The problem is for a VF of RC integrated PF (e.g. PF's BDF is 00:02.0), we would wrongly use 00:00.0 to search VT-d unit.
From SRIOV spec REV 1.0 section 3.7.3, it says: "ARI is not applicable to Root Complex integrated Endpoints; all other SR-IOV Capable Devices (Devices that include at least one PF) shall implement the ARI Capability in each Function.". So PFs can be classified to two kinds: one is RC integrated PF and the other is non-RC integrated PF. The former can't support ARI and the latter shall support ARI. For Extended Functions, one traditional function's BDF should be used to search VT-d unit. And according to PCIe spec, Extened Function means within an ARI device, a Function whose Function Number is greater than 7. Thus, the former can't be an extended function, while the latter is as long as its devfn > 7, this check is exactly what the original code did; The original code wasn't aware the former. This patch directly looks up the 'is_extfn' field of PF's struct pci_dev to decide whether the PF is a extended function. Reported-by: Crawford, Eric R <eric.r.crawf...@intel.com> Signed-off-by: Chao Gao <chao....@intel.com> --- xen/drivers/passthrough/vtd/dmar.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c index 82040dd..27ff471 100644 --- a/xen/drivers/passthrough/vtd/dmar.c +++ b/xen/drivers/passthrough/vtd/dmar.c @@ -218,8 +218,17 @@ struct acpi_drhd_unit *acpi_find_matched_drhd_unit(const struct pci_dev *pdev) } else if ( pdev->info.is_virtfn ) { + struct pci_dev *physfn; + bus = pdev->info.physfn.bus; - devfn = PCI_SLOT(pdev->info.physfn.devfn) ? 0 : pdev->info.physfn.devfn; + /* + * Use 0 as 'devfn' to search VT-d unit when the physical function + * is an Extended Function. + */ + pcidevs_lock(); + physfn = pci_get_pdev(pdev->seg, bus, pdev->info.physfn.devfn); + pcidevs_unlock(); + devfn = (physfn && physfn->info.is_extfn) ? 0 : pdev->info.physfn.devfn; } else { -- 1.8.3.1 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel