[RFC PATCH 2/3] hw/arm/virt: Basic CXL enablement on pci_expander_bridge instances pxb-cxl

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

Code based on i386/pc enablement.
There is a small amount of directly cut and paste code so it may
make sense to unify that at some stage.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 hw/arm/Kconfig           |  1 +
 hw/arm/virt-acpi-build.c | 27 +++++++++++++++++++++++++++
 hw/arm/virt.c            |  3 ++-
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 0a242e4c5d..c43862bb23 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -27,6 +27,7 @@ config ARM_VIRT
     select ACPI_HW_REDUCED
     select ACPI_NVDIMM
     select ACPI_APEI
+    select ACPI_CXL
 
 config CHEETAH
     bool
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 9d9ee24053..ce7fd908d2 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -39,11 +39,13 @@
 #include "hw/acpi/aml-build.h"
 #include "hw/acpi/utils.h"
 #include "hw/acpi/pci.h"
+#include "hw/acpi/cxl.h"
 #include "hw/acpi/memory_hotplug.h"
 #include "hw/acpi/generic_event_device.h"
 #include "hw/acpi/tpm.h"
 #include "hw/pci/pcie_host.h"
 #include "hw/pci/pci.h"
+#include "hw/pci/pci_bus.h"
 #include "hw/pci-host/gpex.h"
 #include "hw/arm/virt.h"
 #include "hw/mem/nvdimm.h"
@@ -155,11 +157,27 @@ static void acpi_dsdt_add_virtio(Aml *scope,
     }
 }
 
+/* Move the i386 definition somewhere common? */
+static void build_acpi0017(Aml *table)
+{
+    Aml *dev;
+    Aml *scope;
+
+    scope =  aml_scope("_SB");
+    dev = aml_device("CXLM");
+    aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0017")));
+
+    aml_append(scope, dev);
+    aml_append(table, scope);
+}
+
 static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap,
                               uint32_t irq, bool use_highmem, bool highmem_ecam,
                               VirtMachineState *vms)
 {
     int ecam_id = VIRT_ECAM_ID(highmem_ecam);
+    bool cxl_present = false;
+    PCIBus *bus = vms->bus;
     struct GPEXConfig cfg = {
         .mmio32 = memmap[VIRT_PCIE_MMIO],
         .pio    = memmap[VIRT_PCIE_PIO],
@@ -173,6 +191,14 @@ static void acpi_dsdt_add_pci(Aml *scope, const MemMapEntry *memmap,
     }
 
     acpi_dsdt_add_gpex(scope, &cfg);
+    QLIST_FOREACH(bus, &vms->bus->child, sibling) {
+        if (pci_bus_is_cxl(bus)) {
+            cxl_present = true;
+        }
+    }
+    if (cxl_present) {
+        build_acpi0017(scope);
+    }
 }
 
 static void acpi_dsdt_add_gpio(Aml *scope, const MemMapEntry *gpio_memmap,
@@ -724,6 +750,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
             build_slit(tables_blob, tables->linker, ms);
         }
     }
+    cxl_build_cedt(table_offsets, tables_blob, tables->linker);
 
     if (ms->nvdimms_state->is_enabled) {
         nvdimm_build_acpi(table_offsets, tables_blob, tables->linker,
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index a3ac20744b..4d760beea9 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -78,6 +78,7 @@
 #include "hw/acpi/generic_event_device.h"
 #include "hw/virtio/virtio-iommu.h"
 #include "hw/char/pl011.h"
+#include "hw/cxl/cxl.h"
 #include "qemu/guest-random.h"
 
 #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
@@ -2481,7 +2482,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
     hc->unplug_request = virt_machine_device_unplug_request_cb;
     hc->unplug = virt_machine_device_unplug_cb;
     mc->nvdimm_supported = true;
-    mc->cxl_supported = false;
+    mc->cxl_supported = true;
     mc->auto_enable_numa_with_memhp = true;
     mc->auto_enable_numa_with_memdev = true;
     mc->default_ram_id = "mach-virt.ram";
-- 
2.19.1