[PATCH 2/2] KVM: SVM: drop useless cpumask_test_cpu() in pre_sev_run()

[Yury Norov]

Testing cpumask for a CPU to be cleared just before setting the exact
same CPU is useless because the end result is always the same: CPU is
set.

While there, switch CPU setter to a non-atomic version. Atomicity is
useless here because sev_writeback_caches() ends up with a plain
for_each_cpu() loop in smp_call_function_many_cond(), which is not
atomic by nature.

Fixes: 6f38f8c57464 ("KVM: SVM: Flush cache only on CPUs running SEV guest")
Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
 arch/x86/kvm/svm/sev.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 49d7557de8bc..8170674d39c1 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3498,8 +3498,7 @@ int pre_sev_run(struct vcpu_svm *svm, int cpu)
 	 * have encrypted, dirty data in the cache, and flush caches only for
 	 * CPUs that have entered the guest.
 	 */
-	if (!cpumask_test_cpu(cpu, to_kvm_sev_info(kvm)->have_run_cpus))
-		cpumask_set_cpu(cpu, to_kvm_sev_info(kvm)->have_run_cpus);
+	__cpumask_set_cpu(cpu, to_kvm_sev_info(kvm)->have_run_cpus);
 
 	/* Assign the asid allocated with this SEV guest */
 	svm->asid = asid;
-- 
2.43.0