ppc/xive2: Do not present group interrupt on OS-push if precluded by CPPR

Group interrupts should not be taken from the backlog and presented
if they are precluded by CPPR.

Fixes: 855434b3b8 ("ppc/xive2: Process group backlog when pushing an OS context")
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/20250512031100.439842-12-npiggin@gmail.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/intc/xive2.c b/hw/intc/xive2.c
index c23933f8f550500fae06768c0d3085b6e598d9b9..181d1ae5f94050f854ffcb69eacb2dca326ae825 100644 (file)
--- a/hw/intc/xive2.c
+++ b/hw/intc/xive2.c
@@ -845,7 +845,9 @@ static void xive2_tctx_need_resend(Xive2Router *xrtr, XiveTCTX *tctx,
         group_prio = xive2_presenter_backlog_scan(xptr, nvp_blk, nvp_idx,
                                                   first_group, &group_level);
         regs[TM_LSMFB] = group_prio;
-        if (regs[TM_LGS] && group_prio < backlog_prio) {
+        if (regs[TM_LGS] && group_prio < backlog_prio &&
+            group_prio < regs[TM_CPPR]) {
+
             /* VP can take a group interrupt */
             xive2_presenter_backlog_decr(xptr, nvp_blk, nvp_idx,
                                          group_prio, group_level);