[SRU][Bionic][PATCH 1/1] x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths

Joseph Salisbury joseph.salisbury at canonical.com
Tue Aug 14 20:14:09 UTC 2018

From: Juergen Gross <jgross at suse.com>

BugLink: https://bugs.launchpad.net/bugs/1777338


  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 at amd.com>
Tested-by: Brian Woods <brian.woods at amd.com>
Signed-off-by: Juergen Gross <jgross at suse.com>
Cc: <stable at vger.kernel.org>
Cc: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: boris.ostrovsky at oracle.com
Cc: xen-devel at lists.xenproject.org
Fixes: 1f50ddb4f4189243c05926b842dc1a0332195f31 ("x86/speculation: Handle HT correctly on AMD")
Link: https://lore.kernel.org/lkml/20180621084331.21228-1-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo at kernel.org>
(cherry picked from commit 74899d92e66663dc7671a8017b3146dcd4735f3b)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
 arch/x86/xen/smp_pv.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index c0c756c..db6d90e 100644
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -32,6 +32,7 @@
 #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>
@@ -70,6 +71,8 @@ static void cpu_bringup(void)
 	cpu_data(cpu).x86_max_cores = 1;
+	speculative_store_bypass_ht_init();
@@ -250,6 +253,8 @@ static void __init xen_pv_smp_prepare_cpus(unsigned int max_cpus)
+	speculative_store_bypass_ht_init();
 	if (xen_smp_intr_init(0) || xen_smp_intr_init_pv(0))

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