From 82b6aded6f5c2d68180d47cd53e042f732c9b83e Mon Sep 17 00:00:00 2001
From: Josh Lay <me@jlay.io>
Date: Thu, 24 Sep 2020 21:32:56 -0500
Subject: [PATCH] update comments and topology

---
 start-win10 | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/start-win10 b/start-win10
index 274e894..aa69043 100755
--- a/start-win10
+++ b/start-win10
@@ -12,7 +12,7 @@
 # - resets host isolation on VM shutdown
 #
 # define the CPUs (cores/threads) to isolate for the VM
-VM_CORES='0-11,24-35'
+VM_CORES='0-19,24-43'
 # Tip: refer to 'virsh capabilities | grep siblings'
 # this will show CPU topology information for the host
 # allows one to pick optimal layout for the VM
@@ -33,14 +33,12 @@ VM_CORES='0-11,24-35'
 #  - SMT enabled
 #
 # reduce kernel jitter
-sudo sysctl vm.stat_interval=120
-sudo sysctl kernel.watchdog=0
+sudo sh -c 'sysctl vm.stat_interval=120 ; sysctl kernel.watchdog=0'
 
 # attempt to reset shielding, we want to create it with current params
 # and remove any existing slices from previous VM boots
 # we want it to be created with current params, such as possibly-changed pinned CPUs
-sudo cset shield --reset --sysset=host.slice --userset=windows10.slice
-sudo cset set -d windows10.slice
+sudo sh -c 'cset shield --reset --sysset=host.slice --userset=windows10.slice ; cset set -d windows10.slice'
 
 # shield cores
 # userset slice must match the partition defined in libvirt xml, eg:
@@ -52,26 +50,30 @@ sudo cset set -d windows10.slice
 #  <os>
 sudo cset shield -c $VM_CORES --sysset=host.slice --userset=windows10.slice
 
-# setup looking glass
-#sudo touch /dev/shm/looking-glass
-#sudo chown jlay:kvm /dev/shm/looking-glass
-#sudo chmod 660 /dev/shm/looking-glass
-
 # start the VM
 virsh start windows10
 
-# set higher priority
-QEMU_PID=$(sudo ps fauxww | awk '$0 ~ /qemu.*windows1[0]/ {print $2}')
-sudo renice -20 -p ${QEMU_PID}
-sudo chrt -f -p 99 ${QEMU_PID}
+# determine QEMU vCPU PIDs
+QEMU_PIDS=$(sudo egrep 'vcpu.*pid' /var/run/libvirt/qemu/windows10.xml | cut -d\' -f4)
+
+# set higher priority for vCPU PIDs
+sudo renice -20 -p ${QEMU_PIDS}
+# either of these attempts at real time seem to freeze on boot
+# try a different kernel (not 5.8.11)
+#for CPUPID in ${QEMU_PIDS}; do 
+##	sudo chrt -f -p 99 ${CPUPID}
+#	sudo chrt -r -p 99 ${CPUPID}
+#done
 
 echo "Waiting for windows10 VM to stop before resetting cpusets"
 while true; do
 	# chill a bit
 	sleep 10
 	# get vm state, check if it's off
-	VM_STATE=$(sudo virsh dominfo windows10 | awk '$1 ~ /State/ {print $NF}')
-	if [ "$VM_STATE" == 'off' ]; then
+	if test -f "/var/run/libvirt/qemu/windows10.xml"; then
+		VM_STATE="on" # doesn't do much (yet?), just here to fill a spot
+	else
+		VM_STATE="off"
 		echo -e "windows10 VM shut down, setting cpusets back to normal\n"
 		sudo cset shield --reset --sysset=host.slice --userset=windows10.slice
 		exit 0