(2010/11/18 11:33), Zachary Amsden wrote:
On 11/17/2010 04:04 PM, Takuya Yoshikawa wrote:
(2010/11/18 10:59), Zachary Amsden wrote:
On 11/15/2010 10:35 PM, Takuya Yoshikawa wrote:
In kvm_cpu_hotplug(), only CPU_STARTING case is protected by kvm_lock.
This patch adds missing protection for CPU_DYING case.
Signed-off-by: Takuya Yoshikawa<yoshikawa.takuya@xxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 339dd43..0fdd911 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2148,7 +2148,9 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
case CPU_DYING:
printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
cpu);
+ spin_lock(&kvm_lock);
hardware_disable(NULL);
+ spin_unlock(&kvm_lock);
break;
case CPU_STARTING:
printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",
I believe this is correct.
You mean lock is not necessary?
No, I believe your patch is correct and the lock should be there. Did you test with spinlock debugging just to be sure?
Sorry but no.
I have no experience with cpu hotplug.
So I thought it would take too much time to do real test by myself and reported like this this time.
Any easy way to test?
Takuya
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