Messages in this thread | | | From | Lu Baolu <> | Subject | Re: iommu/vt-d: Cure VF irqdomain hickup | Date | Fri, 13 Nov 2020 15:20:55 +0800 |
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Hi Thomas,
On 2020/11/13 3:15, Thomas Gleixner wrote: > The recent changes to store the MSI irqdomain pointer in struct device > missed that Intel DMAR does not register virtual function devices. Due to > that a VF device gets the plain PCI-MSI domain assigned and then issues > compat MSI messages which get caught by the interrupt remapping unit. > > Cure that by inheriting the irq domain from the physical function > device. > > That's a temporary workaround. The correct fix is to inherit the irq domain > from the bus, but that's a larger effort which needs quite some other > changes to the way how x86 manages PCI and MSI domains. > > Fixes: 85a8dfc57a0b ("iommm/vt-d: Store irq domain in struct device") > Reported-by: Jason Gunthorpe <jgg@nvidia.com> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > --- > drivers/iommu/intel/dmar.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > --- a/drivers/iommu/intel/dmar.c > +++ b/drivers/iommu/intel/dmar.c > @@ -333,6 +333,11 @@ static void dmar_pci_bus_del_dev(struct > dmar_iommu_notify_scope_dev(info); > } > > +static inline void vf_inherit_msi_domain(struct pci_dev *pdev) > +{ > + dev_set_msi_domain(&pdev->dev, dev_get_msi_domain(&pdev->physfn->dev)); > +} > + > static int dmar_pci_bus_notifier(struct notifier_block *nb, > unsigned long action, void *data) > { > @@ -342,8 +347,20 @@ static int dmar_pci_bus_notifier(struct > /* Only care about add/remove events for physical functions. > * For VFs we actually do the lookup based on the corresponding > * PF in device_to_iommu() anyway. */ > - if (pdev->is_virtfn) > + if (pdev->is_virtfn) { > + /* > + * Note: This is a horrible hack and needs to be cleaned > + * up by assigning the domain to the bus, but that's too > + * big of a change for post rc3. > + * > + * Ensure that the VF device inherits the irq domain of the > + * PF device: > + */ > + if (action == BUS_NOTIFY_ADD_DEVICE) > + vf_inherit_msi_domain(pdev); > return NOTIFY_DONE; > + } > + > if (action != BUS_NOTIFY_ADD_DEVICE && > action != BUS_NOTIFY_REMOVED_DEVICE) > return NOTIFY_DONE;
We also encountered this problem in internal testing. This patch can solve the problem.
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Best regards, baolu
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