[PATCH 06/46] KVM: x2apic interface to lapic

From: Avi Kivity
Date: Sun Aug 23 2009 - 08:04:29 EST


From: Gleb Natapov <gleb@xxxxxxxxxx>

This patch implements MSR interface to local apic as defines by x2apic
Intel specification.

Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 217 ++++++++++++++++++++++++++++++++++++-------------
arch/x86/kvm/lapic.h | 2 +
arch/x86/kvm/x86.c | 7 ++-
3 files changed, 167 insertions(+), 59 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 62ea2ab..dc6bec2 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -32,6 +32,7 @@
#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"
@@ -158,6 +159,11 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu)
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 */
@@ -284,7 +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));

@@ -477,7 +488,10 @@ 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);

apic_debug("icr_high 0x%x, icr_low 0x%x, "
"short_hand 0x%x, dest 0x%x, trig_mode 0x%x, level 0x%x, "
@@ -564,28 +578,26 @@ static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev)
return container_of(dev, struct kvm_lapic, dev);
}

-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)
+static int apic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
+ void *data)
{
- struct kvm_lapic *apic = to_lapic(this);
- unsigned int offset = address - apic->base_address;
unsigned char alignment = offset & 0xf;
u32 result;
- if (!apic_mmio_in_range(apic, address))
- return -EOPNOTSUPP;
+ /* 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 0;
+ printk(KERN_ERR "KVM_APIC_READ: alignment error %x %d\n",
+ offset, len);
+ return 1;
+ }
+
+ if (offset > 0x3f0 || !(rmask & (1ULL << (offset >> 4)))) {
+ printk(KERN_ERR "KVM_APIC_READ: read reserved register %x\n",
+ offset);
+ return 1;
}
+
result = __apic_read(apic, offset & ~0xf);

trace_kvm_apic_read(offset, result);
@@ -604,6 +616,27 @@ static int apic_mmio_read(struct kvm_io_device *this,
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)
{
u32 tmp1, tmp2, tdcr;
@@ -657,42 +690,18 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val)
apic->vcpu->kvm->arch.vapics_in_nmi_mode--;
}

-static int 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 = to_lapic(this);
- unsigned int offset = address - apic->base_address;
- unsigned char alignment = offset & 0xf;
- u32 val;
- if (!apic_mmio_in_range(apic, address))
- return -EOPNOTSUPP;
-
- /*
- * 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 0;
- }
-
- 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);
+ int ret = 0;

- offset &= 0xff0;
+ trace_kvm_apic_write(reg, val);

- trace_kvm_apic_write(offset, 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:
@@ -705,11 +714,17 @@ static int 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: {
@@ -739,7 +754,9 @@ static int 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:
@@ -753,8 +770,8 @@ static int 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;

@@ -762,7 +779,7 @@ static int 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 0;
+ break;

case APIC_TDCR:
if (val & 4)
@@ -771,11 +788,58 @@ static int 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_write(struct kvm_io_device *this,
+ gpa_t address, int len, const void *data)
+{
+ 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;
+
+ /*
+ * 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;
+ }
+
+ 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;
}

@@ -834,6 +898,11 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value)
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;

@@ -1130,3 +1199,35 @@ 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;
+}
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index bc1c524..40010b0 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -46,4 +46,6 @@ 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);

+int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data);
+int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data);
#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 086f931..a50c832 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -867,6 +867,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
case MSR_IA32_APICBASE:
kvm_set_apic_base(vcpu, data);
break;
+ case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
+ return kvm_x2apic_msr_write(vcpu, msr, data);
case MSR_IA32_MISC_ENABLE:
vcpu->arch.ia32_misc_enable_msr = data;
break;
@@ -1065,6 +1067,9 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
case MSR_IA32_APICBASE:
data = kvm_get_apic_base(vcpu);
break;
+ case APIC_BASE_MSR ... APIC_BASE_MSR + 0x3ff:
+ return kvm_x2apic_msr_read(vcpu, msr, pdata);
+ break;
case MSR_IA32_MISC_ENABLE:
data = vcpu->arch.ia32_misc_enable_msr;
break;
@@ -1469,7 +1474,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
0 /* Reserved */ | F(CX16) | 0 /* xTPR Update, PDCM */ |
0 /* Reserved, DCA */ | F(XMM4_1) |
- F(XMM4_2) | 0 /* x2APIC */ | F(MOVBE) | F(POPCNT) |
+ F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
0 /* Reserved, XSAVE, OSXSAVE */;
/* cpuid 0x80000001.ecx */
const u32 kvm_supported_word6_x86_features =
--
1.6.4.1

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