From: Glenn Miles <milesg@linux.ibm.com>

According to the XIVE spec, updating the CPPR should also update the
PIPR. The final value of the PIPR depends on other factors, but it
should never be set to a value that is above the CPPR.

Also added support for redistributing an active group interrupt when it
is precluded as a result of changing the CPPR value.

Signed-off-by: Glenn Miles <milesg@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Michael Kowal <kowal@linux.ibm.com>
Reviewed-by: Caleb Schlossin <calebs@linux.ibm.com>
Tested-by: Gautam Menghani <gautam@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20250512031100.439842-11-npiggin@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
(cherry picked from commit d4720a7faf4bb415f3fe7f10e5c888212b81316a)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index 2b4d0f51be..1971c05fa1 100644
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -995,7 +995,9 @@ static void xive2_tctx_set_cppr(XiveTCTX *tctx, uint8_t ring, uint8_t cppr)
             }
         }
     }
-    regs[TM_PIPR] = pipr_min;
+
+    /* PIPR should not be set to a value greater than CPPR */
+    regs[TM_PIPR] = (pipr_min > cppr) ? cppr : pipr_min;
 
     rc = xive2_tctx_get_nvp_indexes(tctx, ring_min, &nvp_blk, &nvp_idx);
     if (rc) {
-- 
2.47.2