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Commit 013f6a5d authored by Marcelo Tosatti's avatar Marcelo Tosatti
Browse files

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: default avatarGleb Natapov <gleb@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent d686a547

arch/x86/kvm/x86.c

+18 −6
Original line number Diff line number Diff line
@@ -120,7 +120,7 @@ struct kvm_shared_msrs { 
};



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 kvm_on_user_return(struct user_return_notifier *urn) 


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 @@ static void kvm_shared_msr_cpu_online(void) 


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 @@ EXPORT_SYMBOL_GPL(kvm_set_shared_msr); 


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 @@ int kvm_arch_init(void *opaque) 
		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 @@ int kvm_arch_init(void *opaque) 


	return 0;



out_free_percpu:

	free_percpu(shared_msrs);

out:

	return r;

}
@@ -5275,6 +5286,7 @@ void kvm_arch_exit(void) 
#endif

	kvm_x86_ops = NULL;

	kvm_mmu_module_exit();

	free_percpu(shared_msrs);

}



int kvm_emulate_halt(struct kvm_vcpu *vcpu)