[PATCH] PCI: Do not attempt to set ExtTag for VFs

From: Håkon Bugge

Date: Tue Nov 11 2025 - 08:24:47 EST


The bit for enabling extended tags is Reserved and Preserved (RsvdP)
for VFs. Hence, bail out early from pci_configure_extended_tags() if
the device is a VF.

Otherwise, we may see incorrect log messages such as:

kernel: pci 0000:af:00.2: enabling Extended Tags

(af:00.2 is a VF)

Fixes: 60db3a4d8cc9 ("PCI: Enable PCIe Extended Tags if supported")
Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
---
drivers/pci/probe.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 0ce98e18b5a87..014017e15bcc8 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2244,7 +2244,8 @@ int pci_configure_extended_tags(struct pci_dev *dev, void *ign)
u16 ctl;
int ret;

- if (!pci_is_pcie(dev))
+ /* PCI_EXP_DEVCTL_EXT_TAG is RsvdP in VFs */
+ if (!pci_is_pcie(dev) || dev->is_virtfn)
return 0;

ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
--
2.43.5