diff options
authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2019-04-24 09:34:46 +0200
committerPaul E. McKenney <paulmck@linux.ibm.com>2019-05-28 09:06:09 -0700
commita6fda6dab93c2c06ef4b8cb4b9258df6674d2438 (patch)
parentc682db558e6eec10a711b0a6bcb8c35fd15f6a39 (diff)
rcutorture: Tweak kvm options
In one of my rcutorture tests the TSC clocksource got marked unstable due to a large difference in the TSC value. I'm not sure if the guest run for a long time with disabled interrupts or if the host was very busy and didn't schedule the guest for some time. I took a look on the qemu/KVM options and decided to update the options: - Use kvm{32|64} as CPU. We could probably use `host' (like ARM does) for maximum available features but since we don't run any userland I'm not sure if it makes any difference. - Drop the "noapic" option. There is no history why the APIC was disabled, I see no reason for it. Once old qemu versions fade away, we can add "x2apic=on,tsc-deadline=on,hypervisor=on,tsc_adjust=on". - Additional config options. It ensures that the kernel knowns that it runs as a kvm guest and can use virt devices like the kvm-clock as clocksource. The kvm-clock was the main motivation here. - I didn't add a random HW device. It would make the random device ready earlier (not it doesn't complete the initialisation at all) but I doubt that there is any need for this. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> [ paulmck: The world is not quite ready for CONFIG_PARAVIRT_SPINLOCKS=y and x2apic, so they are omitted for the time being. ] Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2 files changed, 15 insertions, 1 deletions
diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh
index 6bcb8b5b2ff2..c3a49fb4d6f6 100644
--- a/tools/testing/selftests/rcutorture/bin/functions.sh
+++ b/tools/testing/selftests/rcutorture/bin/functions.sh
@@ -172,7 +172,7 @@ identify_qemu_append () {
local console=ttyS0
case "$1" in
- echo noapic selinux=0 initcall_debug debug
+ echo selinux=0 initcall_debug debug
@@ -191,8 +191,19 @@ identify_qemu_append () {
# Output arguments for qemu arguments based on the TORTURE_QEMU_MAC
# and TORTURE_QEMU_INTERACTIVE environment variables.
identify_qemu_args () {
+ local KVM_CPU=""
+ case "$1" in
+ qemu-system-x86_64)
+ KVM_CPU=kvm64
+ ;;
+ qemu-system-i386)
+ KVM_CPU=kvm32
+ ;;
+ esac
case "$1" in
+ echo -machine q35,accel=kvm
+ echo -cpu ${KVM_CPU}
echo -machine virt,gic-version=host -cpu host
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
index d2d2a86139db..e19a444a0684 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
+++ b/tools/testing/selftests/rcutorture/configs/rcu/CFcommon
@@ -1,2 +1,5 @@