ppc/xive: Fix PHYS NSR ring matching

Test that the NSR exception bit field is equal to the pool ring value,
rather than any common bits set, which is more correct (although there
is no practical bug because the LSI NSR type is not implemented and
POOL/PHYS NSR are encoded with exclusive bits).

Fixes: 4c3ccac636 ("pnv/xive: Add special handling for pool targets")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Glenn Miles <milesg@linux.ibm.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/20250512031100.439842-7-npiggin@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/intc/xive.c b/hw/intc/xive.c
index 120376fb6b6dfb221776f58e44a6103e2db8d2b9..bc829bebe9d068bbb022fa727f1807332ff71def 100644 (file)
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -54,7 +54,8 @@ static uint64_t xive_tctx_accept(XiveTCTX *tctx, uint8_t ring)
         uint8_t *alt_regs;
 
         /* POOL interrupt uses IPB in QW2, POOL ring */
-        if ((ring == TM_QW3_HV_PHYS) && (nsr & (TM_QW3_NSR_HE_POOL << 6))) {
+        if ((ring == TM_QW3_HV_PHYS) &&
+            ((nsr & TM_QW3_NSR_HE) == (TM_QW3_NSR_HE_POOL << 6))) {
             alt_ring = TM_QW2_HV_POOL;
         } else {
             alt_ring = ring;