Currently only machine with CXL support upstream is i386/pc but arm/virt patches have been posted and once this is merged an updated series will follow. Switch support is queued behind this as well because they both include documentation updates.
Paolo Bonzini highlighted a couple of issues with the current CXL emulation code. * Top level parameter rather than machine for fixed memory windows The --cxl-fixed-memory-window top level command line parameters won't play well with efforts to make it possible to instantiate entire machines via RPC. Better to move these to be machine configuration. This change is relatively straight forward, but does result in very long command lines (cannot break fixed window setup into multiple -M entries). * Move all CXL stuff to machine specific code and helpers To simplify the various interactions between machine setup and host bridges etc, currently various CXL steps are called from the generic core/machine.c and softmmu/vl.c + there are CXL elements in MachineState. Much of this is straight forward to do with one exception: The CXL pci_expander_bridge host bridges require MMIO register space. This series does this by walking the bus and filling the register space in via the machine_done callback. This is similar to the walk done for identifying host bridges in the ACPI building code but it is rather ugly and postpones rejection of PXB_CXL instances where cxl=off (default). All comments welcome, but the first patch at least changes the command-line so to avoid have to add backwards compatibility code, it would be great to merge that before 7.1 is released. Run through the CI at: https://gitlab.com/jic23/qemu/-/pipelines/551206618 (rerunning a few test cases that timed out, but all passed for the full tree with arm/virt and switch support, so should be fine) Thanks, Jonathan Jonathan Cameron (8): hw/cxl: Make the CXL fixed memory window setup a machine parameter. hw/acpi/cxl: Pass in the CXLState directly rather than MachineState hw/cxl: Push linking of CXL targets into i386/pc rather than in machine.c tests/acpi: Allow modification of q35 CXL CEDT table. pci/pci_expander_bridge: For CXL HB delay the HB register memory region setup. tests/acpi: Update q35/CEDT.cxl for new memory addresses. hw/cxl: Move the CXLState from MachineState to machine type specific state. hw/machine: Drop cxl_supported flag as no longer useful docs/system/devices/cxl.rst | 4 +- hw/acpi/cxl.c | 9 +-- hw/core/machine.c | 28 ------- hw/cxl/cxl-host-stubs.c | 8 +- hw/cxl/cxl-host.c | 80 +++++++++++++++++--- hw/i386/acpi-build.c | 8 +- hw/i386/pc.c | 44 ++++++++--- hw/pci-bridge/meson.build | 5 +- hw/pci-bridge/pci_expander_bridge.c | 32 +++++--- hw/pci-bridge/pci_expander_bridge_stubs.c | 14 ++++ include/hw/acpi/cxl.h | 5 +- include/hw/boards.h | 3 +- include/hw/cxl/cxl.h | 9 +-- include/hw/cxl/cxl_host.h | 22 ++++++ include/hw/i386/pc.h | 2 + include/hw/pci-bridge/pci_expander_bridge.h | 12 +++ qapi/machine.json | 13 ++++ softmmu/vl.c | 46 ----------- tests/data/acpi/q35/CEDT.cxl | Bin 184 -> 184 bytes tests/qtest/bios-tables-test.c | 4 +- tests/qtest/cxl-test.c | 4 +- 21 files changed, 213 insertions(+), 139 deletions(-) create mode 100644 hw/pci-bridge/pci_expander_bridge_stubs.c create mode 100644 include/hw/cxl/cxl_host.h create mode 100644 include/hw/pci-bridge/pci_expander_bridge.h -- 2.32.0
