Re: [Qemu-devel] [PATCHv3 08/13] qemu: add support for resizing regions

Glauber Costa
2009-06-09T17:32:27Z

On Fri, Jun 05, 2009 at 01:23:55PM +0300, Michael S. Tsirkin wrote:
> Make it possible to resize PCI regions. This will be used by virtio
> with MSI-X, where the region size depends on whether MSI-X is enabled,
> and can change across load/save.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> hw/pci.c | 54 ++++++++++++++++++++++++++++++++++++------------------
> hw/pci.h | 3 +++
> 2 files changed, 39 insertions(+), 18 deletions(-)
>
> diff --git a/hw/pci.c b/hw/pci.c
> index ed011b5..042a216 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -392,6 +392,41 @@ void pci_register_io_region(PCIDevice *pci_dev, int region_num,
> *(uint32_t *)(pci_dev->wmask + addr) = cpu_to_le32(wmask);
> }
>
> +static void pci_unmap_region(PCIDevice *d, PCIIORegion *r)
> +{
> + if (r->addr == -1)
> + return;
> + if (r->type & PCI_ADDRESS_SPACE_IO) {
> + int class;
> + /* NOTE: specific hack for IDE in PC case:
> + only one byte must be mapped. */
> + class = pci_get_word(d->config + PCI_CLASS_DEVICE);
> + if (class == 0x0101 && r->size == 4) {
> + isa_unassign_ioport(r->addr + 2, 1);
> + } else {
> + isa_unassign_ioport(r->addr, r->size);
> + }
> + } else {
> + cpu_register_physical_memory(pci_to_cpu_addr(r->addr),
> + r->size,
> + IO_MEM_UNASSIGNED);
> + qemu_unregister_coalesced_mmio(r->addr, r->size);
> + }
> +}
> +
this is a good cleanup...

> +void pci_resize_io_region(PCIDevice *pci_dev, int region_num,
> + uint32_t size)
> +{
> +
> + PCIIORegion *r = &pci_dev->io_regions[region_num];
> + if (r->size == size)
> + return;
> + r->size = size;
> + pci_unmap_region(pci_dev, r);
> + r->addr = -1;
> + pci_update_mappings(pci_dev);
> +}
> +
but the only user of this one seem to be commented out, and later removed.
Why is this needed?