The patch titled
KVM breaks CPU hotplug
has been added to the -mm tree. Its filename is
kvm-breaks-cpu-hotplug.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: KVM breaks CPU hotplug
From: Shaohua Li <shaohua.li@xxxxxxxxx>
When testing CPU hotplug, I found cpu can't be onlined with kvm enabled
sometimes. The reason is smp_call_function_single is a nop if the thread
is running on the target cpu. I think CPU_ONLINE case doesn't require the
fix as the online CPU isn't plugged into sheduler yet.
Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
Cc: Avi Kivity <avi@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/kvm/kvm_main.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff -puN drivers/kvm/kvm_main.c~kvm-breaks-cpu-hotplug drivers/kvm/kvm_main.c
--- a/drivers/kvm/kvm_main.c~kvm-breaks-cpu-hotplug
+++ a/drivers/kvm/kvm_main.c
@@ -2782,6 +2782,7 @@ static int kvm_cpu_hotplug(struct notifi
void *v)
{
int cpu = (long)v;
+ int this_cpu;
switch (val) {
case CPU_DOWN_PREPARE:
@@ -2789,8 +2790,13 @@ static int kvm_cpu_hotplug(struct notifi
printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
cpu);
decache_vcpus_on_cpu(cpu);
- smp_call_function_single(cpu, kvm_arch_ops->hardware_disable,
- NULL, 0, 1);
+ this_cpu = get_cpu();
+ if (this_cpu == cpu)
+ kvm_arch_ops->hardware_disable(NULL);
+ else
+ smp_call_function_single(cpu,
+ kvm_arch_ops->hardware_disable, NULL, 0, 1);
+ put_cpu();
break;
case CPU_ONLINE:
printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
_
Patches currently in -mm which might be from shaohua.li@xxxxxxxxx are
git-acpi.patch
kvm-breaks-cpu-hotplug.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
