Re: [PATCH v6] PCI: vmd: Add feature to scan BIOS enumerated devices.

[Nirmal Patel <nirmal.patel@linux.intel.com>]

On Tue, 23 Jun 2026 01:20:58 +0000
sashiko-bot@kernel.org wrote:

> Thank you for your contribution! Sashiko AI review found 1 potential
> issue(s) to consider:
> - [Medium] The IRQ domain and its associated fwnode are permanently
> leaked for devices with VMD_FEAT_USE_BIOS_INFO due to an
> unconditional early return in vmd_remove_irq_domain(). --
> 
> commit 0711c95d550249c54951b1f20ee8a7fe26dafc0b
> Author: Nirmal Patel <nirmal.patel@linux.intel.com>
> 
> PCI: vmd: Add feature to scan BIOS enumerated devices.
> 
> This commit adds support for newer VMD hardware (like device ID
> 0x28c1) by using BIOS-configured shadow registers and bus ranges
> instead of manually configuring them.
> 
> > diff --git a/drivers/pci/controller/vmd.c
> > b/drivers/pci/controller/vmd.c --- a/drivers/pci/controller/vmd.c
> > +++ b/drivers/pci/controller/vmd.c
> > @@ -374,6 +393,9 @@ static void vmd_set_msi_remapping(struct
> > vmd_dev *vmd, bool enable) 
> >  static void vmd_remove_irq_domain(struct vmd_dev *vmd)
> >  {
> > +	if (!!(vmd->features & VMD_FEAT_USE_BIOS_INFO))
> > +		return;
> > +  
> 
> [Severity: Medium]
> Does this early return cause an IRQ domain and fwnode resource leak?
> 
> When a VMD device like 0x28c1 (which has VMD_FEAT_USE_BIOS_INFO) is
> probed, vmd_enable_domain() can conditionally create an IRQ domain if
> running under Xen or if the BIOS-configured shadow registers
> offset[0] or offset[1] are non-zero.
> 
> If the driver is unloaded or fails later in the probe process, this
> return causes the function to exit immediately before calling
> irq_domain_remove() and irq_domain_free_fwnode(). Should the IRQ
> domain teardown still execute even if VMD_FEAT_USE_BIOS_INFO is set?
> 
Fair point. xen can cause irq domain deletion failure. Let me remove
the return statement from vmd_remove_irq_domain.