Re: [PATCH for-4.20 2/3] x86/PCI: init segments earlier

[Jason Andryuk <jason.andryuk@amd.com>]

On 2025-01-30 06:12, Jan Beulich wrote:
> In order for amd_iommu_detect_one_acpi()'s call to pci_ro_device() to
> have permanent effect, pci_segments_init() needs to be called ahead of
> making it there. Without this we're losing segment 0's r/o map, and thus
> we're losing write-protection of the PCI devices representing IOMMUs.
> Which in turn means that half-way recent Linux Dom0 will, as it boots,
> turn off MSI on these devices, thus preventing any IOMMU events (faults
> in particular) from being reported on pre-x2APIC hardware.
> 
> As the acpi_iommu_init() invocation was moved ahead of
> acpi_mmcfg_init()'s by the offending commit, move the call to
> pci_segments_init() accordingly.
> 
> Fixes: 3950f2485bbc ("x86/x2APIC: defer probe until after IOMMU ACPI table parsing")
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Tested-by: Jason Andryuk <jason.andryuk@amd.com>

Thanks,
Jason