From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
SDM 10.5.4.1 TSC-Deadline Mode mentioned that "Transitioning between TSC-Deadline
mode and other timer modes also disarms the timer". So the APIC Timer Initial Count
Register for one-shot/periodic mode should be reset. This patch do it.
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
arch/x86/include/asm/apicdef.h | 1 +
arch/x86/kvm/lapic.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h
index c46bb99..7fde8e9 100644
--- a/arch/x86/include/asm/apicdef.h
+++ b/arch/x86/include/asm/apicdef.h
@@ -100,6 +100,7 @@
#define APIC_TIMER_BASE_CLKIN 0x0
#define APIC_TIMER_BASE_TMBASE 0x1
#define APIC_TIMER_BASE_DIV 0x2
+#define APIC_LVT_TIMER_MASK (3 << 17)
#define APIC_LVT_TIMER_ONESHOT (0 << 17)
#define APIC_LVT_TIMER_PERIODIC (1 << 17)
#define APIC_LVT_TIMER_TSCDEADLINE (2 << 17)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 69c5612..6723e2c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1307,6 +1307,9 @@ static void apic_update_lvtt(struct kvm_lapic *apic)
apic->lapic_timer.timer_mode_mask;
if (apic->lapic_timer.timer_mode != timer_mode) {
+ if (apic_lvtt_tscdeadline(apic) != (timer_mode ==
+ APIC_LVT_TIMER_TSCDEADLINE))
+ kvm_lapic_set_reg(apic, APIC_TMICT, 0);
apic->lapic_timer.timer_mode = timer_mode;
hrtimer_cancel(&apic->lapic_timer.timer);
}
--
2.7.4
