All of lore.kernel.org
 help / color / mirror / Atom feed
* Patch "x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend" has been added to the 4.4-stable tree
@ 2018-03-06 18:50 gregkh
  2018-03-06 21:01 ` Greg KH
  0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2018-03-06 18:50 UTC (permalink / raw)
  To: jgross, gregkh, jbeulich, tglx; +Cc: stable, stable-commits


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

    x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend

to the 4.4-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-zero-msr_ia32_spec_ctrl-before-suspend.patch
and it can be found in the queue-4.4 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 71c208dd54ab971036d83ff6d9837bae4976e623 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@suse.com>
Date: Mon, 26 Feb 2018 15:08:18 +0100
Subject: x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend

From: Juergen Gross <jgross@suse.com>

commit 71c208dd54ab971036d83ff6d9837bae4976e623 upstream.

Older Xen versions (4.5 and before) might have problems migrating pv
guests with MSR_IA32_SPEC_CTRL having a non-zero value. So before
suspending zero that MSR and restore it after being resumed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: https://lkml.kernel.org/r/20180226140818.4849-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/xen/suspend.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

--- a/arch/x86/xen/suspend.c
+++ b/arch/x86/xen/suspend.c
@@ -1,11 +1,14 @@
 #include <linux/types.h>
 #include <linux/tick.h>
+#include <linux/percpu-defs.h>
 
 #include <xen/xen.h>
 #include <xen/interface/xen.h>
 #include <xen/grant_table.h>
 #include <xen/events.h>
 
+#include <asm/cpufeatures.h>
+#include <asm/msr-index.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/page.h>
 #include <asm/fixmap.h>
@@ -68,6 +71,8 @@ static void xen_pv_post_suspend(int susp
 	xen_mm_unpin_all();
 }
 
+static DEFINE_PER_CPU(u64, spec_ctrl);
+
 void xen_arch_pre_suspend(void)
 {
 	if (xen_pv_domain())
@@ -84,6 +89,9 @@ void xen_arch_post_suspend(int cancelled
 
 static void xen_vcpu_notify_restore(void *data)
 {
+	if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL))
+		wrmsrl(MSR_IA32_SPEC_CTRL, this_cpu_read(spec_ctrl));
+
 	/* Boot processor notified via generic timekeeping_resume() */
 	if (smp_processor_id() == 0)
 		return;
@@ -93,7 +101,15 @@ static void xen_vcpu_notify_restore(void
 
 static void xen_vcpu_notify_suspend(void *data)
 {
+	u64 tmp;
+
 	tick_suspend_local();
+
+	if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) {
+		rdmsrl(MSR_IA32_SPEC_CTRL, tmp);
+		this_cpu_write(spec_ctrl, tmp);
+		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+	}
 }
 
 void xen_arch_resume(void)


Patches currently in stable-queue which might be from jgross@suse.com are

queue-4.4/x86-xen-zero-msr_ia32_spec_ctrl-before-suspend.patch

^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH 4.4.y 040/101] x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
@ 2018-07-14  9:31 Srivatsa S. Bhat
  2018-07-23  9:22 ` Patch "x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend" has been added to the 4.4-stable tree gregkh
  0 siblings, 1 reply; 3+ messages in thread
From: Srivatsa S. Bhat @ 2018-07-14  9:31 UTC (permalink / raw)
  To: gregkh, stable
  Cc: Juergen Gross, Thomas Gleixner, Jan Beulich, xen-devel,
	boris.ostrovsky, Matt Helsley (VMware), Alexey Makhalov, Bo Gan,
	matt.helsley, rostedt, amakhalov, ganb, srivatsa, srivatsab

From: Juergen Gross <jgross@suse.com>

commit 71c208dd54ab971036d83ff6d9837bae4976e623 upstream.

Older Xen versions (4.5 and before) might have problems migrating pv
guests with MSR_IA32_SPEC_CTRL having a non-zero value. So before
suspending zero that MSR and restore it after being resumed.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: https://lkml.kernel.org/r/20180226140818.4849-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
---

 arch/x86/xen/suspend.c |   16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c
index 7f664c4..4ecd0de 100644
--- a/arch/x86/xen/suspend.c
+++ b/arch/x86/xen/suspend.c
@@ -1,11 +1,14 @@
 #include <linux/types.h>
 #include <linux/tick.h>
+#include <linux/percpu-defs.h>
 
 #include <xen/xen.h>
 #include <xen/interface/xen.h>
 #include <xen/grant_table.h>
 #include <xen/events.h>
 
+#include <asm/cpufeatures.h>
+#include <asm/msr-index.h>
 #include <asm/xen/hypercall.h>
 #include <asm/xen/page.h>
 #include <asm/fixmap.h>
@@ -68,6 +71,8 @@ static void xen_pv_post_suspend(int suspend_cancelled)
 	xen_mm_unpin_all();
 }
 
+static DEFINE_PER_CPU(u64, spec_ctrl);
+
 void xen_arch_pre_suspend(void)
 {
 	if (xen_pv_domain())
@@ -84,6 +89,9 @@ void xen_arch_post_suspend(int cancelled)
 
 static void xen_vcpu_notify_restore(void *data)
 {
+	if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL))
+		wrmsrl(MSR_IA32_SPEC_CTRL, this_cpu_read(spec_ctrl));
+
 	/* Boot processor notified via generic timekeeping_resume() */
 	if (smp_processor_id() == 0)
 		return;
@@ -93,7 +101,15 @@ static void xen_vcpu_notify_restore(void *data)
 
 static void xen_vcpu_notify_suspend(void *data)
 {
+	u64 tmp;
+
 	tick_suspend_local();
+
+	if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) {
+		rdmsrl(MSR_IA32_SPEC_CTRL, tmp);
+		this_cpu_write(spec_ctrl, tmp);
+		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+	}
 }
 
 void xen_arch_resume(void)

^ permalink raw reply related	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-07-23  9:26 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2018-03-06 18:50 Patch "x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend" has been added to the 4.4-stable tree gregkh
2018-03-06 21:01 ` Greg KH
  -- strict thread matches above, loose matches on Subject: below --
2018-07-14  9:31 [PATCH 4.4.y 040/101] x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend Srivatsa S. Bhat
2018-07-23  9:22 ` Patch "x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend" has been added to the 4.4-stable tree gregkh

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.