KVM: arm64: Fail the idreg iterator if idregs aren't initialized

Return an error to userspace if the VM's ID register values haven't been
initialized in preparation for changing the debugfs file initialization
order.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240227094115.1723330-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index e3faedc8b7a30d9d711e0355a5158fb2db257294..e9319d90d66ffb7be0a87b03cae2aff075ac0f08 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -3431,7 +3431,8 @@ static void *idregs_debug_start(struct seq_file *s, loff_t *pos)
        mutex_lock(&kvm->arch.config_lock);
 
        iter = &kvm->arch.idreg_debugfs_iter;
-       if (*iter == (u8)~0) {
+       if (test_bit(KVM_ARCH_FLAG_ID_REGS_INITIALIZED, &kvm->arch.flags) &&
+           *iter == (u8)~0) {
                *iter = *pos;
                if (*iter >= KVM_ARM_ID_REG_NUM)
                        iter = NULL;