x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths

BugLink: https://bugs.launchpad.net/bugs/1791080

commit 74899d92 upstream.

Commit:

  1f50ddb4 ("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@amd.com>
Tested-by: Brian Woods <brian.woods@amd.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: <stable@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: xen-devel@lists.xenproject.org
Fixes: 1f50ddb4 ("x86/speculation: Handle HT correctly on AMD")
Link: https://lore.kernel.org/lkml/20180621084331.21228-1-jgross@suse.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

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);
@@ -357,6 +360,8 @@ 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))