[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3] VT-d: fix VF of RC integrated PF matched to wrong VT-d unit
On Thu, Jun 29, 2017 at 04:42:33PM +0100, Roger Pau Monné wrote: >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.Crawford@xxxxxxxxx> >> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx> >> --- >> 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. Yes. Thank you, Roger. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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