On 30.09.24 16:00, Michael S. Tsirkin wrote:
On Tue, Sep 24, 2024 at 02:31:20PM +0200, David Hildenbrand wrote:
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.
I donnu, what would you use?
I assume there is currently not better alternative. Scanning all address
spaces to find+walk a flatview sounds quite wasteful during each
virtio_address_space_lookup ...
So this change here looks ok to me for the time being.
--
Cheers,
David / dhildenb
