Patch "x86/xen: Calculate __max_logical_packages on PV domains" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    x86/xen: Calculate __max_logical_packages on PV domains

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     x86-xen-calculate-__max_logical_packages-on-pv-domains.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 63e708f826bb21470155d37b103a75d8a9e25b18 Mon Sep 17 00:00:00 2001
From: Prarit Bhargava <prarit@redhat.com>
Date: Wed, 7 Feb 2018 18:49:23 -0500
Subject: x86/xen: Calculate __max_logical_packages on PV domains

From: Prarit Bhargava <prarit@redhat.com>

commit 63e708f826bb21470155d37b103a75d8a9e25b18 upstream.

The kernel panics on PV domains because native_smp_cpus_done() is
only called for HVM domains.

Calculate __max_logical_packages for PV domains.

Fixes: b4c0a7326f5d ("x86/smpboot: Fix __max_logical_packages estimate")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Tested-and-reported-by: Simon Gaiser <simon@invisiblethingslab.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: xen-devel@lists.xenproject.org
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/include/asm/smp.h |    1 +
 arch/x86/kernel/smpboot.c  |   10 ++++++++--
 arch/x86/xen/smp.c         |    2 ++
 3 files changed, 11 insertions(+), 2 deletions(-)

--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -129,6 +129,7 @@ static inline void arch_send_call_functi
 void cpu_disable_common(void);
 void native_smp_prepare_boot_cpu(void);
 void native_smp_prepare_cpus(unsigned int max_cpus);
+void calculate_max_logical_packages(void);
 void native_smp_cpus_done(unsigned int max_cpus);
 void common_cpu_up(unsigned int cpunum, struct task_struct *tidle);
 int native_cpu_up(unsigned int cpunum, struct task_struct *tidle);
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1282,11 +1282,10 @@ void __init native_smp_prepare_boot_cpu(
 	cpu_set_state_online(me);
 }
 
-void __init native_smp_cpus_done(unsigned int max_cpus)
+void __init calculate_max_logical_packages(void)
 {
 	int ncpus;
 
-	pr_debug("Boot done\n");
 	/*
 	 * Today neither Intel nor AMD support heterogenous systems so
 	 * extrapolate the boot cpu's data to all packages.
@@ -1294,6 +1293,13 @@ void __init native_smp_cpus_done(unsigne
 	ncpus = cpu_data(0).booted_cores * topology_max_smt_threads();
 	__max_logical_packages = DIV_ROUND_UP(nr_cpu_ids, ncpus);
 	pr_info("Max logical packages: %u\n", __max_logical_packages);
+}
+
+void __init native_smp_cpus_done(unsigned int max_cpus)
+{
+	pr_debug("Boot done\n");
+
+	calculate_max_logical_packages();
 
 	if (x86_has_numa_in_package)
 		set_sched_topology(x86_numa_in_package_topology);
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -122,6 +122,8 @@ void __init xen_smp_cpus_done(unsigned i
 
 	if (xen_hvm_domain())
 		native_smp_cpus_done(max_cpus);
+	else
+		calculate_max_logical_packages();
 
 	if (xen_have_vcpu_info_placement)
 		return;


Patches currently in stable-queue which might be from prarit@redhat.com are

queue-4.15/x86-xen-calculate-__max_logical_packages-on-pv-domains.patch