Re: [RFC PATCH] iommu/arm-smmu-v3: Allow nested attach for PCI bridges without vDEVICE
Dmitry Malkin <[email protected]>
| Newsgroups | dev.linux.lists.regressions,dev.linux.lists.iommu,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-kernel,org.kernel.vger.stable |
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> This kind of situation is very challenging to setup in the VM, and at > this point you may as well include the switch to the VM too. Passing through the PCI switch would not help because the device without a vDEVICE is the host Root Port. Neither the Root Port nor the switch should be exposed to the VM. A multi-device IOMMU group is an intentional effect of using 'pci=config_acs', and I would prefer to restore support for this configuration upstream. Dmitry