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
