Re: [PATCH 00/32] Consolidate PIIX south bridges

["Michael S. Tsirkin" <mst@redhat.com>]

On Sun, Dec 04, 2022 at 08:05:21PM +0100, Bernhard Beschow wrote:
> This series consolidates the implementations of the PIIX3 and PIIX4 south
> bridges and is an extended version of [1]. The motivation is to share as much
> code as possible and to bring both device models to feature parity such that
> perhaps PIIX4 can become a drop-in-replacement for PIIX3 in the pc machine. This
> could resolve the "Frankenstein" PIIX4-PM problem in PIIX3 discussed on this
> list before.
> 
> The series is structured as follows: First, PIIX3 is changed to instantiate
> internal devices itself, like PIIX4 does already. Second, PIIX3 gets prepared
> for the merge with PIIX4 which includes some fixes, cleanups, and renamings.
> Third, the same is done for PIIX4. In step four the implementations are merged.
> Since some consolidations could be done easier with merged implementations, the
> consolidation continues in step five which concludes the series.
> 
> One particular challenge in this series was that the PIC of PIIX3 used to be
> instantiated outside of the south bridge while some sub functions require a PIC
> with populated qemu_irqs. This has been solved by introducing a proxy PIC which
> furthermore allows PIIX3 to be agnostic towards the virtualization technology
> used (KVM, TCG, Xen). Due to consolidation PIIX4 gained the proxy PIC as well.
> 
> Another challenge was dealing with optional devices where Peter already gave
> advice in [1] which this series implements.
> 
> A challenge still remains with consolidating PCI interrupt handling. There are
> still board-specific piix3_pci_slot_get_pirq() and piix4_pci_slot_get_pirq()
> which are implemented in isa/piix.c. Any advice how to resolve these would be
> highly appreaciated. See [2] for details.
> 
> Last but not least there might be some opportunity to consolidate VM state
> handling, probably by reusing the one from PIIX3. Since I'm not very familiar
> with the requirements I didn't touch it so far.
> 
> Testing done:
> * make check
> * make check-avocado
> * Boot live CD:
>   * `qemu-system-x86_64 -M pc -m 2G -accel kvm -cpu host -cdrom manjaro-kde-21.3.2-220704-linux515.iso`
>   * `qemu-system-x86_64 -M q35 -m 2G -accel kvm -cpu host -cdrom manjaro-kde-21.3.2-220704-linux515.iso`
> * 'qemu-system-mips64el -M malta -kernel vmlinux-3.2.0-4-5kc-malta -hda debian_wheezy_mipsel_standard.qcow2 -append "root=/dev/sda1 console=ttyS0"`
> 
> v3:
> - Introduce one TYPE_ICH9_USB_UHCI(fn) rather than several TYPE_ICH9_USB_UHCIx (Philippe)
> - Make proxy PIC generic (Philippe)
> - Track Malta's PIIX dependencies through KConfig
> - Rebase onto Philippe's 'hw/isa/piix4: Remove MIPS Malta specific bits' series [3]
> - Also rebase onto latest master to resolve merge conflicts. This required copying
>   Philippe's series as first three patches - please ignore.

So IIUC, you are waiting for Philippe to respin his series then
you can include it all in v4, right?


> v2:
> - Introduce TYPE_ defines for IDE and USB device models (Mark)
> - Omit unexporting of PIIXState (Mark)
> - Improve commit message of patch 5 to mention reset triggering through PCI
>   configuration space (Mark)
> - Move reviewed patches w/o dependencies to the bottom of the series for early
>   upstreaming
> 
> [1] https://lists.nongnu.org/archive/html/qemu-devel/2022-07/msg02348.html
> [2] https://lists.nongnu.org/archive/html/qemu-devel/2022-11/msg03310.html
> [3] https://lists.nongnu.org/archive/html/qemu-devel/2022-10/msg05367.html
> 
> Bernhard Beschow (29):
>   hw/mips/Kconfig: Track Malta's PIIX dependencies via Kconfig
>   hw/i386/pc_piix: Allow for setting properties before realizing PIIX3
>     south bridge
>   hw/usb/hcd-uhci: Introduce TYPE_ defines for device models
>   hw/i386/pc: Create RTC controllers in south bridges
>   hw/i386/pc: No need for rtc_state to be an out-parameter
>   hw/isa/piix3: Create USB controller in host device
>   hw/isa/piix3: Create power management controller in host device
>   hw/core: Introduce proxy-pic
>   hw/isa/piix3: Create Proxy PIC in host device
>   hw/isa/piix3: Create IDE controller in host device
>   hw/isa/piix3: Wire up ACPI interrupt internally
>   hw/isa/piix3: Resolve redundant PIIX_NUM_PIC_IRQS
>   hw/isa/piix3: Rename pci_piix3_props for sharing with PIIX4
>   hw/isa/piix3: Rename piix3_reset() for sharing with PIIX4
>   hw/isa/piix3: Prefix pci_slot_get_pirq() with "piix3_"
>   hw/isa/piix3: Rename typedef PIIX3State to PIIXState
>   hw/isa/piix4: Make PIIX4's ACPI and USB functions optional
>   hw/isa/piix4: Remove unused code
>   hw/isa/piix4: Use Proxy PIC device
>   hw/isa/piix4: Reuse struct PIIXState from PIIX3
>   hw/isa/piix4: Rename reset control operations to match PIIX3
>   hw/isa/piix4: Prefix pci_slot_get_pirq() with "piix4_"
>   hw/isa/piix3: Merge hw/isa/piix4.c
>   hw/isa/piix: Harmonize names of reset control memory regions
>   hw/isa/piix: Reuse PIIX3 base class' realize method in PIIX4
>   hw/isa/piix: Rename functions to be shared for interrupt triggering
>   hw/isa/piix: Consolidate IRQ triggering
>   hw/isa/piix: Share PIIX3 base class with PIIX4
>   hw/isa/piix: Drop the "3" from the PIIX base class
> 
> Philippe Mathieu-Daudé (3):
>   hw/mips/malta: Introduce PIIX4_PCI_DEVFN definition
>   hw/mips/malta: Set PIIX4 IRQ routes in embedded bootloader
>   hw/isa/piix4: Correct IRQRC[A:D] reset values
> 
>  MAINTAINERS                             |   8 +-
>  configs/devices/mips-softmmu/common.mak |   2 -
>  hw/core/Kconfig                         |   3 +
>  hw/core/meson.build                     |   1 +
>  hw/core/proxy-pic.c                     |  70 +++++
>  hw/i386/Kconfig                         |   4 +-
>  hw/i386/pc.c                            |  16 +-
>  hw/i386/pc_piix.c                       |  71 ++---
>  hw/i386/pc_q35.c                        |  16 +-
>  hw/isa/Kconfig                          |  10 +-
>  hw/isa/lpc_ich9.c                       |   8 +
>  hw/isa/meson.build                      |   3 +-
>  hw/isa/{piix3.c => piix.c}              | 302 +++++++++++++++++-----
>  hw/isa/piix4.c                          | 327 ------------------------
>  hw/mips/Kconfig                         |   2 +
>  hw/mips/malta.c                         |  38 ++-
>  hw/usb/hcd-uhci.c                       |  16 +-
>  hw/usb/hcd-uhci.h                       |   4 +
>  include/hw/core/proxy-pic.h             |  54 ++++
>  include/hw/i386/ich9.h                  |   2 +
>  include/hw/i386/pc.h                    |   2 +-
>  include/hw/southbridge/piix.h           |  30 ++-
>  22 files changed, 520 insertions(+), 469 deletions(-)
>  create mode 100644 hw/core/proxy-pic.c
>  rename hw/isa/{piix3.c => piix.c} (56%)
>  delete mode 100644 hw/isa/piix4.c
>  create mode 100644 include/hw/core/proxy-pic.h
> 
> -- 
> 2.38.1
>