[PATCH v5 29/30] RFC: KVM: x86: Remove cpus_hardware_enabled and related sanity check

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

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

Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 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 1f791c93391b..7505dd4ae695 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11958,23 +11958,16 @@ void kvm_arch_resume(int usage_count)
 	}
 }
 
-static cpumask_t cpus_hardware_enabled = CPU_MASK_NONE;
-
 static int __hardware_enable(void)
 {
-	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 %pSb\n",
-			cpu, __builtin_return_address(0));
-	else
-		cpumask_set_cpu(cpu, &cpus_hardware_enabled);
+			smp_processor_id(), __builtin_return_address(0));
 	return r;
 }
 
@@ -11988,13 +11981,7 @@ 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