From: Kuppuswamy Sathyanarayanan <[email protected]>
If PF does not implement ATS and VF implements/uses it, it might lead to runtime issues. Also, as per spec r4.0, sec 9.3.7.8, PF should implement ATS if VF implements it. So add additional check to confirm given device aligns with the spec. Cc: Ashok Raj <[email protected]> Cc: Keith Busch <[email protected]> Suggested-by: Ashok Raj <[email protected]> Reviewed-by: Keith Busch <[email protected]> Signed-off-by: Kuppuswamy Sathyanarayanan <[email protected]> --- drivers/pci/ats.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index e7a904e347c3..718e6f414680 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -19,6 +19,7 @@ void pci_ats_init(struct pci_dev *dev) { int pos; + struct pci_dev *pdev; if (pci_ats_disabled()) return; @@ -27,6 +28,17 @@ void pci_ats_init(struct pci_dev *dev) if (!pos) return; + /* + * Per PCIe r4.0, sec 9.3.7.8, if VF implements Address Translation + * Services (ATS) Extended Capability then corresponding PF should + * also implement it. + */ + if (dev->is_virtfn) { + pdev = pci_physfn(dev); + if (!pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS)) + return; + } + dev->ats_cap = pos; } -- 2.20.1
