This is a note to let you know that I've just added the patch titled
KVM: x86: fix lapic.timer_mode on restore
to the 4.0-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:
kvm-x86-fix-lapic.timer_mode-on-restore.patch
and it can be found in the queue-4.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b6ac069532218027f2991cba01d7a72a200688b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@xxxxxxxxxx>
Date: Fri, 5 Jun 2015 20:57:41 +0200
Subject: KVM: x86: fix lapic.timer_mode on restore
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From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@xxxxxxxxxx>
commit b6ac069532218027f2991cba01d7a72a200688b0 upstream.
lapic.timer_mode was not properly initialized after migration, which
broke few useful things, like login, by making every sleep eternal.
Fix this by calling apic_update_lvtt in kvm_apic_post_state_restore.
There are other slowpaths that update lvtt, so this patch makes sure
something similar doesn't happen again by calling apic_update_lvtt
after every modification.
Fixes: f30ebc312ca9 ("KVM: x86: optimize some accesses to LVTT and SPIV")
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1064,6 +1064,17 @@ static void update_divide_count(struct k
apic->divide_count);
}
+static void apic_update_lvtt(struct kvm_lapic *apic)
+{
+ u32 timer_mode = kvm_apic_get_reg(apic, APIC_LVTT) &
+ apic->lapic_timer.timer_mode_mask;
+
+ if (apic->lapic_timer.timer_mode != timer_mode) {
+ apic->lapic_timer.timer_mode = timer_mode;
+ hrtimer_cancel(&apic->lapic_timer.timer);
+ }
+}
+
static void apic_timer_expired(struct kvm_lapic *apic)
{
struct kvm_vcpu *vcpu = apic->vcpu;
@@ -1272,6 +1283,7 @@ static int apic_reg_write(struct kvm_lap
apic_set_reg(apic, APIC_LVTT + 0x10 * i,
lvt_val | APIC_LVT_MASKED);
}
+ apic_update_lvtt(apic);
atomic_set(&apic->lapic_timer.pending, 0);
}
@@ -1304,20 +1316,13 @@ static int apic_reg_write(struct kvm_lap
break;
- case APIC_LVTT: {
- u32 timer_mode = val & apic->lapic_timer.timer_mode_mask;
-
- if (apic->lapic_timer.timer_mode != timer_mode) {
- apic->lapic_timer.timer_mode = timer_mode;
- hrtimer_cancel(&apic->lapic_timer.timer);
- }
-
+ case APIC_LVTT:
if (!kvm_apic_sw_enabled(apic))
val |= APIC_LVT_MASKED;
val &= (apic_lvt_mask[0] | apic->lapic_timer.timer_mode_mask);
apic_set_reg(apic, APIC_LVTT, val);
+ apic_update_lvtt(apic);
break;
- }
case APIC_TMICT:
if (apic_lvtt_tscdeadline(apic))
@@ -1552,7 +1557,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vc
for (i = 0; i < APIC_LVT_NUM; i++)
apic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
- apic->lapic_timer.timer_mode = 0;
+ apic_update_lvtt(apic);
apic_set_reg(apic, APIC_LVT0,
SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
@@ -1778,6 +1783,7 @@ void kvm_apic_post_state_restore(struct
apic_update_ppr(apic);
hrtimer_cancel(&apic->lapic_timer.timer);
+ apic_update_lvtt(apic);
update_divide_count(apic);
start_apic_timer(apic);
apic->irr_pending = true;
Patches currently in stable-queue which might be from rkrcmar@xxxxxxxxxx are
queue-4.0/kvm-x86-fix-lapic.timer_mode-on-restore.patch
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