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Jamin LinandCédric Le Goater
ba6fb09048
Introduce PCIe config (H2X) support for the AST2700 SoC. Unlike the AST2600, the AST2700 provides three independent Root Complexes, each with its own H2X (AHB to PCIe bridge) register block of size 0x100. All RCs use the same MSI address (0x000000F0). The H2X block includes two different access paths: 1. CFGI (internal bridge): used to access the host bridge itself, always with BDF=0. The AST2700 controller simplifies the design by exposing only one register (H2X_CFGI_TLP) with fields for ADDR[15:0], BEN[19:16], and WR[20]. This is not a full TLP descriptor as in the external case. For QEMU readability and code reuse, the model converts H2X_CFGI_TLP into a standard TLP TX descriptor with BDF forced to 0 and then calls the existing helpers aspeed_pcie_cfg_readwrite() and aspeed_pcie_cfg_translate_write(). 2. CFGE (external EP access): used to access external endpoints. The AST2700 design provides H2X_CFGE_TLP1 and a small FIFO at H2X_CFGE_TLPN. For reads, TX DESC0 is stored in TLP1 and DESC1/DESC2 in TLPN FIFO slots. For writes, TX DESC0 is stored in TLP1, DESC1/DESC2 in TLPN FIFO[0..1], and TX write data in TLPN FIFO[2]. The implementation extends AspeedPCIECfgState with a small FIFO and index, wires up new register definitions for AST2700, and adds a specific ops table and class (TYPE_ASPEED_2700_PCIE_CFG). The reset handler clears the FIFO state. Interrupt and MSI status registers are also supported. This provides enough modeling for firmware and drivers to use any of the three PCIe RCs on AST2700 with their own dedicated H2X config window, while reusing existing TLP decode helpers in QEMU. Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com> Reviewed-by: Cédric Le Goater <clg@redhat.com> Link: https://lore.kernel.org/qemu-devel/20250919093017.338309-11-jamin_lin@aspeedtech.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
=========== QEMU README =========== QEMU is a generic and open source machine & userspace emulator and virtualizer. QEMU is capable of emulating a complete machine in software without any need for hardware virtualization support. By using dynamic translation, it achieves very good performance. QEMU can also integrate with the Xen and KVM hypervisors to provide emulated hardware while allowing the hypervisor to manage the CPU. With hypervisor support, QEMU can achieve near native performance for CPUs. When QEMU emulates CPUs directly it is capable of running operating systems made for one machine (e.g. an ARMv7 board) on a different machine (e.g. an x86_64 PC board). QEMU is also capable of providing userspace API virtualization for Linux and BSD kernel interfaces. This allows binaries compiled against one architecture ABI (e.g. the Linux PPC64 ABI) to be run on a host using a different architecture ABI (e.g. the Linux x86_64 ABI). This does not involve any hardware emulation, simply CPU and syscall emulation. QEMU aims to fit into a variety of use cases. It can be invoked directly by users wishing to have full control over its behaviour and settings. It also aims to facilitate integration into higher level management layers, by providing a stable command line interface and monitor API. It is commonly invoked indirectly via the libvirt library when using open source applications such as oVirt, OpenStack and virt-manager. QEMU as a whole is released under the GNU General Public License, version 2. For full licensing details, consult the LICENSE file. Documentation ============= Documentation can be found hosted online at `<https://www.qemu.org/documentation/>`_. The documentation for the current development version that is available at `<https://www.qemu.org/docs/master/>`_ is generated from the ``docs/`` folder in the source tree, and is built by `Sphinx <https://www.sphinx-doc.org/en/master/>`_. Building ======== QEMU is multi-platform software intended to be buildable on all modern Linux platforms, OS-X, Win32 (via the Mingw64 toolchain) and a variety of other UNIX targets. The simple steps to build QEMU are: .. code-block:: shell mkdir build cd build ../configure make Additional information can also be found online via the QEMU website: * `<https://wiki.qemu.org/Hosts/Linux>`_ * `<https://wiki.qemu.org/Hosts/Mac>`_ * `<https://wiki.qemu.org/Hosts/W32>`_ Submitting patches ================== The QEMU source code is maintained under the GIT version control system. .. code-block:: shell git clone https://gitlab.com/qemu-project/qemu.git When submitting patches, one common approach is to use 'git format-patch' and/or 'git send-email' to format & send the mail to the qemu-devel@nongnu.org mailing list. All patches submitted must contain a 'Signed-off-by' line from the author. Patches should follow the guidelines set out in the `style section <https://www.qemu.org/docs/master/devel/style.html>`_ of the Developers Guide. Additional information on submitting patches can be found online via the QEMU website: * `<https://wiki.qemu.org/Contribute/SubmitAPatch>`_ * `<https://wiki.qemu.org/Contribute/TrivialPatches>`_ The QEMU website is also maintained under source control. .. code-block:: shell git clone https://gitlab.com/qemu-project/qemu-web.git * `<https://www.qemu.org/2017/02/04/the-new-qemu-website-is-up/>`_ A 'git-publish' utility was created to make above process less cumbersome, and is highly recommended for making regular contributions, or even just for sending consecutive patch series revisions. It also requires a working 'git send-email' setup, and by default doesn't automate everything, so you may want to go through the above steps manually for once. For installation instructions, please go to: * `<https://github.com/stefanha/git-publish>`_ The workflow with 'git-publish' is: .. code-block:: shell $ git checkout master -b my-feature $ # work on new commits, add your 'Signed-off-by' lines to each $ git publish Your patch series will be sent and tagged as my-feature-v1 if you need to refer back to it in the future. Sending v2: .. code-block:: shell $ git checkout my-feature # same topic branch $ # making changes to the commits (using 'git rebase', for example) $ git publish Your patch series will be sent with 'v2' tag in the subject and the git tip will be tagged as my-feature-v2. Bug reporting ============= The QEMU project uses GitLab issues to track bugs. Bugs found when running code built from QEMU git or upstream released sources should be reported via: * `<https://gitlab.com/qemu-project/qemu/-/issues>`_ If using QEMU via an operating system vendor pre-built binary package, it is preferable to report bugs to the vendor's own bug tracker first. If the bug is also known to affect latest upstream code, it can also be reported via GitLab. For additional information on bug reporting consult: * `<https://wiki.qemu.org/Contribute/ReportABug>`_ ChangeLog ========= For version history and release notes, please visit `<https://wiki.qemu.org/ChangeLog/>`_ or look at the git history for more detailed information. Contact ======= The QEMU community can be contacted in a number of ways, with the two main methods being email and IRC: * `<mailto:qemu-devel@nongnu.org>`_ * `<https://lists.nongnu.org/mailman/listinfo/qemu-devel>`_ * #qemu on irc.oftc.net Information on additional methods of contacting the community can be found online via the QEMU website: * `<https://wiki.qemu.org/Contribute/StartHere>`_