| Message ID | 20220826121141.50743-5-baolu.lu@linux.intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | iommu: SVA and IOPF refactoring | expand |
On Fri, Aug 26, 2022 at 08:11:28PM +0800, Lu Baolu wrote: > The Requester ID/Process Address Space ID (PASID) combination > identifies an address space distinct from the PCI bus address space, > e.g., an address space defined by an IOMMU. > > But the PCIe fabric routes Memory Requests based on the TLP address, > ignoring any PASID (PCIe r6.0, sec 2.2.10.4), so a TLP with PASID that > SHOULD go upstream to the IOMMU may instead be routed as a P2P > Request if its address falls in a bridge window. > > To ensure that all Memory Requests with PASID are routed upstream, > only enable PASID if ACS P2P Request Redirect and Upstream Forwarding > are enabled for the path leading to the device. > > Suggested-by: Jason Gunthorpe <jgg@nvidia.com> > Suggested-by: Kevin Tian <kevin.tian@intel.com> > Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> > Acked-by: Bjorn Helgaas <bhelgaas@google.com> > Tested-by: Tony Zhu <tony.zhu@intel.com> > --- > drivers/pci/ats.c | 3 +++ > 1 file changed, 3 insertions(+) Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Jason
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index c967ad6e2626..f9cc2e10b676 100644 --- a/drivers/pci/ats.c +++ b/drivers/pci/ats.c @@ -382,6 +382,9 @@ int pci_enable_pasid(struct pci_dev *pdev, int features) if (!pasid) return -EINVAL; + if (!pci_acs_path_enabled(pdev, NULL, PCI_ACS_RR | PCI_ACS_UF)) + return -EINVAL; + pci_read_config_word(pdev, pasid + PCI_PASID_CAP, &supported); supported &= PCI_PASID_CAP_EXEC | PCI_PASID_CAP_PRIV;