtchn_str"
> +
> + # Loop over each definition and process both endpoints of the connection
> + for def in "${evtchn_defs[@]}"
> + do
> + read -r local_port remote_dom_idx remote_port <<< "$def"
> + if test -z "$local_port" || test -z "$remote_dom_idx" || test -z "$remote_port"
> + then
> + echo "Malformed evtchn definition: '$def' in DOMU_STATIC_EVTCHNS[$local_dom_idx]"
> + cleanup_and_return_err
> + fi
> +
> + # Define keys for both endpoints of the connection
> + local_key="$local_dom_idx,$local_port"
> + remote_key="$remote_dom_idx,$remote_port"
> +
> + if [[ "$local_key" == "$remote_key" ]]; then
> + echo "Invalid evtchn definition: '$def' in DOMU_STATIC_EVTCHNS[$local_dom_idx]"
> + cleanup_and_return_err
> + fi
> +
> + # For each key, if it is not already in our map, assign it a new phandle
> + if [[ ! -v EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$local_key] ]]
> + then
> + get_next_phandle new_phandle
> + EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$local_key]=$new_phandle
> + echo "Local endpoint '$local_key' is assigned phandle '$new_phandle'"
> + fi
> +
> + if [[ ! -v EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$remote_key] ]]
> + then
> + get_next_phandle new_phandle
> + EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$remote_key]=$new_phandle
> + echo "Remote endpoint '$remote_key' is assigned phandle '$new_phandle'"
> + fi
> + done
> + done
> +}
> +
> +function xen_dt_domu_add_evtchns()
> +{
> + # $1 - dt path
> + local path=$1
> + # $2 - index of the current domain
> + local local_dom_idx=$2
> + # $3 - full event channel definition string
> + local evtchn_str=$3
> +
> + local def
> + local local_port remote_dom_idx remote_port
> + local local_phandle remote_phandle
> + local local_key remote_key
> +
> + IFS=';' read -ra evtchn_defs <<< "$evtchn_str"
> +
> + # Loop over each definition and create a node for it
> + for def in "${evtchn_defs[@]}"
> + do
> + read -r local_port remote_dom_idx remote_port <<< "$def"
> + if test -z "$local_port" || test -z "$remote_dom_idx" || test -z "$remote_port"
> + then
> + echo "Malformed evtchn definition: '$def' in DOMU_STATIC_EVTCHNS[$local_dom_idx]"
> + cleanup_and_return_err
> + fi
> +
> + # Re-create the keys for both endpoints of the connection to look up the phandles
> + local_key="$local_dom_idx,$local_port"
> + remote_key="$remote_dom_idx,$remote_port"
> +
> + local_phandle=${EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$local_key]}
> + remote_phandle=${EVTCHN_ENDPOINT_TO_PHANDLE_MAP[$remote_key]}
> +
> + if test -z "$local_phandle" || test -z "$remote_phandle"
> + then
> + echo "Could not find phandle for endpoint '$local_key' or '$remote_key'"
> + cleanup_and_return_err
> + fi
> +
> + dt_mknode "${path}" "evtchn@$local_port"
> + dt_set "${path}/evtchn@$local_port" "phandle" "hex" "$local_phandle"
> + dt_set "${path}/evtchn@$local_port" "compatible" "str" "xen,evtchn-v1"
> + dt_set "${path}/evtchn@$local_port" "xen,evtchn" "hex" "$local_port $remote_phandle"
> + done
> +}
> --
> 2.34.1
>
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