pcie_sriov: Fix broken MMIO accesses from SR-IOV VFs

Starting with commit cab1398a60eb, SR-IOV VFs are realized as soon as
pcie_sriov_pf_init() is called.  Because pcie_sriov_pf_init() must be
called before pcie_sriov_pf_init_vf_bar(), the VF BARs types won't be
known when the VF realize function calls pcie_sriov_vf_register_bar().

This breaks the memory regions of the VFs (for instance with igbvf):

$ lspci
...
    Region 0: Memory at 281a00000 (64-bit, prefetchable) [virtual] [size=16K]
    Region 3: Memory at 281a20000 (64-bit, prefetchable) [virtual] [size=16K]

$ info mtree
...
address-space: pci_bridge_pci_mem
  0000000000000000-ffffffffffffffff (prio 0, i/o): pci_bridge_pci
    0000000081a00000-0000000081a03fff (prio 1, i/o): igbvf-mmio
    0000000081a20000-0000000081a23fff (prio 1, i/o): igbvf-msix

and causes MMIO accesses to fail:

    Invalid write at addr 0x281A01520, size 4, region '(null)', reason: rejected
    Invalid read at addr 0x281A00C40, size 4, region '(null)', reason: rejected

To fix this, VF BARs are now registered with pci_register_bar() which
has a type parameter and pcie_sriov_vf_register_bar() is removed.

Fixes: cab1398a60eb ("pcie_sriov: Reuse SR-IOV VF device instances")
Signed-off-by: Damien Bergamini <damien.bergamini@eviden.com>
Signed-off-by: Clement Mathieu--Drif <clement.mathieu--drif@eviden.com>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20250901151314.1038020-1-clement.mathieu--drif@eviden.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/docs/pcie_sriov.txt b/docs/pcie_sriov.txt
index ab2142807f..00d7bd93fd 100644
--- a/docs/pcie_sriov.txt
+++ b/docs/pcie_sriov.txt
@@ -72,8 +72,7 @@ setting up a BAR for a VF.
 2) Similarly in the implementation of the virtual function, you need to
    make it a PCI Express device and add a similar set of capabilities
    except for the SR/IOV capability. Then you need to set up the VF BARs as
-   subregions of the PFs SR/IOV VF BARs by calling
-   pcie_sriov_vf_register_bar() instead of the normal pci_register_bar() call:
+   subregions of the PFs SR/IOV VF BARs by calling pci_register_bar():
 
    pci_your_vf_dev_realize( ... )
    {
@@ -83,7 +82,7 @@ setting up a BAR for a VF.
       pcie_ari_init(d, 0x100);
       ...
       memory_region_init(mr, ... )
-      pcie_sriov_vf_register_bar(d, bar_nr, mr);
+      pci_register_bar(d, bar_nr, bar_type, mr);
       ...
    }