4.14-stable patches

added patches:
	kvm-x86-remove-apic-timer-periodic-oneshot-spikes.patch

diff --git a/queue-4.14/kvm-x86-remove-apic-timer-periodic-oneshot-spikes.patch b/queue-4.14/kvm-x86-remove-apic-timer-periodic-oneshot-spikes.patch
new file mode 100644 (file)
index 0000000..f691df6
--- /dev/null
+++ b/queue-4.14/kvm-x86-remove-apic-timer-periodic-oneshot-spikes.patch
@@ -0,0 +1,107 @@
+From ecf08dad723d3e000aecff6c396f54772d124733 Mon Sep 17 00:00:00 2001
+From: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
+Date: Sun, 29 Apr 2018 22:05:58 +0000
+Subject: KVM: x86: remove APIC Timer periodic/oneshot spikes
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+From: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
+
+commit ecf08dad723d3e000aecff6c396f54772d124733 upstream.
+
+Since the commit "8003c9ae204e: add APIC Timer periodic/oneshot mode VMX
+preemption timer support", a Windows 10 guest has some erratic timer
+spikes.
+
+Here the results on a 150000 times 1ms timer without any load:
+         Before 8003c9ae204e | After 8003c9ae204e
+Max           1834us          |  86000us
+Mean          1100us          |   1021us
+Deviation       59us          |    149us
+Here the results on a 150000 times 1ms timer with a cpu-z stress test:
+         Before 8003c9ae204e | After 8003c9ae204e
+Max          32000us          | 140000us
+Mean          1006us          |   1997us
+Deviation      140us          |  11095us
+
+The root cause of the problem is starting hrtimer with an expiry time
+already in the past can take more than 20 milliseconds to trigger the
+timer function.  It can be solved by forward such past timers
+immediately, rather than submitting them to hrtimer_start().
+In case the timer is periodic, update the target expiration and call
+hrtimer_start with it.
+
+v2: Check if the tsc deadline is already expired. Thank you Mika.
+v3: Execute the past timers immediately rather than submitting them to
+hrtimer_start().
+v4: Rearm the periodic timer with advance_periodic_target_expiration() a
+simpler version of set_target_expiration(). Thank you Paolo.
+
+Cc: Mika Penttilä <mika.penttila@nextfour.com>
+Cc: Wanpeng Li <kernellwp@gmail.com>
+Cc: Paolo Bonzini <pbonzini@redhat.com>
+Cc: stable@vger.kernel.org
+Signed-off-by: Anthoine Bourgeois <anthoine.bourgeois@blade-group.com>
+8003c9ae204e ("KVM: LAPIC: add APIC Timer periodic/oneshot mode VMX preemption timer support")
+Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ arch/x86/kvm/lapic.c |   37 ++++++++++++++++++++-----------------
+ 1 file changed, 20 insertions(+), 17 deletions(-)
+
+--- a/arch/x86/kvm/lapic.c
++++ b/arch/x86/kvm/lapic.c
+@@ -1418,23 +1418,6 @@ static void start_sw_tscdeadline(struct
+       local_irq_restore(flags);
+ }
+ 
+-static void start_sw_period(struct kvm_lapic *apic)
+-{
+-      if (!apic->lapic_timer.period)
+-              return;
+-
+-      if (apic_lvtt_oneshot(apic) &&
+-          ktime_after(ktime_get(),
+-                      apic->lapic_timer.target_expiration)) {
+-              apic_timer_expired(apic);
+-              return;
+-      }
+-
+-      hrtimer_start(&apic->lapic_timer.timer,
+-              apic->lapic_timer.target_expiration,
+-              HRTIMER_MODE_ABS_PINNED);
+-}
+-
+ static bool set_target_expiration(struct kvm_lapic *apic)
+ {
+       ktime_t now;
+@@ -1491,6 +1474,26 @@ static void advance_periodic_target_expi
+                               apic->lapic_timer.period);
+ }
+ 
++static void start_sw_period(struct kvm_lapic *apic)
++{
++      if (!apic->lapic_timer.period)
++              return;
++
++      if (ktime_after(ktime_get(),
++                      apic->lapic_timer.target_expiration)) {
++              apic_timer_expired(apic);
++
++              if (apic_lvtt_oneshot(apic))
++                      return;
++
++              advance_periodic_target_expiration(apic);
++      }
++
++      hrtimer_start(&apic->lapic_timer.timer,
++              apic->lapic_timer.target_expiration,
++              HRTIMER_MODE_ABS_PINNED);
++}
++
+ bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu)
+ {
+       if (!lapic_in_kernel(vcpu))

diff --git a/queue-4.14/series b/queue-4.14/series
index 0fa13bdda86bf0b133130e3587221688fc6d1c37..67e58621019fe80f377a46d6400248d9ca31e1e4 100644 (file)
--- a/queue-4.14/series
+++ b/queue-4.14/series
@@ -59,3 +59,4 @@ perf-x86-msr-fix-possible-spectre-v1-indexing-in-the-msr-driver.patch
 perf-core-fix-possible-spectre-v1-indexing-for-aux_pages.patch
 perf-x86-fix-possible-spectre-v1-indexing-for-x86_pmu-event_map.patch
 kvm-ppc-book3s-hv-fix-handling-of-large-pages-in-radix-page-fault-handler.patch
+kvm-x86-remove-apic-timer-periodic-oneshot-spikes.patch