On Mon, 7 Sep 2026 17:37:28 +0800 Chen Pei <[email protected]> wrote:
> Enable CXL support on the RISC-V virt machine following the same > approach used by the ARM virt machine: > - Add PXB and ACPI_CXL Kconfig selections > - Add CXLState and PCIBus pointer to RISCVVirtState > - Register CXL machine properties via cxl_machine_init() > - Create CXL host register region above the PCIe high MMIO region > - Call cxl_hook_up_pxb_registers() and cxl_fmws_link_targets() at > machine_done time > - Map Fixed Memory Windows above the CXL host register region > - Add ACPI0017 device in DSDT and build CEDT table in virt-acpi-build.c > > Reviewed-by: Junjie Cao <[email protected]> > Tested-by: Junjie Cao <[email protected]> > Signed-off-by: Chen Pei <[email protected]> Sorry for delay. LGTM Reviewed-by: Jonathan Cameron <[email protected]> > --- > hw/riscv/Kconfig | 2 ++ > hw/riscv/virt-acpi-build.c | 20 ++++++++++++++++ > hw/riscv/virt.c | 47 ++++++++++++++++++++++++++++++++++---- > include/hw/riscv/virt.h | 3 +++ > 4 files changed, 68 insertions(+), 4 deletions(-) > > diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig > index d06ac26648..c2f8c5d2da 100644 > --- a/hw/riscv/Kconfig > +++ b/hw/riscv/Kconfig > @@ -66,8 +66,10 @@ config RISCV_VIRT > select VIRTIO_MMIO > select FW_CFG_DMA > select PLATFORM_BUS > + select PXB > select ACPI > select ACPI_PCI > + select ACPI_CXL > > config SHAKTI_C > bool > diff --git a/hw/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c > index 8e516ec114..2be8c6d572 100644 > --- a/hw/riscv/virt-acpi-build.c > +++ b/hw/riscv/virt-acpi-build.c > @@ -29,12 +29,16 @@ > #include "hw/acpi/aml-build.h" > #include "hw/acpi/pci.h" > #include "hw/acpi/utils.h" > +#include "hw/acpi/cxl.h" > #include "hw/intc/riscv_aclint.h" > #include "hw/nvram/fw_cfg_acpi.h" > #include "hw/pci-host/gpex.h" > +#include "hw/pci/pci_bus.h" > #include "hw/riscv/virt.h" > #include "hw/riscv/numa.h" > #include "hw/virtio/virtio-acpi.h" > +#include "hw/cxl/cxl.h" > +#include "hw/cxl/cxl_host.h" > #include "kvm/kvm_riscv.h" > #include "migration/vmstate.h" > #include "qapi/error.h" > @@ -518,6 +522,17 @@ static void build_dsdt(GArray *table_data, > acpi_dsdt_add_gpex_host(scope, PCIE_IRQ + s->num_sources * 2); > } > > + if (s->cxl_devices_state.is_enabled) { > + Aml *cxl_dev = aml_device("CXLM"); > + aml_append(cxl_dev, aml_name_decl("_HID", aml_string("ACPI0017"))); > + Aml *method = aml_method("_STA", 0, AML_NOTSERIALIZED); > + aml_append(method, aml_return(aml_int(0x0B))); > + aml_append(cxl_dev, method); > + build_cxl_dsm_method(cxl_dev); > + > + aml_append(scope, cxl_dev); > + } > + > aml_append(dsdt, scope); > > /* copy AML table into ACPI tables blob and patch header there */ > @@ -925,6 +940,11 @@ static void virt_acpi_build(RISCVVirtState *s, > AcpiBuildTables *tables) > s->oem_table_id); > } > > + if (s->cxl_devices_state.is_enabled) { > + cxl_build_cedt(table_offsets, tables_blob, tables->linker, > + s->oem_id, s->oem_table_id, &s->cxl_devices_state); > + } > + > if (ms->numa_state->num_nodes > 0) { > acpi_add_table(table_offsets, tables_blob); > build_srat(tables_blob, tables->linker, s); > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c > index f3a1cc5ba3..70090ca70a 100644 > --- a/hw/riscv/virt.c > +++ b/hw/riscv/virt.c > @@ -56,6 +56,8 @@ > #include "hw/pci/pci.h" > #include "hw/pci-host/gpex.h" > #include "hw/display/ramfb.h" > +#include "hw/cxl/cxl.h" > +#include "hw/cxl/cxl_host.h" > #include "hw/acpi/aml-build.h" > #include "qapi/qapi-visit-common.h" > #include "hw/virtio/virtio-iommu.h" > @@ -540,6 +542,29 @@ static void create_fdt(RISCVVirtState *s) > create_fdt_pmu(s); > } > > +static void cxl_host_state_init(RISCVVirtState *s) > +{ > + MemoryRegion *sysmem = get_system_memory(); > + MemoryRegion *mr = &s->cxl_devices_state.host_mr; > + hwaddr base; > + > + if (!s->cxl_devices_state.is_enabled) { > + return; > + } > + > + base = virt_high_pcie_memmap.base + virt_high_pcie_memmap.size; > + base = ROUND_UP(base, 64 * KiB); > + > + memory_region_init(mr, OBJECT(s), "cxl_host_reg", 64 * KiB * 16); > + memory_region_add_subregion(sysmem, base, mr); > + > + /* Map the Fixed Memory Windows above the CXL host register region. */ > + base += memory_region_size(mr); > + base = ROUND_UP(base, 256 * MiB); > + cxl_fmws_set_memmap(base, UINT64_MAX); > + cxl_fmws_update_mmio(); > +} > + > static FWCfgState *create_fw_cfg(const MachineState *ms, hwaddr base) > { > FWCfgState *fw_cfg; > @@ -625,6 +650,13 @@ static void virt_machine_done(Notifier *notifier, void > *data) > BlockBackend *pflash_blk0; > RISCVBootInfo boot_info; > > + cxl_hook_up_pxb_registers(s->pci_bus, &s->cxl_devices_state, > + &error_fatal); > + > + if (s->cxl_devices_state.is_enabled) { > + cxl_fmws_link_targets(&error_fatal); > + } > + > /* > * An user provided dtb must include everything, including > * dynamic sysbus devices. Our FDT needs to be finalized. > @@ -716,6 +748,7 @@ static void virt_machine_init(MachineState *machine) > MemoryRegion *system_memory = get_system_memory(); > MemoryRegion *mask_rom = g_new(MemoryRegion, 1); > DeviceState *mmio_irqchip, *virtio_irqchip, *pcie_irqchip; > + DeviceState *gpex_dev; > int i, base_hartid, hart_count; > int socket_count = riscv_socket_count(machine); > > @@ -871,6 +904,8 @@ static void virt_machine_init(MachineState *machine) > ROUND_UP(virt_high_pcie_memmap.base, virt_high_pcie_memmap.size); > } > > + cxl_host_state_init(s); > + > /* register system main memory (actual RAM) */ > memory_region_add_subregion(system_memory, s->memmap[VIRT_DRAM].base, > machine->ram); > @@ -898,10 +933,12 @@ static void virt_machine_init(MachineState *machine) > qdev_get_gpio_in(virtio_irqchip, VIRTIO_IRQ + i)); > } > > - riscv_gpex_pcie_init(system_memory, pcie_irqchip, > - &s->memmap[VIRT_PCIE_ECAM], &s->memmap[VIRT_PCIE_MMIO], > - &virt_high_pcie_memmap, &s->memmap[VIRT_PCIE_PIO], > - PCIE_IRQ); > + gpex_dev = riscv_gpex_pcie_init(system_memory, pcie_irqchip, > + &s->memmap[VIRT_PCIE_ECAM], > + &s->memmap[VIRT_PCIE_MMIO], > + &virt_high_pcie_memmap, > + &s->memmap[VIRT_PCIE_PIO], PCIE_IRQ); > + s->pci_bus = PCI_HOST_BRIDGE(gpex_dev)->bus; > > s->platform_bus_dev = riscv_create_platform_bus(mmio_irqchip, > &s->memmap[VIRT_PLATFORM_BUS], VIRT_PLATFORM_BUS_IRQ, > @@ -972,6 +1009,8 @@ static void virt_machine_instance_init(Object *obj) > s->acpi = ON_OFF_AUTO_AUTO; > s->iommu_sys = ON_OFF_AUTO_AUTO; > s->num_sources = VIRT_IRQCHIP_NUM_SOURCES; > + > + cxl_machine_init(obj, &s->cxl_devices_state); > } > > static char *virt_get_aia_guests(Object *obj, Error **errp) > diff --git a/include/hw/riscv/virt.h b/include/hw/riscv/virt.h > index e516898f9a..a7b74d10c6 100644 > --- a/include/hw/riscv/virt.h > +++ b/include/hw/riscv/virt.h > @@ -24,6 +24,7 @@ > #include "hw/core/sysbus.h" > #include "hw/block/flash.h" > #include "hw/intc/riscv_imsic.h" > +#include "hw/cxl/cxl.h" > > #define VIRT_CPUS_MAX_BITS 9 > #define VIRT_CPUS_MAX (1 << VIRT_CPUS_MAX_BITS) > @@ -66,6 +67,8 @@ struct RISCVVirtState { > OnOffAuto iommu_sys; > uint16_t pci_iommu_bdf; > uint16_t num_sources; > + CXLState cxl_devices_state; > + PCIBus *pci_bus; > }; > > enum {
