[PATCH v3 21/22] RFC: KVM: x86: Remove cpus_hardware_enabled and related sanity check

[isaku.yamahata@intel.com]

From: Isaku Yamahata <isaku.yamahata@intel.com>

cpus_hardware_enabled mask seems incomplete protection against other kernel
component using CPU virtualization feature.  Because it's obscure and
incomplete, remove the check.

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
---
 arch/x86/kvm/x86.c | 15 +--------------
 1 file changed, 1 insertion(+), 14 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f0382f3d5baf..15e123757b11 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11834,23 +11834,16 @@ void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
 }
 EXPORT_SYMBOL_GPL(kvm_vcpu_deliver_sipi_vector);
 
-static cpumask_t cpus_hardware_enabled = CPU_MASK_NONE;
-
 static int __hardware_enable(void *caller_name)
 {
-	int cpu = raw_smp_processor_id();
 	int r;
 
 	WARN_ON_ONCE(preemptible());
 
-	if (cpumask_test_cpu(cpu, &cpus_hardware_enabled))
-		return 0;
 	r = static_call(kvm_x86_hardware_enable)();
 	if (r)
 		pr_warn("kvm: enabling virtualization on CPU%d failed during %s()\n",
-			cpu, (const char *)caller_name);
-	else
-		cpumask_set_cpu(cpu, &cpus_hardware_enabled);
+			smp_processor_id(), (const char *)caller_name);
 	return r;
 }
 
@@ -11864,13 +11857,7 @@ static void hardware_enable(void *arg)
 
 static void hardware_disable(void *junk)
 {
-	int cpu = raw_smp_processor_id();
-
 	WARN_ON_ONCE(preemptible());
-
-	if (!cpumask_test_cpu(cpu, &cpus_hardware_enabled))
-		return;
-	cpumask_clear_cpu(cpu, &cpus_hardware_enabled);
 	static_call(kvm_x86_hardware_disable)();
 	drop_user_return_notifiers();
 }
-- 
2.25.1