On Sun, Oct 17, 2021 at 05:03:28PM +0300, Yishai Hadas wrote:

On 10/15/2021 11:59 PM, Alex Williamson wrote:

quoted

On Fri, 15 Oct 2021 17:16:54 -0300
Jason Gunthorpe [off-list ref] wrote:

quoted

On Fri, Oct 15, 2021 at 02:12:01PM -0600, Alex Williamson wrote:

quoted

On Fri, 15 Oct 2021 16:59:37 -0300
Jason Gunthorpe [off-list ref] wrote:

quoted

On Fri, Oct 15, 2021 at 01:48:20PM -0600, Alex Williamson wrote:

quoted

quoted

+static int mlx5vf_pci_set_device_state(struct mlx5vf_pci_core_device *mvdev,
+				       u32 state)
+{
+	struct mlx5vf_pci_migration_info *vmig = &mvdev->vmig;
+	u32 old_state = vmig->vfio_dev_state;
+	int ret = 0;
+
+	if (vfio_is_state_invalid(state) || vfio_is_state_invalid(old_state))
+		return -EINVAL;

if (!VFIO_DEVICE_STATE_VALID(old_state) || !VFIO_DEVICE_STATE_VALID(state))

AFAICT this macro doesn't do what is needed, eg

VFIO_DEVICE_STATE_VALID(0xF000) == true

What Yishai implemented is at least functionally correct - states this
driver does not support are rejected.

if (!VFIO_DEVICE_STATE_VALID(old_state) || !VFIO_DEVICE_STATE_VALID(state)) || (state & ~VFIO_DEVICE_STATE_MASK))

old_state is controlled by the driver and can never have random bits
set, user state should be sanitized to prevent setting undefined bits.

In that instance let's just write

old_state != VFIO_DEVICE_STATE_ERROR

?

Not quite, the user can't set either of the other invalid states
either.

OK so let's go with below as you suggested.
if (!VFIO_DEVICE_STATE_VALID(old_state) ||
     !VFIO_DEVICE_STATE_VALID(state) ||
      (state & ~VFIO_DEVICE_STATE_MASK))
           return -EINVAL;

This is my preference:

if (vmig->vfio_dev_state != VFIO_DEVICE_STATE_ERROR ||
    !vfio_device_state_valid(state) ||
    (state & !MLX5VF_SUPPORTED_DEVICE_STATES))

Do not put static variables in header files

Jason