Re: [ImageBuilder][PATCH] uboot-script-gen: add ability to cfg vcpu hard affinity

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Mon, 17 Mar 2025, gragst.linux@xxxxxxxxx wrote:
> From: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
> 
> Add DOMU_VCPU_HARD_AFFINITY[number,vcpu] configuration file string option
> specifying the hard affinity configuration for the VM vCPU(vcpu) in DT.
> 
> The format is a comma-separated list of pCPUs or ranges of pCPUs. Ranges
> are hyphen-separated intervals (such as 0-4) and are inclusive on both
> sides. The numbers refer to logical pCPU ids.
> 
> For example:
> DOMU_VCPUS[0]="2"
> DOMU_VCPU_HARD_AFFINITY[0,0]="1"
> 
> will be reflected in domU0/vcpu0 DT node with "hard-affinity" set:
> vcpu0 {
>       hard-affinity = "1";
>       id = <0x00000000>;
>       compatible = "xen,vcpu";
> };
> 
> Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
> ---
>  README.md                | 11 +++++++++++
>  scripts/uboot-script-gen |  4 ++++
>  scripts/xen_dt_domu      | 39 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 54 insertions(+)
>  create mode 100644 scripts/xen_dt_domu
> 
> diff --git a/README.md b/README.md
> index 5b75018ea956..262022c665be 100644
> --- a/README.md
> +++ b/README.md
> @@ -186,6 +186,17 @@ Where:
>  
>  - DOMU_VCPUS[number] is the number of vcpus for the VM, default 1
>  
> +- DOMU_VCPU_HARD_AFFINITY[number,vcpu] optional, is the A string
> +  specifying the hard affinity configuration for the VM vCPU(vcpu):
> +  a comma-separated list of pCPUs or ranges of pCPUs is used.
> +  Ranges are hyphen-separated intervals (such as `0-4`) and are inclusive
> +  on both sides. The numbers refer to logical pCPU ids. Below is an example:
> +```
> +      DOMU_VCPUS[number]=2
> +      DOMU_VCPU_HARD_AFFINITY[number,0]="0-2"
> +      DOMU_VCPU_HARD_AFFINITY[number,1]="3"
> +```
> +
>  - 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 74e3b076910c..9229f9af567b 100755
> --- a/scripts/uboot-script-gen
> +++ b/scripts/uboot-script-gen
> @@ -392,6 +392,8 @@ function xen_device_tree_editing()
>              dt_set "/chosen/domU$i" "colors" "hex" "$(printf "0x%x" 
> $bitcolors)"
>          fi
>  
> +        xen_dt_domu_add_vcpu_nodes "/chosen/domU$i" $i ${DOMU_VCPUS[$i]}
> +
>          add_device_tree_kernel "/chosen/domU$i" ${domU_kernel_addr[$i]} 
> ${domU_kernel_size[$i]} "${DOMU_CMD[$i]}"
>          if test "${domU_ramdisk_addr[$i]}"
>          then
> @@ -1164,10 +1166,12 @@ fi
>  
>  check_depends
>  
> +declare -A DOMU_VCPU_HARD_AFFINITY
>  source "$cfg_file"
>  
>  SCRIPT_PATH=$(dirname "$0")
>  source "$SCRIPT_PATH/common"
> +source "$SCRIPT_PATH/xen_dt_domu"
>  
>  # command line overrides
>  LOAD_CMD=${load_opt:-$LOAD_CMD}
> diff --git a/scripts/xen_dt_domu b/scripts/xen_dt_domu
> new file mode 100644
> index 000000000000..e1cb2376c37e
> --- /dev/null
> +++ b/scripts/xen_dt_domu
> @@ -0,0 +1,39 @@
> +#!/bin/bash
> +
> +# uses:
> +# DOMU_VCPU_HARD_AFFINITY
> +function xen_dt_domu_add_vcpu_nodes()
> +{
> +    # $1 - dt path
> +    local path=$1
> +    # $2 - domain number
> +    local dom_num=$2
> +    # $3 - number of vcpus for the domain
> +    local vcpus=$3
> +    local hard_affinity=""
> +    local gen_vcpu=""
> +
> +    for (( vcpu=0; vcpu<${vcpus}; vcpu++ ))
> +    do
> +        gen_vcpu=""
> +        if test "${DOMU_VCPU_HARD_AFFINITY[$dom_num,$vcpu]}"
> +        then
> +            hard_affinity=${DOMU_VCPU_HARD_AFFINITY[$dom_num,$vcpu]}
> +            gen_vcpu="1"
> +        fi
> +
> +        if test -z $gen_vcpu

I would prefer to use quotes ("$gen_vcpu")


> +        then
> +            continue
> +        fi
> +
> +        dt_mknode "${path}" "vcpu$vcpu"
> +        dt_set "${path}/vcpu$vcpu" "compatible" "str_a" "xen,vcpu"
> +        dt_set "${path}/vcpu$vcpu" "id" "int"  "$vcpu"
> +
> +        if test -n $hard_affinity

also here. I'll fix it on commit


> +        then
> +            dt_set "${path}/vcpu$vcpu" "hard-affinity" "str" "$hard_affinity"
> +        fi
> +    done
> +}
> -- 
> 2.34.1
>