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: