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path: root/hw/pci-bridge/pci_expander_bridge.c
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Diffstat (limited to 'hw/pci-bridge/pci_expander_bridge.c')
-rw-r--r--hw/pci-bridge/pci_expander_bridge.c44
1 files changed, 39 insertions, 5 deletions
diff --git a/hw/pci-bridge/pci_expander_bridge.c b/hw/pci-bridge/pci_expander_bridge.c
index e752a21292..ead33f0c05 100644
--- a/hw/pci-bridge/pci_expander_bridge.c
+++ b/hw/pci-bridge/pci_expander_bridge.c
@@ -15,6 +15,7 @@
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/pci/pci_host.h"
+#include "hw/pci/pcie_port.h"
 #include "hw/qdev-properties.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci-bridge/pci_expander_bridge.h"
@@ -79,6 +80,13 @@ CXLComponentState *cxl_get_hb_cstate(PCIHostState *hb)
     return &host->cxl_cstate;
 }
 
+bool cxl_get_hb_passthrough(PCIHostState *hb)
+{
+    CXLHost *host = PXB_CXL_HOST(hb);
+
+    return host->passthrough;
+}
+
 static int pxb_bus_num(PCIBus *bus)
 {
     PXBDev *pxb = convert_to_pxb(bus->parent_dev);
@@ -289,15 +297,32 @@ static int pxb_map_irq_fn(PCIDevice *pci_dev, int pin)
     return pin - PCI_SLOT(pxb->devfn);
 }
 
-static void pxb_dev_reset(DeviceState *dev)
+static void pxb_cxl_dev_reset(DeviceState *dev)
 {
     CXLHost *cxl = PXB_CXL_DEV(dev)->cxl.cxl_host_bridge;
     CXLComponentState *cxl_cstate = &cxl->cxl_cstate;
+    PCIHostState *hb = PCI_HOST_BRIDGE(cxl);
     uint32_t *reg_state = cxl_cstate->crb.cache_mem_registers;
     uint32_t *write_msk = cxl_cstate->crb.cache_mem_regs_write_mask;
+    int dsp_count = 0;
 
     cxl_component_register_init_common(reg_state, write_msk, CXL2_ROOT_PORT);
-    ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY, TARGET_COUNT, 8);
+    /*
+     * The CXL specification allows for host bridges with no HDM decoders
+     * if they only have a single root port.
+     */
+    if (!PXB_DEV(dev)->hdm_for_passthrough) {
+        dsp_count = pcie_count_ds_ports(hb->bus);
+    }
+    /* Initial reset will have 0 dsp so wait until > 0 */
+    if (dsp_count == 1) {
+        cxl->passthrough = true;
+        /* Set Capability ID in header to NONE */
+        ARRAY_FIELD_DP32(reg_state, CXL_HDM_CAPABILITY_HEADER, ID, 0);
+    } else {
+        ARRAY_FIELD_DP32(reg_state, CXL_HDM_DECODER_CAPABILITY, TARGET_COUNT,
+                         8);
+    }
 }
 
 static gint pxb_compare(gconstpointer a, gconstpointer b)
@@ -481,9 +506,18 @@ static void pxb_cxl_dev_realize(PCIDevice *dev, Error **errp)
     }
 
     pxb_dev_realize_common(dev, CXL, errp);
-    pxb_dev_reset(DEVICE(dev));
+    pxb_cxl_dev_reset(DEVICE(dev));
 }
 
+static Property pxb_cxl_dev_properties[] = {
+    /* Note: 0 is not a legal PXB bus number. */
+    DEFINE_PROP_UINT8("bus_nr", PXBDev, bus_nr, 0),
+    DEFINE_PROP_UINT16("numa_node", PXBDev, numa_node, NUMA_NODE_UNASSIGNED),
+    DEFINE_PROP_BOOL("bypass_iommu", PXBDev, bypass_iommu, false),
+    DEFINE_PROP_BOOL("hdm_for_passthrough", PXBDev, hdm_for_passthrough, false),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static void pxb_cxl_dev_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc   = DEVICE_CLASS(klass);
@@ -497,12 +531,12 @@ static void pxb_cxl_dev_class_init(ObjectClass *klass, void *data)
      */
 
     dc->desc = "CXL Host Bridge";
-    device_class_set_props(dc, pxb_dev_properties);
+    device_class_set_props(dc, pxb_cxl_dev_properties);
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
 
     /* Host bridges aren't hotpluggable. FIXME: spec reference */
     dc->hotpluggable = false;
-    dc->reset = pxb_dev_reset;
+    dc->reset = pxb_cxl_dev_reset;
 }
 
 static const TypeInfo pxb_cxl_dev_info = {