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

Alex Williamson
2019-06-06T16:16:07Z

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

> > + 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)
>