Re: [PATCH 1/1] virtio-pci: fix memory_region_find for VirtIOPCIRegion's MR

[David Hildenbrand]

On 24.09.24 03:11, Gao Shiyuan wrote:

Make sure to version your patch series. For example, via
        $ git format-patch -v1 ...

> As shown below, if a virtio PCI device is attached under a pci-bridge, the MR
> of VirtIOPCIRegion does not belong to any address space. So memory_region_find
> cannot be used to search for this MR.

I'm starting to wonder if memory_region_find() is really the right fun

> Introduce the virtio-pci and pci_bridge_pci address spaces to solve this 
> problem.
>
> Before:
> memory-region: pci_bridge_pci
>    0000000000000000-ffffffffffffffff (prio 0, i/o): pci_bridge_pci
>      00000000fe200000-00000000fe200fff (prio 1, i/o): virtio-blk-pci-msix
>        00000000fe200000-00000000fe20016f (prio 0, i/o): msix-table
>        00000000fe200800-00000000fe200807 (prio 0, i/o): msix-pba
>      000000a000400000-000000a000403fff (prio 1, i/o): virtio-pci
>        000000a000400000-000000a000400fff (prio 0, i/o): 
> virtio-pci-common-virtio-blk
>        000000a000401000-000000a000401fff (prio 0, i/o): 
> virtio-pci-isr-virtio-blk
>        000000a000402000-000000a000402fff (prio 0, i/o): 
> virtio-pci-device-virtio-blk
>        000000a000403000-000000a000403fff (prio 0, i/o): 
> virtio-pci-notify-virtio-blk
>
> After:
> address-space: pci_bridge_pci
>    0000000000000000-ffffffffffffffff (prio 0, i/o): pci_bridge_pci
>      00000000fe200000-00000000fe200fff (prio 1, i/o): virtio-blk-pci-msix
>        00000000fe200000-00000000fe20016f (prio 0, i/o): msix-table
>        00000000fe200800-00000000fe200807 (prio 0, i/o): msix-pba
>      000000a000400000-000000a000403fff (prio 1, i/o): virtio-pci
>        000000a000400000-000000a000400fff (prio 0, i/o): 
> virtio-pci-common-virtio-blk
>        000000a000401000-000000a000401fff (prio 0, i/o): 
> virtio-pci-isr-virtio-blk
>        000000a000402000-000000a000402fff (prio 0, i/o): 
> virtio-pci-device-virtio-blk
>        000000a000403000-000000a000403fff (prio 0, i/o): 
> virtio-pci-notify-virtio-blk
>
> address-space: virtio-pci
>    000000a000400000-000000a000403fff (prio 1, i/o): virtio-pci
>      000000a000400000-000000a000400fff (prio 0, i/o): 
> virtio-pci-common-virtio-blk
>      000000a000401000-000000a000401fff (prio 0, i/o): virtio-pci-isr-virtio-blk
>      000000a000402000-000000a000402fff (prio 0, i/o): 
> virtio-pci-device-virtio-blk
>      000000a000403000-000000a000403fff (prio 0, i/o): 
> virtio-pci-notify-virtio-blk
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2576
> Fixes: ffa8a3e ("virtio-pci: Add lookup subregion of VirtIOPCIRegion MR")

Commit id is not unique. Use 12 digits please.

I'm still not quite sure if memory_region_find() is really the right 
thing to use here, but I'm no expert on that so I'm hoping virtio/PCI 
people can review.

--
Cheers,

David / dhildenb