KVM: x86: use dynamic percpu allocations for shared msrs area
Use dynamic percpu allocations for the shared msrs structure,
to avoid using the limited reserved percpu space.
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 76f5446..c243b81 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -120,7 +120,7 @@
};
static struct kvm_shared_msrs_global __read_mostly shared_msrs_global;
-static DEFINE_PER_CPU(struct kvm_shared_msrs, shared_msrs);
+static struct kvm_shared_msrs __percpu *shared_msrs;
struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "pf_fixed", VCPU_STAT(pf_fixed) },
@@ -191,10 +191,10 @@
static void shared_msr_update(unsigned slot, u32 msr)
{
- struct kvm_shared_msrs *smsr;
u64 value;
+ unsigned int cpu = smp_processor_id();
+ struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
- 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) {
@@ -226,7 +226,8 @@
void kvm_set_shared_msr(unsigned slot, u64 value, u64 mask)
{
- struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs);
+ unsigned int cpu = smp_processor_id();
+ struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
if (((value ^ smsr->values[slot].curr) & mask) == 0)
return;
@@ -242,7 +243,8 @@
static void drop_user_return_notifiers(void *ignore)
{
- struct kvm_shared_msrs *smsr = &__get_cpu_var(shared_msrs);
+ unsigned int cpu = smp_processor_id();
+ struct kvm_shared_msrs *smsr = per_cpu_ptr(shared_msrs, cpu);
if (smsr->registered)
kvm_on_user_return(&smsr->urn);
@@ -5233,9 +5235,16 @@
goto out;
}
+ r = -ENOMEM;
+ shared_msrs = alloc_percpu(struct kvm_shared_msrs);
+ if (!shared_msrs) {
+ printk(KERN_ERR "kvm: failed to allocate percpu kvm_shared_msrs\n");
+ goto out;
+ }
+
r = kvm_mmu_module_init();
if (r)
- goto out;
+ goto out_free_percpu;
kvm_set_mmio_spte_mask();
kvm_init_msr_list();
@@ -5258,6 +5267,8 @@
return 0;
+out_free_percpu:
+ free_percpu(shared_msrs);
out:
return r;
}
@@ -5275,6 +5286,7 @@
#endif
kvm_x86_ops = NULL;
kvm_mmu_module_exit();
+ free_percpu(shared_msrs);
}
int kvm_emulate_halt(struct kvm_vcpu *vcpu)