diff --git a/include/hw/pci-host/pnv_phb4.h b/include/hw/pci-host/pnv_phb4.h
index 8abee78e4d4..8a80c0c667a 100644
--- a/include/hw/pci-host/pnv_phb4.h
+++ b/include/hw/pci-host/pnv_phb4.h
@@ -13,6 +13,7 @@
 #include "hw/pci-host/pnv_phb.h"
 #include "hw/pci/pci_bus.h"
 #include "hw/ppc/pnv.h"
+#include "hw/ppc/pnv_nest_pervasive.h"
 #include "hw/ppc/xive.h"
 #include "qom/object.h"
 
@@ -174,6 +175,9 @@ struct PnvPhb4PecState {
     uint32_t index;
     uint32_t chip_id;
 
+    /* Pervasive chiplet control */
+    PnvNestChipletPervasive nest_pervasive;
+
     /* Nest registers, excuding per-stack */
 #define PHB4_PEC_NEST_REGS_COUNT    0xf
     uint64_t nest_regs[PHB4_PEC_NEST_REGS_COUNT];
@@ -196,6 +200,7 @@ struct PnvPhb4PecState {
 struct PnvPhb4PecClass {
     DeviceClass parent_class;
 
+    uint32_t (*xscom_cplt_base)(PnvPhb4PecState *pec);
     uint32_t (*xscom_nest_base)(PnvPhb4PecState *pec);
     uint32_t xscom_nest_size;
     uint32_t (*xscom_pci_base)(PnvPhb4PecState *pec);
diff --git a/include/hw/ppc/pnv_xscom.h b/include/hw/ppc/pnv_xscom.h
index 648388a5995..a927aea1c09 100644
--- a/include/hw/ppc/pnv_xscom.h
+++ b/include/hw/ppc/pnv_xscom.h
@@ -126,6 +126,8 @@ struct PnvXScomInterfaceClass {
 #define PNV9_XSCOM_PEC_PCI_BASE   0xd010800
 #define PNV9_XSCOM_PEC_PCI_SIZE   0x200
 
+#define PNV9_XSCOM_PEC_NEST_CPLT_BASE  0x0d000000
+
 /* XSCOM PCI "pass-through" window to PHB SCOM */
 #define PNV9_XSCOM_PEC_PCI_STK0   0x100
 #define PNV9_XSCOM_PEC_PCI_STK1   0x140
@@ -197,6 +199,8 @@ struct PnvXScomInterfaceClass {
 #define PNV10_XSCOM_PEC_NEST_BASE  0x3011800 /* index goes downwards ... */
 #define PNV10_XSCOM_PEC_NEST_SIZE  0x100
 
+#define PNV10_XSCOM_PEC_NEST_CPLT_BASE 0x08000000
+
 #define PNV10_XSCOM_PEC_PCI_BASE   0x8010800 /* index goes upwards ... */
 #define PNV10_XSCOM_PEC_PCI_SIZE   0x200
 
diff --git a/hw/pci-host/pnv_phb4_pec.c b/hw/pci-host/pnv_phb4_pec.c
index ce8e228f987..533c8a26131 100644
--- a/hw/pci-host/pnv_phb4_pec.c
+++ b/hw/pci-host/pnv_phb4_pec.c
@@ -197,6 +197,9 @@ static PnvPHB *pnv_pec_default_phb_realize(PnvPhb4PecState *pec,
     return phb;
 }
 
+#define   XPEC_P9_PCI_LANE_CFG                  PPC_BITMASK(10, 11)
+#define   XPEC_P10_PCI_LANE_CFG                 PPC_BITMASK(0, 1)
+
 static void pnv_pec_realize(DeviceState *dev, Error **errp)
 {
     PnvPhb4PecState *pec = PNV_PHB4_PEC(dev);
@@ -211,6 +214,43 @@ static void pnv_pec_realize(DeviceState *dev, Error **errp)
 
     pec->num_phbs = pecc->num_phbs[pec->index];
 
+    /* Pervasive chiplet */
+    object_initialize_child(OBJECT(pec), "nest-pervasive-common",
+                            &pec->nest_pervasive,
+                            TYPE_PNV_NEST_CHIPLET_PERVASIVE);
+    if (!qdev_realize(DEVICE(&pec->nest_pervasive), NULL, errp)) {
+        return;
+    }
+
+    /* Set up pervasive chiplet registers */
+    /*
+     * Most registers are not set up, this just sets the PCI CONF1 link-width
+     * field because skiboot probes it.
+     */
+    if (pecc->version == PNV_PHB4_VERSION) {
+        /*
+         * On P9, PEC2 has configurable 1/2/3-furcation).
+         * Make it trifurcated (x8, x4, x4) to match pnv_pec_num_phbs.
+         */
+        if (pec->index == 2) {
+            pec->nest_pervasive.control_regs.cplt_cfg1 =
+                    SETFIELD(XPEC_P9_PCI_LANE_CFG,
+                             pec->nest_pervasive.control_regs.cplt_cfg1,
+                             0b10);
+        }
+    } else if (pecc->version == PNV_PHB5_VERSION) {
+        /*
+         * On P10, both PECs are configurable 1/2/3-furcation).
+         * Both are trifurcated to match pnv_phb5_pec_num_stacks.
+         */
+        pec->nest_pervasive.control_regs.cplt_cfg1 =
+                SETFIELD(XPEC_P10_PCI_LANE_CFG,
+                         pec->nest_pervasive.control_regs.cplt_cfg1,
+                         0b10);
+    } else {
+        g_assert_not_reached();
+    }
+
     /* Create PHBs if running with defaults */
     if (defaults_enabled()) {
         g_assert(pec->num_phbs <= MAX_PHBS_PER_PEC);
@@ -291,9 +331,16 @@ static Property pnv_pec_properties[] = {
     DEFINE_PROP_END_OF_LIST(),
 };
 
+#define XPEC_PCI_CPLT_OFFSET                        0x1000000ULL
+
+static uint32_t pnv_pec_xscom_cplt_base(PnvPhb4PecState *pec)
+{
+    return PNV9_XSCOM_PEC_NEST_CPLT_BASE + XPEC_PCI_CPLT_OFFSET * pec->index;
+}
+
 static uint32_t pnv_pec_xscom_pci_base(PnvPhb4PecState *pec)
 {
-    return PNV9_XSCOM_PEC_PCI_BASE + 0x1000000 * pec->index;
+    return PNV9_XSCOM_PEC_PCI_BASE + XPEC_PCI_CPLT_OFFSET * pec->index;
 }
 
 static uint32_t pnv_pec_xscom_nest_base(PnvPhb4PecState *pec)
@@ -322,6 +369,7 @@ static void pnv_pec_class_init(ObjectClass *klass, void *data)
     device_class_set_props(dc, pnv_pec_properties);
     dc->user_creatable = false;
 
+    pecc->xscom_cplt_base = pnv_pec_xscom_cplt_base;
     pecc->xscom_nest_base = pnv_pec_xscom_nest_base;
     pecc->xscom_pci_base  = pnv_pec_xscom_pci_base;
     pecc->xscom_nest_size = PNV9_XSCOM_PEC_NEST_SIZE;
@@ -350,6 +398,10 @@ static const TypeInfo pnv_pec_type_info = {
 /*
  * POWER10 definitions
  */
+static uint32_t pnv_phb5_pec_xscom_cplt_base(PnvPhb4PecState *pec)
+{
+    return PNV10_XSCOM_PEC_NEST_CPLT_BASE + XPEC_PCI_CPLT_OFFSET * pec->index;
+}
 
 static uint32_t pnv_phb5_pec_xscom_pci_base(PnvPhb4PecState *pec)
 {
@@ -374,6 +426,7 @@ static void pnv_phb5_pec_class_init(ObjectClass *klass, void *data)
     static const char compat[] = "ibm,power10-pbcq";
     static const char stk_compat[] = "ibm,power10-phb-stack";
 
+    pecc->xscom_cplt_base = pnv_phb5_pec_xscom_cplt_base;
     pecc->xscom_nest_base = pnv_phb5_pec_xscom_nest_base;
     pecc->xscom_pci_base  = pnv_phb5_pec_xscom_pci_base;
     pecc->xscom_nest_size = PNV10_XSCOM_PEC_NEST_SIZE;
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 22c67e82aa7..820eabf30a8 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -1755,6 +1755,7 @@ static void pnv_chip_power9_pec_realize(PnvChip *chip, Error **errp)
     for (i = 0; i < chip->num_pecs; i++) {
         PnvPhb4PecState *pec = &chip9->pecs[i];
         PnvPhb4PecClass *pecc = PNV_PHB4_PEC_GET_CLASS(pec);
+        uint32_t pec_cplt_base;
         uint32_t pec_nest_base;
         uint32_t pec_pci_base;
 
@@ -1767,9 +1768,12 @@ static void pnv_chip_power9_pec_realize(PnvChip *chip, Error **errp)
             return;
         }
 
+        pec_cplt_base = pecc->xscom_cplt_base(pec);
         pec_nest_base = pecc->xscom_nest_base(pec);
         pec_pci_base = pecc->xscom_pci_base(pec);
 
+        pnv_xscom_add_subregion(chip, pec_cplt_base,
+                 &pec->nest_pervasive.xscom_ctrl_regs_mr);
         pnv_xscom_add_subregion(chip, pec_nest_base, &pec->nest_regs_mr);
         pnv_xscom_add_subregion(chip, pec_pci_base, &pec->pci_regs_mr);
     }
@@ -2030,6 +2034,7 @@ static void pnv_chip_power10_phb_realize(PnvChip *chip, Error **errp)
     for (i = 0; i < chip->num_pecs; i++) {
         PnvPhb4PecState *pec = &chip10->pecs[i];
         PnvPhb4PecClass *pecc = PNV_PHB4_PEC_GET_CLASS(pec);
+        uint32_t pec_cplt_base;
         uint32_t pec_nest_base;
         uint32_t pec_pci_base;
 
@@ -2042,9 +2047,12 @@ static void pnv_chip_power10_phb_realize(PnvChip *chip, Error **errp)
             return;
         }
 
+        pec_cplt_base = pecc->xscom_cplt_base(pec);
         pec_nest_base = pecc->xscom_nest_base(pec);
         pec_pci_base = pecc->xscom_pci_base(pec);
 
+        pnv_xscom_add_subregion(chip, pec_cplt_base,
+                 &pec->nest_pervasive.xscom_ctrl_regs_mr);
         pnv_xscom_add_subregion(chip, pec_nest_base, &pec->nest_regs_mr);
         pnv_xscom_add_subregion(chip, pec_pci_base, &pec->pci_regs_mr);
     }
