virtio-pci: fix memory_region_find for VirtIOPCIRegion's MR

virtio-pci: fix memory_region_find for VirtIOPCIRegion's MR

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.

Introduce the virtio-pci and pci_bridge address spaces to solve this problem.

Before:
memory-region: pci_bridge_pci
  0000000000000000-ffffffffffffffff (prio 0, i/o): pci_bridge_pci
    00000000fe840000-00000000fe840fff (prio 1, i/o): virtio-net-pci-msix
      00000000fe840000-00000000fe84003f (prio 0, i/o): msix-table
      00000000fe840800-00000000fe840807 (prio 0, i/o): msix-pba
    0000380000000000-0000380000003fff (prio 1, i/o): virtio-pci
      0000380000000000-0000380000000fff (prio 0, i/o): virtio-pci-common-virtio-net
      0000380000001000-0000380000001fff (prio 0, i/o): virtio-pci-isr-virtio-net
      0000380000002000-0000380000002fff (prio 0, i/o): virtio-pci-device-virtio-net
      0000380000003000-0000380000003fff (prio 0, i/o): virtio-pci-notify-virtio-net

After:
address-space: virtio-pci-cfg-mem-as
  0000380000000000-0000380000003fff (prio 1, i/o): virtio-pci
    0000380000000000-0000380000000fff (prio 0, i/o): virtio-pci-common-virtio-net
    0000380000001000-0000380000001fff (prio 0, i/o): virtio-pci-isr-virtio-net
    0000380000002000-0000380000002fff (prio 0, i/o): virtio-pci-device-virtio-net
    0000380000003000-0000380000003fff (prio 0, i/o): virtio-pci-notify-virtio-net

address-space: pci_bridge_pci_mem
  0000000000000000-ffffffffffffffff (prio 0, i/o): pci_bridge_pci
    00000000fe840000-00000000fe840fff (prio 1, i/o): virtio-net-pci-msix
      00000000fe840000-00000000fe84003f (prio 0, i/o): msix-table
      00000000fe840800-00000000fe840807 (prio 0, i/o): msix-pba
    0000380000000000-0000380000003fff (prio 1, i/o): virtio-pci
      0000380000000000-0000380000000fff (prio 0, i/o): virtio-pci-common-virtio-net
      0000380000001000-0000380000001fff (prio 0, i/o): virtio-pci-isr-virtio-net
      0000380000002000-0000380000002fff (prio 0, i/o): virtio-pci-device-virtio-net
      0000380000003000-0000380000003fff (prio 0, i/o): virtio-pci-notify-virtio-net

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2576
Fixes: ffa8a3e3b2e6 ("virtio-pci: Add lookup subregion of VirtIOPCIRegion MR")
Co-developed-by: Zuo Boqun <zuoboqun@baidu.com>
Signed-off-by: Zuo Boqun <zuoboqun@baidu.com>
Co-developed-by: Wang Liang <wangliang44@baidu.com>
Signed-off-by: Wang Liang <wangliang44@baidu.com>
Signed-off-by: Gao Shiyuan <gaoshiyuan@baidu.com>
Message-Id: <20241030131324.34144-1-gaoshiyuan@baidu.com>
Tested-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>