Re: [Qemu-devel] [PATCH 02/14] memory: Add MemTxAttrs, MemTxResult to io_mem_read and io_mem_write

[Paolo Bonzini]

On 08/04/2015 12:59, Peter Maydell wrote:
> Incidentally in the course of this patch I noticed that we have
> exactly two places outside the memory system that use these
> functions: hw/s390x/s390-pci-inst.c and hw/vfio/pci.c. Is
> this a reasonable thing, or should they in an ideal world
> have created an AddressSpace to access things through?

In the case of VFIO, I would just export pci_read/write_msix_table
functions from the PCI core.

In the case of s390 they would have to create an AddressSpace per BAR
per device: the current code doesn't work for BARs backed by a RAM
region, or with a complicated layout (aliases and the like).  This
reflects how s390 PCI is basically only used for VFIO, so it's passable:
having a separate AddressSpace per BAR per device probably wouldn't
scale too well.

Paolo

> (I have no opinion except that functions used in only one
> or two places always look a little suspicious to me :-))