From: Nicholas Piggin <npiggin@gmail.com>
Date: Mon, 12 May 2025 03:10:22 +0000 (+1000)
Subject: ppc/xive: tctx_notify should clear the precluded interrupt
X-Git-Tag: v10.1.0-rc0~2^2~37
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=14bcc5239f4d4780ec52881779161c62c46e7243;p=thirdparty%2Fqemu.git

ppc/xive: tctx_notify should clear the precluded interrupt

If CPPR is lowered to preclude the pending interrupt, NSR should be
cleared and the qemu_irq should be lowered. This avoids some cases
of supurious interrupts.

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/20250512031100.439842-14-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 bc829bebe9..a0a60a24f5 100644
--- a/hw/intc/xive.c
+++ b/hw/intc/xive.c
@@ -110,6 +110,9 @@ void xive_tctx_notify(XiveTCTX *tctx, uint8_t ring, uint8_t group_level)
                                regs[TM_IPB], alt_regs[TM_PIPR],
                                alt_regs[TM_CPPR], alt_regs[TM_NSR]);
         qemu_irq_raise(xive_tctx_output(tctx, ring));
+    } else {
+        alt_regs[TM_NSR] = 0;
+        qemu_irq_lower(xive_tctx_output(tctx, ring));
     }
 }