On Thu, Jun 29, 2017 at 11:21:53AM +0800, Chao Gao wrote: > 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;
AFAICT you should only release the pcidevs lock when you are done with the device, so that a concurrent call to pci_remove_device doesn't free the device while you are poking at it. Roger. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel