On sPAPR, virtio devices are connected to the PCI bus and use MSI-X.
Commit cc943c36fa has modified MSI-X
so that writes are made using the bus master address space and follow
the IOMMU path.
Unfortunately, the IOMMU address space address space does not have an
MSI window: the notification is silently dropped in unassigned_mem_write
instead of reaching the guest... The most visible effect is that all
virtio devices are non-functional on sPAPR since then. :(
This patch does the following:
1) map the MSI window into the IOMMU address space for each PHB
- since each PHB instantiates its own IOMMU address space, we
can safely map the window at a fixed address (SPAPR_PCI_MSI_WINDOW)
- no real need to keep the MSI window setup in a separate function,
the spapr_pci_msi_init() code moves to spapr_phb_realize().
2) kill the global MSI window as it is not needed in the end
Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
(cherry picked from commit 8c46f7ec85)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
0824ca6bd1