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Diffstat (limited to 'arch/x86/kvm/lapic.c')
-rw-r--r--arch/x86/kvm/lapic.c334
1 files changed, 246 insertions, 88 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index ae99d83..1ae5ceb 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -32,8 +32,11 @@
#include <asm/current.h>
#include <asm/apicdef.h>
#include <asm/atomic.h>
+#include <asm/apicdef.h>
#include "kvm_cache_regs.h"
#include "irq.h"
+#include "trace.h"
+#include "x86.h"
#ifndef CONFIG_X86_64
#define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
@@ -141,6 +144,26 @@ static inline int apic_lvt_nmi_mode(u32 lvt_val)
return (lvt_val & (APIC_MODE_MASK | APIC_LVT_MASKED)) == APIC_DM_NMI;
}
+void kvm_apic_set_version(struct kvm_vcpu *vcpu)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+ struct kvm_cpuid_entry2 *feat;
+ u32 v = APIC_VERSION;
+
+ if (!irqchip_in_kernel(vcpu->kvm))
+ return;
+
+ feat = kvm_find_cpuid_entry(apic->vcpu, 0x1, 0);
+ if (feat && (feat->ecx & (1 << (X86_FEATURE_X2APIC & 31))))
+ v |= APIC_LVR_DIRECTED_EOI;
+ apic_set_reg(apic, APIC_LVR, v);
+}
+
+static inline int apic_x2apic_mode(struct kvm_lapic *apic)
+{
+ return apic->vcpu->arch.apic_base & X2APIC_ENABLE;
+}
+
static unsigned int apic_lvt_mask[APIC_LVT_NUM] = {
LVT_MASK | APIC_LVT_TIMER_PERIODIC, /* LVTT */
LVT_MASK | APIC_MODE_MASK, /* LVTTHMR */
@@ -165,36 +188,52 @@ static int find_highest_vector(void *bitmap)
static inline int apic_test_and_set_irr(int vec, struct kvm_lapic *apic)
{
+ apic->irr_pending = true;
return apic_test_and_set_vector(vec, apic->regs + APIC_IRR);
}
-static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
+static inline int apic_search_irr(struct kvm_lapic *apic)
{
- apic_clear_vector(vec, apic->regs + APIC_IRR);
+ return find_highest_vector(apic->regs + APIC_IRR);
}
static inline int apic_find_highest_irr(struct kvm_lapic *apic)
{
int result;
- result = find_highest_vector(apic->regs + APIC_IRR);
+ if (!apic->irr_pending)
+ return -1;
+
+ result = apic_search_irr(apic);
ASSERT(result == -1 || result >= 16);
return result;
}
+static inline void apic_clear_irr(int vec, struct kvm_lapic *apic)
+{
+ apic->irr_pending = false;
+ apic_clear_vector(vec, apic->regs + APIC_IRR);
+ if (apic_search_irr(apic) != -1)
+ apic->irr_pending = true;
+}
+
int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic = vcpu->arch.apic;
int highest_irr;
+ /* This may race with setting of irr in __apic_accept_irq() and
+ * value returned may be wrong, but kvm_vcpu_kick() in __apic_accept_irq
+ * will cause vmexit immediately and the value will be recalculated
+ * on the next vmentry.
+ */
if (!apic)
return 0;
highest_irr = apic_find_highest_irr(apic);
return highest_irr;
}
-EXPORT_SYMBOL_GPL(kvm_lapic_find_highest_irr);
static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
int vector, int level, int trig_mode);
@@ -251,7 +290,12 @@ int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest)
int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda)
{
int result = 0;
- u8 logical_id;
+ u32 logical_id;
+
+ if (apic_x2apic_mode(apic)) {
+ logical_id = apic_get_reg(apic, APIC_LDR);
+ return logical_id & mda;
+ }
logical_id = GET_APIC_LOGICAL_ID(apic_get_reg(apic, APIC_LDR));
@@ -331,6 +375,8 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
break;
result = !apic_test_and_set_irr(vector, apic);
+ trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
+ trig_mode, vector, !result);
if (!result) {
if (trig_mode)
apic_debug("level trig mode repeatedly for "
@@ -425,7 +471,11 @@ static void apic_set_eoi(struct kvm_lapic *apic)
trigger_mode = IOAPIC_LEVEL_TRIG;
else
trigger_mode = IOAPIC_EDGE_TRIG;
- kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
+ if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)) {
+ mutex_lock(&apic->vcpu->kvm->irq_lock);
+ kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
+ mutex_unlock(&apic->vcpu->kvm->irq_lock);
+ }
}
static void apic_send_ipi(struct kvm_lapic *apic)
@@ -440,7 +490,12 @@ static void apic_send_ipi(struct kvm_lapic *apic)
irq.level = icr_low & APIC_INT_ASSERT;
irq.trig_mode = icr_low & APIC_INT_LEVELTRIG;
irq.shorthand = icr_low & APIC_SHORT_MASK;
- irq.dest_id = GET_APIC_DEST_FIELD(icr_high);
+ if (apic_x2apic_mode(apic))
+ irq.dest_id = icr_high;
+ else
+ irq.dest_id = GET_APIC_DEST_FIELD(icr_high);
+
+ trace_kvm_apic_ipi(icr_low, irq.dest_id);
apic_debug("icr_high 0x%x, icr_low 0x%x, "
"short_hand 0x%x, dest 0x%x, trig_mode 0x%x, level 0x%x, "
@@ -449,7 +504,9 @@ static void apic_send_ipi(struct kvm_lapic *apic)
irq.trig_mode, irq.level, irq.dest_mode, irq.delivery_mode,
irq.vector);
+ mutex_lock(&apic->vcpu->kvm->irq_lock);
kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq);
+ mutex_unlock(&apic->vcpu->kvm->irq_lock);
}
static u32 apic_get_tmcct(struct kvm_lapic *apic)
@@ -495,12 +552,16 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)
{
u32 val = 0;
- KVMTRACE_1D(APIC_ACCESS, apic->vcpu, (u32)offset, handler);
-
if (offset >= LAPIC_MMIO_LENGTH)
return 0;
switch (offset) {
+ case APIC_ID:
+ if (apic_x2apic_mode(apic))
+ val = kvm_apic_id(apic);
+ else
+ val = kvm_apic_id(apic) << 24;
+ break;
case APIC_ARBPRI:
printk(KERN_WARNING "Access APIC ARBPRI register "
"which is for P6\n");
@@ -522,21 +583,35 @@ static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset)
return val;
}
-static void apic_mmio_read(struct kvm_io_device *this,
- gpa_t address, int len, void *data)
+static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev)
+{
+ return container_of(dev, struct kvm_lapic, dev);
+}
+
+static int apic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
+ void *data)
{
- struct kvm_lapic *apic = (struct kvm_lapic *)this->private;
- unsigned int offset = address - apic->base_address;
unsigned char alignment = offset & 0xf;
u32 result;
+ /* this bitmask has a bit cleared for each reserver register */
+ static const u64 rmask = 0x43ff01ffffffe70cULL;
if ((alignment + len) > 4) {
- printk(KERN_ERR "KVM_APIC_READ: alignment error %lx %d",
- (unsigned long)address, len);
- return;
+ apic_debug("KVM_APIC_READ: alignment error %x %d\n",
+ offset, len);
+ return 1;
}
+
+ if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) {
+ apic_debug("KVM_APIC_READ: read reserved register %x\n",
+ offset);
+ return 1;
+ }
+
result = __apic_read(apic, offset & ~0xf);
+ trace_kvm_apic_read(offset, result);
+
switch (len) {
case 1:
case 2:
@@ -548,6 +623,28 @@ static void apic_mmio_read(struct kvm_io_device *this,
"should be 1,2, or 4 instead\n", len);
break;
}
+ return 0;
+}
+
+static int apic_mmio_in_range(struct kvm_lapic *apic, gpa_t addr)
+{
+ return apic_hw_enabled(apic) &&
+ addr >= apic->base_address &&
+ addr < apic->base_address + LAPIC_MMIO_LENGTH;
+}
+
+static int apic_mmio_read(struct kvm_io_device *this,
+ gpa_t address, int len, void *data)
+{
+ struct kvm_lapic *apic = to_lapic(this);
+ u32 offset = address - apic->base_address;
+
+ if (!apic_mmio_in_range(apic, address))
+ return -EOPNOTSUPP;
+
+ apic_reg_read(apic, offset, len, data);
+
+ return 0;
}
static void update_divide_count(struct kvm_lapic *apic)
@@ -573,6 +670,15 @@ static void start_apic_timer(struct kvm_lapic *apic)
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),
@@ -603,40 +709,18 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
apic->vcpu->kvm->arch.vapics_in_nmi_mode--;
}
-static void apic_mmio_write(struct kvm_io_device *this,
- gpa_t address, int len, const void *data)
+static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
{
- struct kvm_lapic *apic = (struct kvm_lapic *)this->private;
- unsigned int offset = address - apic->base_address;
- unsigned char alignment = offset & 0xf;
- u32 val;
-
- /*
- * APIC register must be aligned on 128-bits boundary.
- * 32/64/128 bits registers must be accessed thru 32 bits.
- * Refer SDM 8.4.1
- */
- if (len != 4 || alignment) {
- /* Don't shout loud, $infamous_os would cause only noise. */
- apic_debug("apic write: bad size=%d %lx\n",
- len, (long)address);
- return;
- }
-
- val = *(u32 *) data;
-
- /* too common printing */
- if (offset != APIC_EOI)
- apic_debug("%s: offset 0x%x with length 0x%x, and value is "
- "0x%x\n", __func__, offset, len, val);
-
- offset &= 0xff0;
+ int ret = 0;
- KVMTRACE_1D(APIC_ACCESS, apic->vcpu, (u32)offset, handler);
+ trace_kvm_apic_write(reg, val);
- switch (offset) {
+ switch (reg) {
case APIC_ID: /* Local APIC ID */
- apic_set_reg(apic, APIC_ID, val);
+ if (!apic_x2apic_mode(apic))
+ apic_set_reg(apic, APIC_ID, val);
+ else
+ ret = 1;
break;
case APIC_TASKPRI:
@@ -649,15 +733,24 @@ static void apic_mmio_write(struct kvm_io_device *this,
break;
case APIC_LDR:
- apic_set_reg(apic, APIC_LDR, val & APIC_LDR_MASK);
+ if (!apic_x2apic_mode(apic))
+ apic_set_reg(apic, APIC_LDR, val & APIC_LDR_MASK);
+ else
+ ret = 1;
break;
case APIC_DFR:
- apic_set_reg(apic, APIC_DFR, val | 0x0FFFFFFF);
+ if (!apic_x2apic_mode(apic))
+ apic_set_reg(apic, APIC_DFR, val | 0x0FFFFFFF);
+ else
+ ret = 1;
break;
- case APIC_SPIV:
- apic_set_reg(apic, APIC_SPIV, val & 0x3ff);
+ case APIC_SPIV: {
+ u32 mask = 0x3ff;
+ if (apic_get_reg(apic, APIC_LVR) & APIC_LVR_DIRECTED_EOI)
+ mask |= APIC_SPIV_DIRECTED_EOI;
+ apic_set_reg(apic, APIC_SPIV, val & mask);
if (!(val & APIC_SPIV_APIC_ENABLED)) {
int i;
u32 lvt_val;
@@ -672,7 +765,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
}
break;
-
+ }
case APIC_ICR:
/* No delay here, so we always clear the pending bit */
apic_set_reg(apic, APIC_ICR, val & ~(1 << 12));
@@ -680,7 +773,9 @@ static void apic_mmio_write(struct kvm_io_device *this,
break;
case APIC_ICR2:
- apic_set_reg(apic, APIC_ICR2, val & 0xff000000);
+ if (!apic_x2apic_mode(apic))
+ val &= 0xff000000;
+ apic_set_reg(apic, APIC_ICR2, val);
break;
case APIC_LVT0:
@@ -694,8 +789,8 @@ static void apic_mmio_write(struct kvm_io_device *this,
if (!apic_sw_enabled(apic))
val |= APIC_LVT_MASKED;
- val &= apic_lvt_mask[(offset - APIC_LVTT) >> 4];
- apic_set_reg(apic, offset, val);
+ val &= apic_lvt_mask[(reg - APIC_LVTT) >> 4];
+ apic_set_reg(apic, reg, val);
break;
@@ -703,7 +798,7 @@ static void apic_mmio_write(struct kvm_io_device *this,
hrtimer_cancel(&apic->lapic_timer.timer);
apic_set_reg(apic, APIC_TMICT, val);
start_apic_timer(apic);
- return;
+ break;
case APIC_TDCR:
if (val & 4)
@@ -712,27 +807,59 @@ static void apic_mmio_write(struct kvm_io_device *this,
update_divide_count(apic);
break;
+ case APIC_ESR:
+ if (apic_x2apic_mode(apic) && val != 0) {
+ printk(KERN_ERR "KVM_WRITE:ESR not zero %x\n", val);
+ ret = 1;
+ }
+ break;
+
+ case APIC_SELF_IPI:
+ if (apic_x2apic_mode(apic)) {
+ apic_reg_write(apic, APIC_ICR, 0x40000 | (val & 0xff));
+ } else
+ ret = 1;
+ break;
default:
- apic_debug("Local APIC Write to read-only register %x\n",
- offset);
+ ret = 1;
break;
}
-
+ if (ret)
+ apic_debug("Local APIC Write to read-only register %x\n", reg);
+ return ret;
}
-static int apic_mmio_range(struct kvm_io_device *this, gpa_t addr,
- int len, int size)
+static int apic_mmio_write(struct kvm_io_device *this,
+ gpa_t address, int len, const void *data)
{
- struct kvm_lapic *apic = (struct kvm_lapic *)this->private;
- int ret = 0;
+ struct kvm_lapic *apic = to_lapic(this);
+ unsigned int offset = address - apic->base_address;
+ u32 val;
+ if (!apic_mmio_in_range(apic, address))
+ return -EOPNOTSUPP;
- if (apic_hw_enabled(apic) &&
- (addr >= apic->base_address) &&
- (addr < (apic->base_address + LAPIC_MMIO_LENGTH)))
- ret = 1;
+ /*
+ * APIC register must be aligned on 128-bits boundary.
+ * 32/64/128 bits registers must be accessed thru 32 bits.
+ * Refer SDM 8.4.1
+ */
+ if (len != 4 || (offset & 0xf)) {
+ /* Don't shout loud, $infamous_os would cause only noise. */
+ apic_debug("apic write: bad size=%d %lx\n", len, (long)address);
+ return 0;
+ }
- return ret;
+ val = *(u32*)data;
+
+ /* too common printing */
+ if (offset != APIC_EOI)
+ apic_debug("%s: offset 0x%x with length 0x%x, and value is "
+ "0x%x\n", __func__, offset, len, val);
+
+ apic_reg_write(apic, offset & 0xff0, val);
+
+ return 0;
}
void kvm_free_lapic(struct kvm_vcpu *vcpu)
@@ -763,7 +890,6 @@ void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8)
apic_set_tpr(apic, ((cr8 & 0x0f) << 4)
| (apic_get_reg(apic, APIC_TASKPRI) & 4));
}
-EXPORT_SYMBOL_GPL(kvm_lapic_set_tpr);
u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
{
@@ -776,7 +902,6 @@ u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
return (tpr & 0xf0) >> 4;
}
-EXPORT_SYMBOL_GPL(kvm_lapic_get_cr8);
void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
{
@@ -787,10 +912,16 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
vcpu->arch.apic_base = value;
return;
}
- if (apic->vcpu->vcpu_id)
+
+ if (!kvm_vcpu_is_bsp(apic->vcpu))
value &= ~MSR_IA32_APICBASE_BSP;
vcpu->arch.apic_base = value;
+ if (apic_x2apic_mode(apic)) {
+ u32 id = kvm_apic_id(apic);
+ u32 ldr = ((id & ~0xf) << 16) | (1 << (id & 0xf));
+ apic_set_reg(apic, APIC_LDR, ldr);
+ }
apic->base_address = apic->vcpu->arch.apic_base &
MSR_IA32_APICBASE_BASE;
@@ -800,12 +931,6 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
}
-u64 kvm_lapic_get_base(struct kvm_vcpu *vcpu)
-{
- return vcpu->arch.apic_base;
-}
-EXPORT_SYMBOL_GPL(kvm_lapic_get_base);
-
void kvm_lapic_reset(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic;
@@ -821,7 +946,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
hrtimer_cancel(&apic->lapic_timer.timer);
apic_set_reg(apic, APIC_ID, vcpu->vcpu_id << 24);
- apic_set_reg(apic, APIC_LVR, APIC_VERSION);
+ kvm_apic_set_version(apic->vcpu);
for (i = 0; i < APIC_LVT_NUM; i++)
apic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
@@ -842,9 +967,10 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
apic_set_reg(apic, APIC_ISR + 0x10 * i, 0);
apic_set_reg(apic, APIC_TMR + 0x10 * i, 0);
}
+ apic->irr_pending = false;
update_divide_count(apic);
atomic_set(&apic->lapic_timer.pending, 0);
- if (vcpu->vcpu_id == 0)
+ if (kvm_vcpu_is_bsp(vcpu))
vcpu->arch.apic_base |= MSR_IA32_APICBASE_BSP;
apic_update_ppr(apic);
@@ -855,7 +981,6 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
vcpu, kvm_apic_id(apic),
vcpu->arch.apic_base, apic->base_address);
}
-EXPORT_SYMBOL_GPL(kvm_lapic_reset);
bool kvm_apic_present(struct kvm_vcpu *vcpu)
{
@@ -866,7 +991,6 @@ int kvm_lapic_enabled(struct kvm_vcpu *vcpu)
{
return kvm_apic_present(vcpu) && apic_sw_enabled(vcpu->arch.apic);
}
-EXPORT_SYMBOL_GPL(kvm_lapic_enabled);
/*
*----------------------------------------------------------------------
@@ -917,6 +1041,11 @@ static struct kvm_timer_ops lapic_timer_ops = {
.is_periodic = lapic_is_periodic,
};
+static const struct kvm_io_device_ops apic_mmio_ops = {
+ .read = apic_mmio_read,
+ .write = apic_mmio_write,
+};
+
int kvm_create_lapic(struct kvm_vcpu *vcpu)
{
struct kvm_lapic *apic;
@@ -945,16 +1074,13 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
apic->lapic_timer.timer.function = kvm_timer_fn;
apic->lapic_timer.t_ops = &lapic_timer_ops;
apic->lapic_timer.kvm = vcpu->kvm;
- apic->lapic_timer.vcpu_id = vcpu->vcpu_id;
+ apic->lapic_timer.vcpu = vcpu;
apic->base_address = APIC_DEFAULT_PHYS_BASE;
vcpu->arch.apic_base = APIC_DEFAULT_PHYS_BASE;
kvm_lapic_reset(vcpu);
- apic->dev.read = apic_mmio_read;
- apic->dev.write = apic_mmio_write;
- apic->dev.in_range = apic_mmio_range;
- apic->dev.private = apic;
+ kvm_iodevice_init(&apic->dev, &apic_mmio_ops);
return 0;
nomem_free_apic:
@@ -962,7 +1088,6 @@ nomem_free_apic:
nomem:
return -ENOMEM;
}
-EXPORT_SYMBOL_GPL(kvm_create_lapic);
int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu)
{
@@ -985,7 +1110,7 @@ int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
u32 lvt0 = apic_get_reg(vcpu->arch.apic, APIC_LVT0);
int r = 0;
- if (vcpu->vcpu_id == 0) {
+ if (kvm_vcpu_is_bsp(vcpu)) {
if (!apic_hw_enabled(vcpu->arch.apic))
r = 1;
if ((lvt0 & APIC_LVT_MASKED) == 0 &&
@@ -1025,7 +1150,8 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu)
apic->base_address = vcpu->arch.apic_base &
MSR_IA32_APICBASE_BASE;
- apic_set_reg(apic, APIC_LVR, APIC_VERSION);
+ kvm_apic_set_version(vcpu);
+
apic_update_ppr(apic);
hrtimer_cancel(&apic->lapic_timer.timer);
update_divide_count(apic);
@@ -1092,3 +1218,35 @@ void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
vcpu->arch.apic->vapic_addr = vapic_addr;
}
+
+int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+ u32 reg = (msr - APIC_BASE_MSR) << 4;
+
+ if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
+ return 1;
+
+ /* if this is ICR write vector before command */
+ if (msr == 0x830)
+ apic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
+ return apic_reg_write(apic, reg, (u32)data);
+}
+
+int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+ u32 reg = (msr - APIC_BASE_MSR) << 4, low, high = 0;
+
+ if (!irqchip_in_kernel(vcpu->kvm) || !apic_x2apic_mode(apic))
+ return 1;
+
+ if (apic_reg_read(apic, reg, 4, &low))
+ return 1;
+ if (msr == 0x830)
+ apic_reg_read(apic, APIC_ICR2, 4, &high);
+
+ *data = (((u64)high) << 32) | low;
+
+ return 0;
+}