* [PATCH] PCI: Do not attempt to set ExtTag for VFs
@ 2025-11-11 13:24 Håkon Bugge
2025-11-11 13:30 ` Ilpo Järvinen
0 siblings, 1 reply; 2+ messages in thread
From: Håkon Bugge @ 2025-11-11 13:24 UTC (permalink / raw)
To: Bjorn Helgaas, Sinan Kaya; +Cc: Håkon Bugge, linux-pci, linux-kernel
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@oracle.com>
---
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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] PCI: Do not attempt to set ExtTag for VFs
2025-11-11 13:24 [PATCH] PCI: Do not attempt to set ExtTag for VFs Håkon Bugge
@ 2025-11-11 13:30 ` Ilpo Järvinen
0 siblings, 0 replies; 2+ messages in thread
From: Ilpo Järvinen @ 2025-11-11 13:30 UTC (permalink / raw)
To: Håkon Bugge; +Cc: Bjorn Helgaas, Sinan Kaya, linux-pci, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 1135 bytes --]
On Tue, 11 Nov 2025, Håkon Bugge wrote:
> The bit for enabling extended tags is Reserved and Preserved (RsvdP)
> for VFs.
Please add a PCIe spec reference.
> 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@oracle.com>
> ---
> 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);
>
--
i.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-11-11 13:24 [PATCH] PCI: Do not attempt to set ExtTag for VFs Håkon Bugge
2025-11-11 13:30 ` Ilpo Järvinen
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