On 6/13/19 10:18 AM, Cornelia Huck wrote:
On Tue, 11 Jun 2019 10:19:29 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
On 6/7/19 4:03 PM, Alex Williamson wrote:
On Fri, 7 Jun 2019 14:26:13 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
On 6/6/19 12:15 PM, Alex Williamson wrote:
On Thu, 6 Jun 2019 09:32:24 -0600
Alex Williamson <alex.williamson@xxxxxxxxxx> wrote:
On Thu, 6 Jun 2019 16:44:17 +0200
Cornelia Huck <cohuck@xxxxxxxxxx> wrote:
Add a rough implementation for vfio-ap.
Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx>
---
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
One thing that this does is limiting us to things that can be expressed
with "if you encounter key=value, take value (possibly decomposed) and
write it to <device>/key". A problem with this generic approach is that
the code cannot decide itself whether value should be decomposed (and
if yes, with which delimiter), or not. We also cannot cover any
configuration that does not fit this pattern; so I think we need both
generic (for flexibility, and easy extensibility), and explicitly
defined options to cover more complex cases.
[As an aside, how should we deal with duplicate key= entries? Not
allowed, last one wins, or all are written to the sysfs attribute?]
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.
How would we know what attributes are vendor defined? The above `find`
strips out the power, uevent, and remove attributes, which for GVT-g
leaves only the vendor defined attributes[1], but I don't know how to
instead do a positive match of the vendor attributes without
unmaintainable lookup tables. This starts to get into the question of
how much do we want to (or need to) protect the user from themselves.
If we let the user specify a key=value of remove=1 and the device
immediately disappears, is that a bug or a feature? Thanks,
Alex
By vendor defined, I meant attributes that are not defined by the mdev
framework, such as the 'remove' attribute.
And those defined by the base driver core like uevent, I guess.
Yes
As far as whether allowing
specification of remove-1, I'd have to play with that and see what all
of the ramifications are.
It does feel a bit odd to me (why would you configure it if you
immediately want to remove it again?)
This was in response to Alex's comment. My personal preference is to
exclude attributes that are not vendor created, at least to the
extent it is possible to determine such.
Tony K
[1] GVT-g doesn't actually have an writable attributes, so we'd also
minimally want to add a test to skip read-only attributes.
Probably a good idea.
Agreed.
