pci_add_capability appears most PCI devices. Its error handling required
lots of code, and led to inconsistent behaviors such as:
- passing error_abort
- passing error_fatal
- asserting the returned value
- propagating the error to the caller
- skipping the rest of the function
- just ignoring

The code generating errors in pci_add_capability had a comment which
says:
> Verify that capabilities don't overlap.  Note: device assignment
> depends on this check to verify that the device is not broken.
> Should never trigger for emulated devices, but it's helpful for
> debugging these.

Indeed vfio has some code that passes capability offsets and sizes from
a physical device, but it explicitly pays attention so that the
capabilities never overlap. Therefore, we can always assert that
capabilities never overlap when pci_add_capability is called, resolving
these inconsistencies.

v2: Split the patch (Markus Armbruster)

Akihiko Odaki (17):
  pci: Allow to omit errp for pci_add_capability
  hw/i386/amd_iommu: Omit errp for pci_add_capability
  ahci: Omit errp for pci_add_capability
  e1000e: Omit errp for pci_add_capability
  eepro100: Omit errp for pci_add_capability
  hw/nvme: Omit errp for pci_add_capability
  msi: Omit errp for pci_add_capability
  hw/pci/pci_bridge: Omit errp for pci_add_capability
  pcie: Omit errp for pci_add_capability
  pci/shpc: Omit errp for pci_add_capability
  msix: Omit errp for pci_add_capability
  pci/slotid: Omit errp for pci_add_capability
  hw/pci-bridge/pcie_pci_bridge: Omit errp for pci_add_capability
  hw/vfio/pci-quirks: Omit errp for pci_add_capability
  hw/vfio/pci: Omit errp for pci_add_capability
  virtio-pci: Omit errp for pci_add_capability
  pci: Remove legacy errp from pci_add_capability

 docs/pcie_sriov.txt                |  4 +--
 hw/display/bochs-display.c         |  4 +--
 hw/i386/amd_iommu.c                | 21 +++---------
 hw/ide/ich.c                       |  8 ++---
 hw/net/e1000e.c                    | 22 +++----------
 hw/net/eepro100.c                  |  7 +---
 hw/nvme/ctrl.c                     | 14 ++------
 hw/pci-bridge/cxl_downstream.c     |  9 ++----
 hw/pci-bridge/cxl_upstream.c       |  8 ++---
 hw/pci-bridge/i82801b11.c          | 14 ++------
 hw/pci-bridge/pci_bridge_dev.c     |  2 +-
 hw/pci-bridge/pcie_pci_bridge.c    | 19 +++--------
 hw/pci-bridge/pcie_root_port.c     | 16 ++-------
 hw/pci-bridge/xio3130_downstream.c | 15 ++-------
 hw/pci-bridge/xio3130_upstream.c   | 15 ++-------
 hw/pci-host/designware.c           |  3 +-
 hw/pci-host/xilinx-pcie.c          |  4 +--
 hw/pci/msi.c                       |  9 +-----
 hw/pci/msix.c                      |  8 ++---
 hw/pci/pci.c                       | 29 ++++-------------
 hw/pci/pci_bridge.c                | 21 ++++--------
 hw/pci/pcie.c                      | 52 ++++++++----------------------
 hw/pci/shpc.c                      | 23 ++++---------
 hw/pci/slotid_cap.c                |  8 ++---
 hw/usb/hcd-xhci-pci.c              |  3 +-
 hw/vfio/pci-quirks.c               | 15 ++-------
 hw/vfio/pci.c                      | 14 +++-----
 hw/virtio/virtio-pci.c             | 12 ++-----
 include/hw/pci/pci.h               |  5 ++-
 include/hw/pci/pci_bridge.h        |  5 ++-
 include/hw/pci/pcie.h              | 11 +++----
 include/hw/pci/shpc.h              |  3 +-
 include/hw/virtio/virtio-pci.h     |  2 +-
 33 files changed, 99 insertions(+), 306 deletions(-)

-- 
2.37.3