Hi Le, On 2014-07-01 04:34, Le Tan wrote: > Hi Jan, > I use pci_setup_iommu() to setup a PCIIOMMUFunc for the q35 pci bus. > In the iommu_fn, I print out the devfn parameter and find out that it > sometimes will be -1. So what does it mean? > The detail code is here: > > In mch_init() function, I write like this: > PCIBus *pci_bus = PCI_BUS(qdev_get_parent_bus(DEVICE(mch))); > pci_setup_iommu(pci_bus, q35_host_dma_iommu, mch->iommu); > > And in q35_host_dma_iommu(PCIBus *bus, void *opaque, int devfn), I > print out the devfn parameter, sometimes it will be -1.
Hmm, I have no idea about the reason and would suggest to set a conditional breakpoint on this function, then print the backtrace to see where this comes from and analyze the device structure from where that -1 was most probably taken. Jan
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