Re: [PATCH] virtio_pci: modify ENOENT to EINVAL

On Thu, Nov 10, 2022 at 11:31 AM Angus Chen [off-list ref] wrote:

Hi Jason.

quoted

-----Original Message-----
From: Jason Wang <redacted>
Sent: Wednesday, November 2, 2022 1:34 PM
To: Angus Chen <redacted>
Cc: mst@redhat.com; virtualization@lists.linux-foundation.org;
linux-kernel@vger.kernel.org; lingshan.zhu@intel.com
Subject: Re: [PATCH] virtio_pci: modify ENOENT to EINVAL

On Tue, Nov 1, 2022 at 7:17 PM Angus Chen [off-list ref]
wrote:

quoted

Virtio_crypto use max_data_queues+1 to setup vqs,
we use vp_modern_get_num_queues to protect the vq range in setup_vq.
We could enter index >= vp_modern_get_num_queues(mdev) in setup_vq
if common->num_queues is not set well,and it return -ENOENT.
It is better to use -EINVAL instead.

I'm not sure I get this. It would be better to describe:

1) what kind of issues can we see if we return -ENOENT
2) why -EINVAL can help in this case

Thanks

Thank you for your reply.
We use a robot to test our dpu to get the return value of probe.
 We often get ENOENT form ' setup_vq ' function because of device error.
Most of time, my device can't handle queue_enable well.
This time,we get 'ENOENT' because the device set max_data_queues bigger than num_queues.

Ok, I see, ENOENT is not very popular on linux but I'm not sure it's
worth bothering.

I think EINVAL is used when the value of some parameter is wrong.
Btw,it not a big deal,I can modify the robot to workaround.

Btw, the error code is not a part of the ABI, so depending on that is
kind of fragile.

Thanks

quoted

quoted

Signed-off-by: Angus Chen <redacted>
---
 drivers/virtio/virtio_pci_modern.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_pci_modern.c

b/drivers/virtio/virtio_pci_modern.c

quoted

index c3b9f2761849..edf2e18014cd 100644

--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c

@@ -303,7 +303,7 @@ static struct virtqueue *setup_vq(struct

virtio_pci_device *vp_dev,

quoted

        int err;

        if (index >= vp_modern_get_num_queues(mdev))
-               return ERR_PTR(-ENOENT);
+               return ERR_PTR(-EINVAL);

        /* Check if queue is either not available or already active. */
        num = vp_modern_get_queue_size(mdev, index);
--
2.25.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization