Property num_cpu and feature is read-only once eiointc is created, which
is set with KVM_DEV_LOONGARCH_EXTIOI_GRP_CTRL attr group before device
creation.
Attr group KVM_DEV_LOONGARCH_EXTIOI_GRP_SW_STATUS is to update register
and software state for migration and reset usage, property num_cpu and
feature can not be update again if it is created already.
Here discard write operation with property num_cpu and feature in attr
group KVM_DEV_LOONGARCH_EXTIOI_GRP_CTRL.
Cc: stable@vger.kernel.org
Fixes: 1ad7efa552fd ("LoongArch: KVM: Add EIOINTC user mode read and write functions")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
arch/loongarch/kvm/intc/eiointc.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
index 0b648c56b0c3..b48511f903b5 100644
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -910,9 +910,22 @@ static int kvm_eiointc_sw_status_access(struct kvm_device *dev,
data = (void __user *)attr->addr;
switch (addr) {
case KVM_DEV_LOONGARCH_EXTIOI_SW_STATUS_NUM_CPU:
+ /*
+ * Property num_cpu and feature is read-only once eiointc is
+ * created with KVM_DEV_LOONGARCH_EXTIOI_GRP_CTRL group API
+ *
+ * Disable writing with KVM_DEV_LOONGARCH_EXTIOI_GRP_SW_STATUS
+ * group API
+ */
+ if (is_write)
+ return ret;
+
p = &s->num_cpu;
break;
case KVM_DEV_LOONGARCH_EXTIOI_SW_STATUS_FEATURE:
+ if (is_write)
+ return ret;
+
p = &s->features;
break;
case KVM_DEV_LOONGARCH_EXTIOI_SW_STATUS_STATE:
--
2.39.3