[PATCH v2 3/3] KVM: arm64: Drop redundant READ_ONCE() in pkvm_hyp_vm_is_created()

[Fuad Tabba]

is_created is written under config_lock. Every concurrent reader is
serialised against that write: pkvm_create_hyp_vm() under config_lock,
and the memslot path (kvm_arch_prepare_memory_region) via slots_lock,
which the creation writer also holds. The teardown-path accesses have no
concurrent writer. The read is therefore serialised, and the READ_ONCE()
is unnecessary.

Reviewed-by: Keir Fraser <keirf at google.com>
Signed-off-by: Fuad Tabba <fuad.tabba at linux.dev>
---
 arch/arm64/kvm/pkvm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c
index 67b90a58fbea2..008766273912e 100644
--- a/arch/arm64/kvm/pkvm.c
+++ b/arch/arm64/kvm/pkvm.c
@@ -185,7 +185,11 @@ static int __pkvm_create_hyp_vm(struct kvm *kvm)
 
 bool pkvm_hyp_vm_is_created(struct kvm *kvm)
 {
-	return READ_ONCE(kvm->arch.pkvm.is_created);
+	/*
+	 * Serialised by config_lock/slots_lock, or by VM lifecycle at
+	 * teardown, so a plain read suffices.
+	 */
+	return kvm->arch.pkvm.is_created;
 }
 
 int pkvm_create_hyp_vm(struct kvm *kvm)
-- 
2.39.5