On 12/17/2009 05:01 PM, Sheng Yang wrote:
-void kvm_define_shared_msr(unsigned slot, u32 msr)
+static void shared_msr_update(unsigned slot, u32 msr)
{
- int cpu;
+ struct kvm_shared_msrs *smsr;
u64 value;
+ smsr =&__get_cpu_var(shared_msrs);
+ /* only read, and nobody should modify it at this time,
+ * so don't need lock */
+ if (slot>= shared_msrs_global.nr) {
+ printk(KERN_ERR "kvm: invalid MSR slot!");
+ return;
+ }
+ if (smsr->values[slot].initialized)
+ return;
I don't think .initialized is worthwhile. shared_msr_update is run very
rarely.
The reason is, after cpu hotplug, the MSR_TSC_AUX would be rewritten by
vsyscall_init again. But in the hotplug notifier chain, KVM has higher
priority(20 vs 0 for vsyscall_init), so maybe the rdmsr() here would get a
bogus value... Then I think prevent it from initializing again should be
safer.
So let's raise vsyscall_init's priority?
But I just think of another issue: if we hot plug in a cpu(without hot plug
off), it would have a bogus value as well in the same path? Sound
troublesome...
Removing .initialized would take care of this issue.
--
error compiling committee.c: too many arguments to function
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