On 8/6/26 15:19, Tomasz Lichwala wrote:
On 6.08.2026 15:04, Przemek Kitszel wrote:
On 8/6/26 12:46, Tomasz Lichwala wrote:
When an E610 VF is running under Hyper-V, the VFLINKS register does not
carry valid link speed. The existing code reads speed from VFLINKS, which
does not reflect the actual negotiated speed. This results in ethtool
reporting a stale or incorrect link speed.
The Hyper-V synthetic NIC exposes the actual link status through
emulated PCI config space at offset 0x209 in VFLINKS register format.
Read and decode link status from there when checking link on E610 VFs.
Fixes: 4c44b450c69b ("ixgbevf: Add support for Intel(R) E610 device")
Reviewed-by: Marcin Szycik <[email protected]>
Signed-off-by: Tomasz Lichwala <[email protected]>
---
next time please provide changelog section here
Noted, will include changelog in subsequent versions.
drivers/net/ethernet/intel/ixgbevf/vf.c | 77 +++++++++++++++++++++----
1 file changed, 65 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/intel/ixgbevf/vf.c
b/drivers/net/ethernet/intel/ixgbevf/vf.c
index f6df86d124b9..8ad06e28b5de 100644
--- a/drivers/net/ethernet/intel/ixgbevf/vf.c
+++ b/drivers/net/ethernet/intel/ixgbevf/vf.c
@@ -1,14 +1,17 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 1999 - 2024 Intel Corporation. */
+#include <linux/unaligned.h>
+
#include "vf.h"
#include "ixgbevf.h"
[..]
+static s32 ixgbevf_hv_read_links_e610(struct ixgbe_hw *hw, u32 *links_reg)
+{
+ struct ixgbevf_adapter *adapter = hw->back;
+ u8 data[IXGBE_HV_LINK_STATUS_SIZE];
following Paul's suggestion, you could add:
if (IS_ENABLED(CONFIG_PCI_MMCONFIG)) {
dev_err_once(&adapter->pdev->dev, "cannot read link status, PCI_MMCONFIG is
required for Hyper-V\n");
return -EOPNOTSUPP;
}
and this will give user more information
IS_ENABLED() is really nice macro :)
I think you meant !IS_ENABLED() here.
oh yea
Without MMCONFIG, pci_read_config_byte() at offset 0x209 (extended
config space) will return a PCIBIOS error anyway, and the caller handles
that gracefully by reporting link down. I could add the explicit
IS_ENABLED check for a friendlier diagnostic message, but the behavior
is correct either way. Let me know if you'd prefer I add it in a v4.
yes, please do v4
+
+ for (int i = 0; i < IXGBE_HV_LINK_STATUS_SIZE; i++) {
+ int ret = pci_read_config_byte(adapter->pdev,
+ IXGBE_HV_LINK_STATUS_OFFSET + i,
+ &data[i]);
+ if (ret)
+ return pcibios_err_to_errno(ret);
+ }
+
+ *links_reg = get_unaligned_le32(data);
+ return 0;
+}
+
Thanks,
Tomasz
