Re: [PATCH net-next v4 14/15] ixd: add the core initialization

[Larysa Zaremba <larysa.zaremba@intel.com>]

Sashiko expressed concerns with virtchnl version handling in ixd. I think it is 
fine as-is, but here is how it can be addressed:

commit 736215457094a287aa8f40af322e0bc7ab94dddc
Author: Larysa Zaremba <larysa.zaremba@intel.com>
Date:   Mon Jul 13 15:44:55 2026 +0200

    fixup! ixd: add the core initialization

diff --git a/drivers/net/ethernet/intel/ixd/ixd_virtchnl.c b/drivers/net/ethernet/intel/ixd/ixd_virtchnl.c
index 66049d1b1d15..5b04769443b9 100644
--- a/drivers/net/ethernet/intel/ixd/ixd_virtchnl.c
+++ b/drivers/net/ethernet/intel/ixd/ixd_virtchnl.c
@@ -120,8 +120,11 @@ static int ixd_handle_vc_ver(struct ixd_adapter *adapter, void *recv_buff,
                return -EBADMSG;

        recv_ver = recv_buff;
-       if (le32_to_cpu(need_ver.major) > le32_to_cpu(recv_ver->major))
+       if (le32_to_cpu(need_ver.major) != le32_to_cpu(recv_ver->major))
                return -EOPNOTSUPP;
+       if (le32_to_cpu(recv_ver->minor) != le32_to_cpu(need_ver.minor))
+               dev_warn(ixd_to_dev(adapter),
+                        "Virtchnl minor version does not match, proceed with caution\n");

        adapter->vc_ver.major = le32_to_cpu(recv_ver->major);
        adapter->vc_ver.minor = le32_to_cpu(recv_ver->minor);

Everything else:

[...]

> > +	libie_ctlq_xn_shutdown(adapter->xnm);
> > +	ixd_trigger_reset(adapter);
> > +	ixd_deinit_dflt_mbx(adapter);
> Could this sequence trigger a race condition causing PCIe AER fatal errors?
> The hardware reset is triggered here before the mailbox polling task
> (mbx_task) is canceled inside ixd_deinit_dflt_mbx().
> If mbx_task runs concurrently with or immediately after the reset trigger,
> it might access MMIO doorbell registers while the device is actively in a
> global reset.
> 
Not an issue with available HW

[...]

> >  	ixd_trigger_reset(adapter);
> >  	ixd_deinit_dflt_mbx(adapter);
> Similarly to ixd_init_task(), does triggering the reset before
> ixd_deinit_dflt_mbx() here risk the mbx_task touching MMIO during reset?
> Perhaps the newly added polling task should be canceled before the hardware
> reset is triggered?
> 
This is not an issue with available HW, and consistent with existing idpf flow.

[...]

> > +static int ixd_req_vc_caps(struct ixd_adapter *adapter)
> > +{
> > +	const struct ixd_ctlq_req req = {
> > +		.opcode = VIRTCHNL2_OP_GET_CAPS,
> > +		.send_size = sizeof(struct virtchnl2_get_capabilities),
> > +		.ctx = NULL,
> > +		.send_buff_init = NULL,
> > +		.recv_process = ixd_handle_caps,
> > +	};
> > +
> > +	return ixd_ctlq_do_req(adapter, &req);
> > +}
> Because send_buff_init is NULL, will the driver send an all-zero request
> payload for capabilities and resources?
> Requesting 0 max vectors and 0 RX queues might cause the Control Plane to
> respond with only the default mailbox vector, starving the driver of
> interrupts for its networking queues.
> 
We do not currently have any queues

[...]