>From 4d5b83aba40ce0d421add9a41a6c591a8590a32e Mon Sep 17 00:00:00 2001
From: Liu, Jinsong <jinsong.liu@xxxxxxxxx>
Date: Thu, 22 Sep 2011 14:00:08 +0800
Subject: [PATCH 2/2] KVM: emulate lapic tsc deadline timer for guest
This patch emulate lapic tsc deadline timer for guest:
Enumerate tsc deadline timer capability by CPUID;
Enable tsc deadline timer mode by lapic MMIO;
Start tsc deadline timer by WRMSR;
Signed-off-by: Liu, Jinsong <jinsong.liu@xxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 +
arch/x86/kvm/kvm_timer.h | 2 +
arch/x86/kvm/lapic.c | 123 ++++++++++++++++++++++++++++++++-------
arch/x86/kvm/lapic.h | 3 +
arch/x86/kvm/x86.c | 16 +++++-
5 files changed, 123 insertions(+), 23 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6ab4241..b9d4291 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -673,6 +673,8 @@ u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn);
extern bool tdp_enabled;
+u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu);
+
/* control of guest tsc rate supported? */
extern bool kvm_has_tsc_control;
/* minimum supported tsc_khz for guests */
diff --git a/arch/x86/kvm/kvm_timer.h b/arch/x86/kvm/kvm_timer.h
index 64bc6ea..497dbaa 100644
--- a/arch/x86/kvm/kvm_timer.h
+++ b/arch/x86/kvm/kvm_timer.h
@@ -2,6 +2,8 @@
struct kvm_timer {
struct hrtimer timer;
s64 period; /* unit: ns */
+ u32 timer_mode_mask;
+ u64 tscdeadline;
atomic_t pending; /* accumulated triggered timers */
bool reinject;
struct kvm_timer_ops *t_ops;
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 57dcbd4..66b64b8 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -135,9 +135,23 @@ static inline int apic_lvt_vector(struct kvm_lapic *apic, int lvt_type)
return apic_get_reg(apic, lvt_type) & APIC_VECTOR_MASK;
}
+static inline int apic_lvtt_oneshot(struct kvm_lapic *apic)
+{
+ return ((apic_get_reg(apic, APIC_LVTT) &
+ apic->lapic_timer.timer_mode_mask) == APIC_LVT_TIMER_ONESHOT);
+}
+
static inline int apic_lvtt_period(struct kvm_lapic *apic)
{
- return apic_get_reg(apic, APIC_LVTT) & APIC_LVT_TIMER_PERIODIC;
+ return ((apic_get_reg(apic, APIC_LVTT) &
+ apic->lapic_timer.timer_mode_mask) == APIC_LVT_TIMER_PERIODIC);
+}
+
+static inline int apic_lvtt_tscdeadline(struct kvm_lapic *apic)
+{
+ return ((apic_get_reg(apic, APIC_LVTT) &
+ apic->lapic_timer.timer_mode_mask) ==
+ APIC_LVT_TIMER_TSCDEADLINE);
}
static inline int apic_lvt_nmi_mode(u32 lvt_val)
@@ -166,7 +180,7 @@ static inline int apic_x2apic_mode(struct kvm_lapic *apic)
}
static unsigned int apic_lvt_mask[APIC_LVT_NUM] = {
- LVT_MASK | APIC_LVT_TIMER_PERIODIC, /* LVTT */
+ LVT_MASK , /* part LVTT mask, timer mode mask added at runtime */
LVT_MASK | APIC_MODE_MASK, /* LVTTHMR */
LVT_MASK | APIC_MODE_MASK, /* LVTPC */
LINT_MASK, LINT_MASK, /* LVT0-1 */
@@ -570,6 +584,9 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)
break;
case APIC_TMCCT: /* Timer CCR */
+ if (apic_lvtt_tscdeadline(apic))
+ return 0;
+
val = apic_get_tmcct(apic);
break;
@@ -664,29 +681,32 @@ static void update_divide_count(struct kvm_lapic *apic)
static void start_apic_timer(struct kvm_lapic *apic)
{
- ktime_t now = apic->lapic_timer.timer.base->get_time();
-
- apic->lapic_timer.period = (u64)apic_get_reg(apic, APIC_TMICT) *
- APIC_BUS_CYCLE_NS * apic->divide_count;
+ ktime_t now;
atomic_set(&apic->lapic_timer.pending, 0);
- if (!apic->lapic_timer.period)
- return;
- /*
- * Do not allow the guest to program periodic timers with small
- * interval, since the hrtimers are not throttled by the host
- * scheduler.
- */
- if (apic_lvtt_period(apic)) {
- if (apic->lapic_timer.period < NSEC_PER_MSEC/2)
- apic->lapic_timer.period = NSEC_PER_MSEC/2;
- }
+ if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) {
+ /* lapic timer in oneshot or peroidic mode */
+ now = apic->lapic_timer.timer.base->get_time();
+ apic->lapic_timer.period = (u64)apic_get_reg(apic, APIC_TMICT)
+ * APIC_BUS_CYCLE_NS * apic->divide_count;
+
+ if (!apic->lapic_timer.period)
+ return;
+ /*
+ * Do not allow the guest to program periodic timers with small
+ * interval, since the hrtimers are not throttled by the host
+ * scheduler.
+ */
+ if (apic_lvtt_period(apic)) {
+ if (apic->lapic_timer.period < NSEC_PER_MSEC/2)
+ apic->lapic_timer.period = NSEC_PER_MSEC/2;
+ }
- hrtimer_start(&apic->lapic_timer.timer,
- ktime_add_ns(now, apic->lapic_timer.period),
- HRTIMER_MODE_ABS);
+ hrtimer_start(&apic->lapic_timer.timer,
+ ktime_add_ns(now, apic->lapic_timer.period),
+ HRTIMER_MODE_ABS);
- apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
+ apic_debug("%s: bus cycle is %" PRId64 "ns, now 0x%016"
PRIx64 ", "
"timer initial count 0x%x, period %lldns, "
"expire @ 0x%016" PRIx64 ".\n", __func__,
@@ -695,6 +715,29 @@ static void start_apic_timer(struct kvm_lapic *apic)
apic->lapic_timer.period,
ktime_to_ns(ktime_add_ns(now,
apic->lapic_timer.period)));
+ } else if (apic_lvtt_tscdeadline(apic)) {
+ /* lapic timer in tsc deadline mode */
+ u64 guest_tsc, tscdeadline = apic->lapic_timer.tscdeadline;
+ u64 ns = 0;
+ struct kvm_vcpu *vcpu = apic->vcpu;
+ unsigned long this_tsc_khz = vcpu_tsc_khz(vcpu);
+ unsigned long flags;
+
+ if (unlikely(!tscdeadline || !this_tsc_khz))
+ return;
+
+ local_irq_save(flags);
+
+ now = apic->lapic_timer.timer.base->get_time();
+ guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu);
+ if (likely(tscdeadline > guest_tsc))
+ ns = (tscdeadline - guest_tsc)
+ * 1000000L / this_tsc_khz;
+ hrtimer_start(&apic->lapic_timer.timer,
+ ktime_add_ns(now, ns), HRTIMER_MODE_ABS);
+
+ local_irq_restore(flags);
+ }
}
static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
@@ -782,7 +825,6 @@ static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
case APIC_LVT0:
apic_manage_nmi_watchdog(apic, val);
- case APIC_LVTT:
case APIC_LVTTHMR:
case APIC_LVTPC:
case APIC_LVT1:
@@ -796,7 +838,22 @@ static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
break;
+ case APIC_LVTT:
+ if ((apic_get_reg(apic, APIC_LVTT) &
+ apic->lapic_timer.timer_mode_mask) !=
+ (val & apic->lapic_timer.timer_mode_mask))
+ hrtimer_cancel(&apic->lapic_timer.timer);
+
+ if (!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);
+ break;
+
case APIC_TMICT:
+ if (apic_lvtt_tscdeadline(apic))
+ break;
+
hrtimer_cancel(&apic->lapic_timer.timer);
apic_set_reg(apic, APIC_TMICT, val);
start_apic_timer(apic);
@@ -883,6 +940,28 @@ void kvm_free_lapic(struct kvm_vcpu *vcpu)
*----------------------------------------------------------------------
*/
+u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+
+ if (apic_lvtt_oneshot(apic) || apic_lvtt_period(apic))
+ return 0;
+
+ return apic->lapic_timer.tscdeadline;
+}
+
+void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+
+ if (apic_lvtt_oneshot(apic) || apic_lvtt_period(apic))
+ return;
+
+ hrtimer_cancel(&apic->lapic_timer.timer);
+ apic->lapic_timer.tscdeadline = data;
+ start_apic_timer(apic);
+}
+
void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8)
{
struct kvm_lapic *apic = vcpu->arch.apic;
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 52c9e6b..10c6ee6 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -41,6 +41,9 @@ int kvm_lapic_enabled(struct kvm_vcpu *vcpu);
bool kvm_apic_present(struct kvm_vcpu *vcpu);
int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu);
+u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu);
+void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data);
+
void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr);
void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu);
void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6b37f18..382c0b8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -610,6 +610,13 @@ static void update_cpuid(struct kvm_vcpu *vcpu)
if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
best->ecx |= bit(X86_FEATURE_OSXSAVE);
}
+
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
+ best->function == 0x1) {
+ best->ecx |= bit(X86_FEATURE_TSC_DEADLINE_TIMER);
+ vcpu->arch.apic->lapic_timer.timer_mode_mask = (3 << 17);
+ } else
+ vcpu->arch.apic->lapic_timer.timer_mode_mask = (1 << 17);
}
int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
@@ -825,6 +832,7 @@ static u32 msrs_to_save[] = {
static unsigned num_msrs_to_save;
static u32 emulated_msrs[] = {
+ MSR_IA32_TSCDEADLINE,
MSR_IA32_MISC_ENABLE,
MSR_IA32_MCG_STATUS,
MSR_IA32_MCG_CTL,
@@ -1000,7 +1008,7 @@ static inline int kvm_tsc_changes_freq(void)
return ret;
}
-static u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
+u64 vcpu_tsc_khz(struct kvm_vcpu *vcpu)
{
if (vcpu->arch.virtual_tsc_khz)
return vcpu->arch.virtual_tsc_khz;
@@ -1564,6 +1572,9 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
break;
case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
return kvm_x2apic_msr_write(vcpu, msr, data);
+ case MSR_IA32_TSCDEADLINE:
+ kvm_set_lapic_tscdeadline_msr(vcpu, data);
+ break;
case MSR_IA32_MISC_ENABLE:
vcpu->arch.ia32_misc_enable_msr = data;
break;
@@ -1893,6 +1904,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
return kvm_x2apic_msr_read(vcpu, msr, pdata);
break;
+ case MSR_IA32_TSCDEADLINE:
+ data = kvm_get_lapic_tscdeadline_msr(vcpu);
+ break;
case MSR_IA32_MISC_ENABLE:
data = vcpu->arch.ia32_misc_enable_msr;
break;
--
1.6.5.6
Attachment:
kvm-tsc-deadline-timer.patch
Description: kvm-tsc-deadline-timer.patch
