[PATCH 3.16 050/131] x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths

[Ben Hutchings]

3.16.59-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Juergen Gross <jgross@xxxxxxxx>

commit 74899d92e66663dc7671a8017b3146dcd4735f3b upstream.

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: 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>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/x86/xen/smp_pv.c | 5 +++++
 1 file changed, 5 insertions(+)

--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -27,6 +27,7 @@
 #include <xen/interface/xen.h>
 #include <xen/interface/vcpu.h>
 
+#include <asm/spec-ctrl.h>
 #include <asm/xen/interface.h>
 #include <asm/xen/hypercall.h>
 
@@ -83,6 +84,8 @@ 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);
@@ -334,6 +337,8 @@ static void __init xen_smp_prepare_cpus(
 	}
 	set_cpu_sibling_map(0);
 
+	speculative_store_bypass_ht_init();
+
 	if (xen_smp_intr_init(0))
 		BUG();