Messages in this thread Patch in this message | | | From | sathyanarayanan.kuppuswamy@linux ... | Subject | [PATCH v2 3/5] PCI/ATS: Skip VF ATS initialization if PF does not implement it | Date | Mon, 6 May 2019 10:20:05 -0700 |
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From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
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 <ashok.raj@intel.com> Cc: Keith Busch <keith.busch@intel.com> Suggested-by: Ashok Raj <ashok.raj@intel.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> --- 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
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