diff --git a/include/hw/ppc/xive.h b/include/hw/ppc/xive.h
index f443a39cf1..8317fde0db 100644
--- a/include/hw/ppc/xive.h
+++ b/include/hw/ppc/xive.h
@@ -438,13 +438,13 @@ struct XivePresenterClass {
     InterfaceClass parent;
     int (*match_nvt)(XivePresenter *xptr, uint8_t format,
                      uint8_t nvt_blk, uint32_t nvt_idx,
-                     bool cam_ignore, uint8_t priority,
+                     bool crowd, bool cam_ignore, uint8_t priority,
                      uint32_t logic_serv, XiveTCTXMatch *match);
     bool (*in_kernel)(const XivePresenter *xptr);
     uint32_t (*get_config)(XivePresenter *xptr);
     int (*broadcast)(XivePresenter *xptr,
                      uint8_t nvt_blk, uint32_t nvt_idx,
-                     uint8_t priority);
+                     bool crowd, bool cam_ignore, uint8_t priority);
 };
 
 int xive_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
@@ -453,7 +453,7 @@ int xive_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
                               bool cam_ignore, uint32_t logic_serv);
 bool xive_presenter_notify(XiveFabric *xfb, uint8_t format,
                            uint8_t nvt_blk, uint32_t nvt_idx,
-                           bool cam_ignore, uint8_t priority,
+                           bool crowd, bool cam_ignore, uint8_t priority,
                            uint32_t logic_serv, bool *precluded);
 
 uint32_t xive_get_vpgroup_size(uint32_t nvp_index);
@@ -473,10 +473,10 @@ struct XiveFabricClass {
     InterfaceClass parent;
     int (*match_nvt)(XiveFabric *xfb, uint8_t format,
                      uint8_t nvt_blk, uint32_t nvt_idx,
-                     bool cam_ignore, uint8_t priority,
+                     bool crowd, bool cam_ignore, uint8_t priority,
                      uint32_t logic_serv, XiveTCTXMatch *match);
     int (*broadcast)(XiveFabric *xfb, uint8_t nvt_blk, uint32_t nvt_idx,
-                     uint8_t priority);
+                     bool crowd, bool cam_ignore, uint8_t priority);
 };
 
 /*
diff --git a/include/hw/ppc/xive2.h b/include/hw/ppc/xive2.h
index c07e23e1d3..8cdf819174 100644
--- a/include/hw/ppc/xive2.h
+++ b/include/hw/ppc/xive2.h
@@ -88,7 +88,8 @@ void xive2_router_notify(XiveNotifier *xn, uint32_t lisn, bool pq_checked);
 int xive2_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
                                uint8_t format,
                                uint8_t nvt_blk, uint32_t nvt_idx,
-                               bool cam_ignore, uint32_t logic_serv);
+                               bool crowd, bool cam_ignore,
+                               uint32_t logic_serv);
 
 uint64_t xive2_presenter_nvp_backlog_op(XivePresenter *xptr,
                                         uint8_t blk, uint32_t idx,
diff --git a/hw/intc/pnv_xive.c b/hw/intc/pnv_xive.c
index 5bacbce6a4..d4796ab5a6 100644
--- a/hw/intc/pnv_xive.c
+++ b/hw/intc/pnv_xive.c
@@ -1,10 +1,9 @@
 /*
  * QEMU PowerPC XIVE interrupt controller model
  *
- * Copyright (c) 2017-2019, IBM Corporation.
+ * Copyright (c) 2017-2024, IBM Corporation.
  *
- * This code is licensed under the GPL version 2 or later. See the
- * COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "qemu/osdep.h"
@@ -473,7 +472,7 @@ static bool pnv_xive_is_cpu_enabled(PnvXive *xive, PowerPCCPU *cpu)
 
 static int pnv_xive_match_nvt(XivePresenter *xptr, uint8_t format,
                               uint8_t nvt_blk, uint32_t nvt_idx,
-                              bool cam_ignore, uint8_t priority,
+                              bool crowd, bool cam_ignore, uint8_t priority,
                               uint32_t logic_serv, XiveTCTXMatch *match)
 {
     PnvXive *xive = PNV_XIVE(xptr);
@@ -500,7 +499,8 @@ static int pnv_xive_match_nvt(XivePresenter *xptr, uint8_t format,
              * Check the thread context CAM lines and record matches.
              */
             ring = xive_presenter_tctx_match(xptr, tctx, format, nvt_blk,
-                                             nvt_idx, cam_ignore, logic_serv);
+                                             nvt_idx, cam_ignore,
+                                             logic_serv);
             /*
              * Save the context and follow on to catch duplicates, that we
              * don't support yet.
diff --git a/hw/intc/pnv_xive2.c b/hw/intc/pnv_xive2.c
index 54abfe3947..91f3514f93 100644
--- a/hw/intc/pnv_xive2.c
+++ b/hw/intc/pnv_xive2.c
@@ -624,7 +624,7 @@ static bool pnv_xive2_is_cpu_enabled(PnvXive2 *xive, PowerPCCPU *cpu)
 
 static int pnv_xive2_match_nvt(XivePresenter *xptr, uint8_t format,
                                uint8_t nvt_blk, uint32_t nvt_idx,
-                               bool cam_ignore, uint8_t priority,
+                               bool crowd, bool cam_ignore, uint8_t priority,
                                uint32_t logic_serv, XiveTCTXMatch *match)
 {
     PnvXive2 *xive = PNV_XIVE2(xptr);
@@ -655,8 +655,8 @@ static int pnv_xive2_match_nvt(XivePresenter *xptr, uint8_t format,
                                                  logic_serv);
             } else {
                 ring = xive2_presenter_tctx_match(xptr, tctx, format, nvt_blk,
-                                                   nvt_idx, cam_ignore,
-                                                   logic_serv);
+                                                  nvt_idx, crowd, cam_ignore,
+                                                  logic_serv);
             }
 
             if (ring != -1) {
@@ -707,7 +707,7 @@ static uint32_t pnv_xive2_presenter_get_config(XivePresenter *xptr)
 
 static int pnv_xive2_broadcast(XivePresenter *xptr,
                                uint8_t nvt_blk, uint32_t nvt_idx,
-                               uint8_t priority)
+                               bool crowd, bool ignore, uint8_t priority)
 {
     PnvXive2 *xive = PNV_XIVE2(xptr);
     PnvChip *chip = xive->chip;
@@ -732,10 +732,10 @@ static int pnv_xive2_broadcast(XivePresenter *xptr,
 
             if (gen1_tima_os) {
                 ring = xive_presenter_tctx_match(xptr, tctx, 0, nvt_blk,
-                                                 nvt_idx, true, 0);
+                                                 nvt_idx, ignore, 0);
             } else {
                 ring = xive2_presenter_tctx_match(xptr, tctx, 0, nvt_blk,
-                                                  nvt_idx, true, 0);
+                                                  nvt_idx, crowd, ignore, 0);
             }
 
             if (ring != -1) {
diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
index 283a6b8fd2..0477fdd594 100644
--- a/hw/intc/spapr_xive.c
+++ b/hw/intc/spapr_xive.c
@@ -1,10 +1,9 @@
 /*
  * QEMU PowerPC sPAPR XIVE interrupt controller model
  *
- * Copyright (c) 2017-2018, IBM Corporation.
+ * Copyright (c) 2017-2024, IBM Corporation.
  *
- * This code is licensed under the GPL version 2 or later. See the
- * COPYING file in the top-level directory.
+ * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "qemu/osdep.h"
@@ -431,7 +430,8 @@ static int spapr_xive_write_nvt(XiveRouter *xrtr, uint8_t nvt_blk,
 
 static int spapr_xive_match_nvt(XivePresenter *xptr, uint8_t format,
                                 uint8_t nvt_blk, uint32_t nvt_idx,
-                                bool cam_ignore, uint8_t priority,
+                                bool crowd, bool cam_ignore,
+                                uint8_t priority,
                                 uint32_t logic_serv, XiveTCTXMatch *match)
 {
     CPUState *cs;
diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 308de5aefc..97d1c42bb2 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -1667,10 +1667,37 @@ uint32_t xive_get_vpgroup_size(uint32_t nvp_index)
     return 1 << (ctz32(~nvp_index) + 1);
 }
 
-static uint8_t xive_get_group_level(uint32_t nvp_index)
+static uint8_t xive_get_group_level(bool crowd, bool ignore,
+                                    uint32_t nvp_blk, uint32_t nvp_index)
 {
-    /* FIXME add crowd encoding */
-    return ctz32(~nvp_index) + 1;
+    uint8_t level = 0;
+
+    if (crowd) {
+        /* crowd level is bit position of first 0 from the right in nvp_blk */
+        level = ctz32(~nvp_blk) + 1;
+
+        /*
+         * Supported crowd sizes are 2^1, 2^2, and 2^4. 2^3 is not supported.
+         * HW will encode level 4 as the value 3.  See xive2_pgofnext().
+         */
+        switch (level) {
+        case 1:
+        case 2:
+            break;
+        case 4:
+            level = 3;
+            break;
+        default:
+            g_assert_not_reached();
+        }
+
+        /* Crowd level bits reside in upper 2 bits of the 6 bit group level */
+        level <<= 4;
+    }
+    if (ignore) {
+        level |= (ctz32(~nvp_index) + 1) & 0b1111;
+    }
+    return level;
 }
 
 /*
@@ -1742,7 +1769,7 @@ int xive_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
  */
 bool xive_presenter_notify(XiveFabric *xfb, uint8_t format,
                            uint8_t nvt_blk, uint32_t nvt_idx,
-                           bool cam_ignore, uint8_t priority,
+                           bool crowd, bool cam_ignore, uint8_t priority,
                            uint32_t logic_serv, bool *precluded)
 {
     XiveFabricClass *xfc = XIVE_FABRIC_GET_CLASS(xfb);
@@ -1773,7 +1800,7 @@ bool xive_presenter_notify(XiveFabric *xfb, uint8_t format,
      * a new command to the presenters (the equivalent of the "assign"
      * power bus command in the documented full notify sequence.
      */
-    count = xfc->match_nvt(xfb, format, nvt_blk, nvt_idx, cam_ignore,
+    count = xfc->match_nvt(xfb, format, nvt_blk, nvt_idx, crowd, cam_ignore,
                            priority, logic_serv, &match);
     if (count < 0) {
         return false;
@@ -1781,7 +1808,7 @@ bool xive_presenter_notify(XiveFabric *xfb, uint8_t format,
 
     /* handle CPU exception delivery */
     if (count) {
-        group_level = cam_ignore ? xive_get_group_level(nvt_idx) : 0;
+        group_level = xive_get_group_level(crowd, cam_ignore, nvt_blk, nvt_idx);
         trace_xive_presenter_notify(nvt_blk, nvt_idx, match.ring, group_level);
         xive_tctx_pipr_update(match.tctx, match.ring, priority, group_level);
     } else {
@@ -1906,6 +1933,7 @@ void xive_router_end_notify(XiveRouter *xrtr, XiveEAS *eas)
     }
 
     found = xive_presenter_notify(xrtr->xfb, format, nvt_blk, nvt_idx,
+                          false /* crowd */,
                           xive_get_field32(END_W7_F0_IGNORE, end.w7),
                           priority,
                           xive_get_field32(END_W7_F1_LOG_SERVER_ID, end.w7),
diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index f4621bdd02..20d63e8f6e 100644
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -1120,13 +1120,42 @@ static bool xive2_vp_match_mask(uint32_t cam1, uint32_t cam2,
     return (cam1 & vp_mask) == (cam2 & vp_mask);
 }
 
+static uint8_t xive2_get_vp_block_mask(uint32_t nvt_blk, bool crowd)
+{
+    uint8_t size, block_mask = 0b1111;
+
+    /* 3 supported crowd sizes: 2, 4, 16 */
+    if (crowd) {
+        size = xive_get_vpgroup_size(nvt_blk);
+        if (size == 8) {
+            qemu_log_mask(LOG_GUEST_ERROR, "XIVE: Invalid crowd size of 8n");
+            return block_mask;
+        }
+        block_mask = ~(size - 1);
+        block_mask &= 0b1111;
+    }
+    return block_mask;
+}
+
+static uint32_t xive2_get_vp_index_mask(uint32_t nvt_index, bool cam_ignore)
+{
+    uint32_t index_mask = 0xFFFFFF; /* 24 bits */
+
+    if (cam_ignore) {
+        index_mask = ~(xive_get_vpgroup_size(nvt_index) - 1);
+        index_mask &= 0xFFFFFF;
+    }
+    return index_mask;
+}
+
 /*
  * The thread context register words are in big-endian format.
  */
 int xive2_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
                                uint8_t format,
                                uint8_t nvt_blk, uint32_t nvt_idx,
-                               bool cam_ignore, uint32_t logic_serv)
+                               bool crowd, bool cam_ignore,
+                               uint32_t logic_serv)
 {
     uint32_t cam =   xive2_nvp_cam_line(nvt_blk, nvt_idx);
     uint32_t qw3w2 = xive_tctx_word2(&tctx->regs[TM_QW3_HV_PHYS]);
@@ -1134,7 +1163,8 @@ int xive2_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
     uint32_t qw1w2 = xive_tctx_word2(&tctx->regs[TM_QW1_OS]);
     uint32_t qw0w2 = xive_tctx_word2(&tctx->regs[TM_QW0_USER]);
 
-    uint32_t vp_mask = 0xFFFFFFFF;
+    uint32_t index_mask, vp_mask;
+    uint8_t block_mask;
 
     if (format == 0) {
         /*
@@ -1142,9 +1172,9 @@ int xive2_presenter_tctx_match(XivePresenter *xptr, XiveTCTX *tctx,
          * i=1: VP-group notification (bits ignored at the end of the
          *      NVT identifier)
          */
-        if (cam_ignore) {
-            vp_mask = ~(xive_get_vpgroup_size(nvt_idx) - 1);
-        }
+        block_mask = xive2_get_vp_block_mask(nvt_blk, crowd);
+        index_mask = xive2_get_vp_index_mask(nvt_idx, cam_ignore);
+        vp_mask = xive2_nvp_cam_line(block_mask, index_mask);
 
         /* For VP-group notifications, threads with LGS=0 are excluded */
 
@@ -1277,6 +1307,12 @@ static void xive2_router_end_notify(Xive2Router *xrtr, uint8_t end_blk,
         return;
     }
 
+    if (xive2_end_is_crowd(&end) & !xive2_end_is_ignore(&end)) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "XIVE: invalid END, 'crowd' bit requires 'ignore' bit\n");
+        return;
+    }
+
     if (xive2_end_is_enqueue(&end)) {
         xive2_end_enqueue(&end, end_data);
         /* Enqueuing event data modifies the EQ toggle and index */
@@ -1338,7 +1374,7 @@ static void xive2_router_end_notify(Xive2Router *xrtr, uint8_t end_blk,
     }
 
     found = xive_presenter_notify(xrtr->xfb, format, nvp_blk, nvp_idx,
-                          xive2_end_is_ignore(&end),
+                          xive2_end_is_crowd(&end), xive2_end_is_ignore(&end),
                           priority,
                           xive_get_field32(END2_W7_F1_LOG_SERVER_ID, end.w7),
                           &precluded);
@@ -1375,17 +1411,24 @@ static void xive2_router_end_notify(Xive2Router *xrtr, uint8_t end_blk,
             nvp.w2 = xive_set_field32(NVP2_W2_IPB, nvp.w2, ipb);
             xive2_router_write_nvp(xrtr, nvp_blk, nvp_idx, &nvp, 2);
         } else {
-            Xive2Nvgc nvg;
+            Xive2Nvgc nvgc;
             uint32_t backlog;
+            bool crowd;
 
-            /* For groups, the per-priority backlog counters are in the NVG */
-            if (xive2_router_get_nvgc(xrtr, false, nvp_blk, nvp_idx, &nvg)) {
-                qemu_log_mask(LOG_GUEST_ERROR, "XIVE: no NVG %x/%x\n",
-                              nvp_blk, nvp_idx);
+            crowd = xive2_end_is_crowd(&end);
+
+            /*
+             * For groups and crowds, the per-priority backlog
+             * counters are stored in the NVG/NVC structures
+             */
+            if (xive2_router_get_nvgc(xrtr, crowd,
+                                      nvp_blk, nvp_idx, &nvgc)) {
+                qemu_log_mask(LOG_GUEST_ERROR, "XIVE: no %s %x/%x\n",
+                              crowd ? "NVC" : "NVG", nvp_blk, nvp_idx);
                 return;
             }
 
-            if (!xive2_nvgc_is_valid(&nvg)) {
+            if (!xive2_nvgc_is_valid(&nvgc)) {
                 qemu_log_mask(LOG_GUEST_ERROR, "XIVE: NVG %x/%x is invalid\n",
                               nvp_blk, nvp_idx);
                 return;
@@ -1398,13 +1441,16 @@ static void xive2_router_end_notify(Xive2Router *xrtr, uint8_t end_blk,
              * set the LSMFB field of the TIMA of relevant threads so
              * that they know an interrupt is pending.
              */
-            backlog = xive2_nvgc_get_backlog(&nvg, priority) + 1;
-            xive2_nvgc_set_backlog(&nvg, priority, backlog);
-            xive2_router_write_nvgc(xrtr, false, nvp_blk, nvp_idx, &nvg);
+            backlog = xive2_nvgc_get_backlog(&nvgc, priority) + 1;
+            xive2_nvgc_set_backlog(&nvgc, priority, backlog);
+            xive2_router_write_nvgc(xrtr, crowd, nvp_blk, nvp_idx, &nvgc);
 
             if (precluded && backlog == 1) {
                 XiveFabricClass *xfc = XIVE_FABRIC_GET_CLASS(xrtr->xfb);
-                xfc->broadcast(xrtr->xfb, nvp_blk, nvp_idx, priority);
+                xfc->broadcast(xrtr->xfb, nvp_blk, nvp_idx,
+                               xive2_end_is_crowd(&end),
+                               xive2_end_is_ignore(&end),
+                               priority);
 
                 if (!xive2_end_is_precluded_escalation(&end)) {
                     /*
diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
index 7c11143749..6681648ed6 100644
--- a/hw/ppc/pnv.c
+++ b/hw/ppc/pnv.c
@@ -2585,7 +2585,7 @@ static void pnv_pic_print_info(InterruptStatsProvider *obj, GString *buf)
 
 static int pnv_match_nvt(XiveFabric *xfb, uint8_t format,
                          uint8_t nvt_blk, uint32_t nvt_idx,
-                         bool cam_ignore, uint8_t priority,
+                         bool crowd, bool cam_ignore, uint8_t priority,
                          uint32_t logic_serv,
                          XiveTCTXMatch *match)
 {
@@ -2599,8 +2599,8 @@ static int pnv_match_nvt(XiveFabric *xfb, uint8_t format,
         XivePresenterClass *xpc = XIVE_PRESENTER_GET_CLASS(xptr);
         int count;
 
-        count = xpc->match_nvt(xptr, format, nvt_blk, nvt_idx, cam_ignore,
-                               priority, logic_serv, match);
+        count = xpc->match_nvt(xptr, format, nvt_blk, nvt_idx, crowd,
+                               cam_ignore, priority, logic_serv, match);
 
         if (count < 0) {
             return count;
@@ -2614,7 +2614,7 @@ static int pnv_match_nvt(XiveFabric *xfb, uint8_t format,
 
 static int pnv10_xive_match_nvt(XiveFabric *xfb, uint8_t format,
                                 uint8_t nvt_blk, uint32_t nvt_idx,
-                                bool cam_ignore, uint8_t priority,
+                                bool crowd, bool cam_ignore, uint8_t priority,
                                 uint32_t logic_serv,
                                 XiveTCTXMatch *match)
 {
@@ -2628,8 +2628,8 @@ static int pnv10_xive_match_nvt(XiveFabric *xfb, uint8_t format,
         XivePresenterClass *xpc = XIVE_PRESENTER_GET_CLASS(xptr);
         int count;
 
-        count = xpc->match_nvt(xptr, format, nvt_blk, nvt_idx, cam_ignore,
-                               priority, logic_serv, match);
+        count = xpc->match_nvt(xptr, format, nvt_blk, nvt_idx, crowd,
+                               cam_ignore, priority, logic_serv, match);
 
         if (count < 0) {
             return count;
@@ -2643,6 +2643,7 @@ static int pnv10_xive_match_nvt(XiveFabric *xfb, uint8_t format,
 
 static int pnv10_xive_broadcast(XiveFabric *xfb,
                                 uint8_t nvt_blk, uint32_t nvt_idx,
+                                bool crowd, bool cam_ignore,
                                 uint8_t priority)
 {
     PnvMachineState *pnv = PNV_MACHINE(xfb);
@@ -2653,7 +2654,7 @@ static int pnv10_xive_broadcast(XiveFabric *xfb,
         XivePresenter *xptr = XIVE_PRESENTER(&chip10->xive);
         XivePresenterClass *xpc = XIVE_PRESENTER_GET_CLASS(xptr);
 
-        xpc->broadcast(xptr, nvt_blk, nvt_idx, priority);
+        xpc->broadcast(xptr, nvt_blk, nvt_idx, crowd, cam_ignore, priority);
     }
     return 0;
 }
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 0d4efaa0c0..7a922ef309 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4,6 +4,9 @@
  * Copyright (c) 2004-2007 Fabrice Bellard
  * Copyright (c) 2007 Jocelyn Mayer
  * Copyright (c) 2010 David Gibson, IBM Corporation.
+ * Copyright (c) 2010-2024, IBM Corporation..
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -4437,7 +4440,7 @@ static void spapr_pic_print_info(InterruptStatsProvider *obj, GString *buf)
  */
 static int spapr_match_nvt(XiveFabric *xfb, uint8_t format,
                            uint8_t nvt_blk, uint32_t nvt_idx,
-                           bool cam_ignore, uint8_t priority,
+                           bool crowd, bool cam_ignore, uint8_t priority,
                            uint32_t logic_serv, XiveTCTXMatch *match)
 {
     SpaprMachineState *spapr = SPAPR_MACHINE(xfb);
@@ -4445,7 +4448,7 @@ static int spapr_match_nvt(XiveFabric *xfb, uint8_t format,
     XivePresenterClass *xpc = XIVE_PRESENTER_GET_CLASS(xptr);
     int count;
 
-    count = xpc->match_nvt(xptr, format, nvt_blk, nvt_idx, cam_ignore,
+    count = xpc->match_nvt(xptr, format, nvt_blk, nvt_idx, crowd, cam_ignore,
                            priority, logic_serv, match);
     if (count < 0) {
         return count;
