Re: [PATCH RFC 1/1] allow to specify additional config data

Tony Krowiak
2019-06-07T18:26:21Z

On 6/6/19 12:15 PM, Alex Williamson wrote:
> On Thu, 6 Jun 2019 09:32:24 -0600
> Alex Williamson <alex.williamson@redhat.com> wrote:
>
>> On Thu, 6 Jun 2019 16:44:17 +0200
>> Cornelia Huck <cohuck@redhat.com> wrote:
>>
>>> Add a rough implementation for vfio-ap.
>>>
>>> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
>>> ---
>>> mdevctl.libexec | 25 ++++++++++++++++++++++
>>> mdevctl.sbin | 56 ++++++++++++++++++++++++++++++++++++++++++++++++-
>>> 2 files changed, 80 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/mdevctl.libexec b/mdevctl.libexec
>>> index 804166b5086d..cc0546142924 100755
>>> --- a/mdevctl.libexec
>>> +++ b/mdevctl.libexec
>>> @@ -54,6 +54,19 @@ wait_for_supported_types () {
>>> fi
>>> }
>>>
>>> +# configure vfio-ap devices <config entry> <matrix attribute>
>>> +configure_ap_devices() {
>>> + list="`echo "${config[$1]}" | sed 's/,/ /'`"
>>> + [ -z "$list" ] && return
>>> + for a in $list; do
>>> + echo "$a" > "$supported_types/${config[mdev_type]}/devices/$uuid/$2"
>>> + if [ $? -ne 0 ]; then
>>> + echo "Error writing '$a' to '$uuid/$2'" >&2
>>> + exit 1
>>> + fi
>>> + done
>>> +}
>>> +
>>> case ${1} in
>>> start-mdev|stop-mdev)
>>> if [ $# -ne 2 ]; then
>>> @@ -148,6 +161,18 @@ case ${cmd} in
>>> echo "Error creating mdev type ${config[mdev_type]} on $parent" >&2
>>> exit 1
>>> fi
>>> +
>>> + # some types may specify additional config data
>>> + case ${config[mdev_type]} in
>>> + vfio_ap-passthrough)
>>
>> I think this could have some application beyond ap too, I know NVIDIA
>> GRID vGPUs do have some controls under the vendor hierarchy of the
>> device, ex. setting the frame rate limiter. The implementation here is
>> a bit rigid, we know a specific protocol for a specific mdev type, but
>> for supporting arbitrary vendor options we'd really just want to try to
>> apply whatever options are provided. If we didn't care about ordering,
>> we could just look for keys for every file in the device's immediate
>> sysfs hierarchy and apply any value we find, independent of the
>> mdev_type, ex. intel_vgpu/foo=bar Thanks,
>
> For example:
>
> for key in find -P $mdev_base/$uuid/ \( -path
> "$mdev_base/$uuid/power/*" -o -path $mdev_base/$uuid/uevent -o -path $mdev_base/$uuid/remove \) -prune -o -type f -print | sed -e "s|$mdev_base/$uuid/||g"); do
> [ -z ${config[$key]} ] && continue
> ... parse value(s) and iteratively apply to key
> done
>
> The find is a little ugly to exclude stuff, maybe we just let people do
> screwy stuff like specify remove=1 in their config. Also need to think
> about whether we're imposing a delimiter to apply multiple values to a
> key that conflicts with the attribute usage. Thanks,
>
> Alex

I like the idea of looking for files in the device's immediate sysfs
hierarchy, but maybe the find could exclude attributes that are
not vendor defined.

>
>>> + configure_ap_devices ap_adapters assign_adapter
>>> + configure_ap_devices ap_domains assign_domain
>>> + configure_ap_devices ap_control_domains assign_control_domain
>>> + # TODO: is assigning idempotent? Should we unwind on error?
>>> + ;;
>>> + *)
>>> + ;;
>>> + esac
>>> ;;
>>>
>>> add-mdev)
>>> diff --git a/mdevctl.sbin b/mdevctl.sbin
>>> index 276cf6ddc817..eb5ee0091879 100755
>>> --- a/mdevctl.sbin
>>> +++ b/mdevctl.sbin
>>> @@ -33,6 +33,8 @@ usage() {
>>> echo "set-start <mdev UUID>: change mdev start policy, if no option specified," >&2
>>> echo " system default policy is used" >&2
>>> echo " options: [--auto] [--manual]" >&2
>>> + echo "set-additional-config <mdev UUID> {fmt...}: supply additional configuration" >&2
>>> + echo "show-additional-config-format <mdev UUiD>: prints the format expected by the device" >&2
>>> echo "list-all: list all possible mdev types supported in the system" >&2
>>> echo "list-available: list all mdev types currently available" >&2
>>> echo "list-mdevs: list currently configured mdevs" >&2
>>> @@ -48,7 +50,7 @@ while (($# > 0)); do
>>> --manual)
>>> config[start]=manual
>>> ;;
>>> - start-mdev|stop-mdev|remove-mdev|set-start)
>>> + start-mdev|stop-mdev|remove-mdev|set-start|show-additional-config-format)
>>> [ $# -ne 2 ] && usage
>>> cmd=$1
>>> uuid=$2
>>> @@ -67,6 +69,14 @@ while (($# > 0)); do
>>> cmd=$1
>>> break
>>> ;;
>>> + set-additional-config)
>>> + [ $# -le 2 ] && usage
>>> + cmd=$1
>>> + uuid=$2
>>> + shift 2
>>> + addtl_config="$*"
>>> + break
>>> + ;;
>>> *)
>>> usage
>>> ;;
>>> @@ -114,6 +124,50 @@ case ${cmd} in
>>> fi
>>> ;;
>>>
>>> + set-additional-config)
>>> + file=$(find $persist_base -name $uuid -type f)
>>> + if [ -w "$file" ]; then
>>> + read_config "$file"
>>> + if [ ${config[start]} == "auto" ]; then
>>> + systemctl stop mdev@$uuid.service
>>> + fi
>>> + # FIXME: validate input!
>>> + for i in $addtl_config; do
>>> + key="`echo "$i" | cut -d '=' -f 1`"
>>> + value="`echo "$i" | cut -d '=' -f 2-`"
>>> + if grep -q ^$key $file; then
>>> + if [ -z "$value" ]; then
>>> + sed -i "s/^$key=.*//g" $file
>>> + else
>>> + sed -i "s/^$key=.*/$key=$value/g" $file
>>> + fi
>>> + else
>>> + echo "$i" >> "$file"
>>> + fi
>>> + done
>>> + if [ ${config[start]} == "auto" ]; then
>>> + systemctl start mdev@$uuid.service
>>> + fi
>>> + else
>>> + exit 1
>>> + fi
>>> + ;;
>>> +
>>> + show-additional-config-format)
>>> + file=$(find $persist_base -name $uuid -type f)
>>> + read_config "$file"
>>> + case ${config[mdev_type]} in
>>> + vfio_ap-passthrough)
>>> + echo "ap_adapters=<comma-separated list of adapters>"
>>> + echo "ap_domains=<comma-separated list of domains>"
>>> + echo "ap_control_domains=<comma-separated list of control domains>"
>>> + ;;
>>> + *)
>>> + echo "no additional configuration defined"
>>> + ;;
>>> + esac
>>> + ;;
>>> +
>>> list-mdevs)
>>> for mdev in $(find $mdev_base/ -maxdepth 1 -mindepth 1 -type l); do
>>> uuid=$(basename $mdev)
>>
>