Hi Greg,
please apply the attched backported patch to the 4.9 stable tree.
Juergen
>From d429761a575c3b444662ae73911c383e64248da1 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@xxxxxxxx>
Date: Thu, 5 Jul 2018 14:33:15 +0200
Subject: [PATCH] x86/xen: Add call of speculative_store_bypass_ht_init() to PV
paths
Commit:
1f50ddb4f418 ("x86/speculation: Handle HT correctly on AMD")
... added speculative_store_bypass_ht_init() to the per-CPU initialization sequence.
speculative_store_bypass_ht_init() needs to be called on each CPU for
PV guests, too.
Reported-by: Brian Woods <brian.woods@xxxxxxx>
Tested-by: Brian Woods <brian.woods@xxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: boris.ostrovsky@xxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
Fixes: 1f50ddb4f4189243c05926b842dc1a0332195f31 ("x86/speculation: Handle HT correctly on AMD")
Link: https://lore.kernel.org/lkml/20180621084331.21228-1-jgross@xxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
Backport to stable 4.9 of upstream commit: 74899d92e66663dc7671a8017b3146dcd4735f3b
---
arch/x86/xen/smp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index a11540e51f62..8eca26ef6471 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -28,6 +28,7 @@
#include <xen/interface/vcpu.h>
#include <xen/interface/xenpmu.h>
+#include <asm/spec-ctrl.h>
#include <asm/xen/interface.h>
#include <asm/xen/hypercall.h>
@@ -87,6 +88,8 @@ static void cpu_bringup(void)
cpu_data(cpu).x86_max_cores = 1;
set_cpu_sibling_map(cpu);
+ speculative_store_bypass_ht_init();
+
xen_setup_cpu_clockevents();
notify_cpu_starting(cpu);
@@ -375,6 +378,8 @@ static void __init xen_smp_prepare_cpus(unsigned int max_cpus)
}
set_cpu_sibling_map(0);
+ speculative_store_bypass_ht_init();
+
xen_pmu_init(0);
if (xen_smp_intr_init(0))
--
2.13.7
