On 25.02.2022 14:50, Alex Olson wrote: > I realize PVH for dom0 is still experimental, but was trying to see how well > it > works in the state of "master". > > I found one issue with MSI-X interrupts in dom0 -- a fatal page fault occurs > when the MSI-X PBA is accessed from dom0. It looks like dom0 doesn't have an > identity mapping for the PBA of a PCI device -- intentionally caused by > vpci_make_msix_hole() ? > > I was also wondering, what is the impact of "existing mapping (...) at 0 > clobbers MSIX MMIO area". > > Is the purpose of vpci_make_msix_hole() to make MSIX table/PBA accesses trap > to > the hypervisor? Seems like the page-based granularity is too coarse since the > PBA can be much smaller than a page as well as not aligned... > > I was able to get something potentially usable by adding a "ioremap" call in > msix_read() and msix_write to deal with the access of the PBA. Wasn't sure > if > this was a proper way of handling things... Was also wondering if it would > make > sense to do the same for the "clobbers MSIX MMIO area" cases too.
You happen to ask just over two hours after a patch was posted: https://lists.xen.org/archives/html/xen-devel/2022-02/msg01657.html Since Roger didn't have an environment to test his change, maybe you could do so, offering a Tested-by if successful? Jan
