[PATCH] spapr: propagate LPCR to hot-plugged CPUs

From: "Cédric Le Goater" <clg@kaod.org>
To: David Gibson <david@gibson.dropbear.id.au>,
	Greg Kurz <groug@kaod.org>, Nicholas Piggin <npiggin@gmail.com>
Cc: qemu-ppc@nongnu.org, qemu-devel@nongnu.org,
	"Cédric Le Goater" <clg@kaod.org>
Subject: [PATCH] spapr: propagate LPCR to hot-plugged CPUs
Date: Mon, 24 May 2021 13:41:32 +0200	[thread overview]
Message-ID: <20210524114132.572659-1-clg@kaod.org> (raw)

Distros have started using the 'scv' instructions (glibc 2.33) which
relies on the LPCR AIL bits. Unfortunately, the LPCR of hot-plugged
CPUs is not synchronized with the rest of machine and it breaks the
guest OS.

Fix that by using the first CPU to set the LPCR value of all hot-plugged
CPUs.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 hw/ppc/spapr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index c23bcc449071..e463c2570c7a 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3890,6 +3890,8 @@ static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev)
         for (i = 0; i < cc->nr_threads; i++) {
             ppc_set_compat(core->threads[i], POWERPC_CPU(first_cpu)->compat_pvr,
                            &error_abort);
+            ppc_store_lpcr(core->threads[i],
+                           POWERPC_CPU(first_cpu)->env.spr[SPR_LPCR]);
         }
     }
 
-- 
2.31.1


