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-rw-r--r--arch/x86/kvm/lapic.c107
1 files changed, 84 insertions, 23 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 05a6f69fe589..3e6a53210cc4 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -68,6 +68,29 @@ static bool lapic_timer_advance_dynamic __read_mostly;
/* step-by-step approximation to mitigate fluctuation */
#define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8
+static __always_inline u64 __kvm_lapic_get_reg64(char *regs, int reg)
+{
+ BUILD_BUG_ON(reg != APIC_ICR);
+ return *((u64 *) (regs + reg));
+}
+
+static __always_inline u64 kvm_lapic_get_reg64(struct kvm_lapic *apic, int reg)
+{
+ return __kvm_lapic_get_reg64(apic->regs, reg);
+}
+
+static __always_inline void __kvm_lapic_set_reg64(char *regs, int reg, u64 val)
+{
+ BUILD_BUG_ON(reg != APIC_ICR);
+ *((u64 *) (regs + reg)) = val;
+}
+
+static __always_inline void kvm_lapic_set_reg64(struct kvm_lapic *apic,
+ int reg, u64 val)
+{
+ __kvm_lapic_set_reg64(apic->regs, reg, val);
+}
+
static inline int apic_test_vector(int vec, void *bitmap)
{
return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec));
@@ -1397,7 +1420,6 @@ static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
APIC_REGS_MASK(APIC_IRR, APIC_ISR_NR) |
APIC_REG_MASK(APIC_ESR) |
APIC_REG_MASK(APIC_ICR) |
- APIC_REG_MASK(APIC_ICR2) |
APIC_REG_MASK(APIC_LVTT) |
APIC_REG_MASK(APIC_LVTTHMR) |
APIC_REG_MASK(APIC_LVTPC) |
@@ -1408,9 +1430,16 @@ static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len,
APIC_REG_MASK(APIC_TMCCT) |
APIC_REG_MASK(APIC_TDCR);
- /* ARBPRI is not valid on x2APIC */
+ /*
+ * ARBPRI and ICR2 are not valid in x2APIC mode. WARN if KVM reads ICR
+ * in x2APIC mode as it's an 8-byte register in x2APIC and needs to be
+ * manually handled by the caller.
+ */
if (!apic_x2apic_mode(apic))
- valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI);
+ valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI) |
+ APIC_REG_MASK(APIC_ICR2);
+ else
+ WARN_ON_ONCE(offset == APIC_ICR);
if (alignment + len > 4)
return 1;
@@ -2054,16 +2083,18 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
break;
}
case APIC_ICR:
+ WARN_ON_ONCE(apic_x2apic_mode(apic));
+
/* No delay here, so we always clear the pending bit */
val &= ~APIC_ICR_BUSY;
kvm_apic_send_ipi(apic, val, kvm_lapic_get_reg(apic, APIC_ICR2));
kvm_lapic_set_reg(apic, APIC_ICR, val);
break;
-
case APIC_ICR2:
- if (!apic_x2apic_mode(apic))
- val &= 0xff000000;
- kvm_lapic_set_reg(apic, APIC_ICR2, val);
+ if (apic_x2apic_mode(apic))
+ ret = 1;
+ else
+ kvm_lapic_set_reg(apic, APIC_ICR2, val & 0xff000000);
break;
case APIC_LVT0:
@@ -2353,8 +2384,12 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event)
if (!apic_x2apic_mode(apic))
kvm_apic_set_ldr(apic, 0);
kvm_lapic_set_reg(apic, APIC_ESR, 0);
- kvm_lapic_set_reg(apic, APIC_ICR, 0);
- kvm_lapic_set_reg(apic, APIC_ICR2, 0);
+ if (!apic_x2apic_mode(apic)) {
+ kvm_lapic_set_reg(apic, APIC_ICR, 0);
+ kvm_lapic_set_reg(apic, APIC_ICR2, 0);
+ } else {
+ kvm_lapic_set_reg64(apic, APIC_ICR, 0);
+ }
kvm_lapic_set_reg(apic, APIC_TDCR, 0);
kvm_lapic_set_reg(apic, APIC_TMICT, 0);
for (i = 0; i < 8; i++) {
@@ -2571,6 +2606,7 @@ static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu,
if (apic_x2apic_mode(vcpu->arch.apic)) {
u32 *id = (u32 *)(s->regs + APIC_ID);
u32 *ldr = (u32 *)(s->regs + APIC_LDR);
+ u64 icr;
if (vcpu->kvm->arch.x2apic_format) {
if (*id != vcpu->vcpu_id)
@@ -2582,9 +2618,21 @@ static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu,
*id <<= 24;
}
- /* In x2APIC mode, the LDR is fixed and based on the id */
- if (set)
+ /*
+ * In x2APIC mode, the LDR is fixed and based on the id. And
+ * ICR is internally a single 64-bit register, but needs to be
+ * split to ICR+ICR2 in userspace for backwards compatibility.
+ */
+ if (set) {
*ldr = kvm_apic_calc_x2apic_ldr(*id);
+
+ icr = __kvm_lapic_get_reg(s->regs, APIC_ICR) |
+ (u64)__kvm_lapic_get_reg(s->regs, APIC_ICR2) << 32;
+ __kvm_lapic_set_reg64(s->regs, APIC_ICR, icr);
+ } else {
+ icr = __kvm_lapic_get_reg64(s->regs, APIC_ICR);
+ __kvm_lapic_set_reg(s->regs, APIC_ICR2, icr >> 32);
+ }
}
return 0;
@@ -2774,27 +2822,43 @@ int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
return 0;
}
+int kvm_x2apic_icr_write(struct kvm_lapic *apic, u64 data)
+{
+ data &= ~APIC_ICR_BUSY;
+
+ kvm_apic_send_ipi(apic, (u32)data, (u32)(data >> 32));
+ kvm_lapic_set_reg64(apic, APIC_ICR, data);
+ trace_kvm_apic_write(APIC_ICR, data);
+ return 0;
+}
+
static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data)
{
- u32 low, high = 0;
+ u32 low;
- if (kvm_lapic_reg_read(apic, reg, 4, &low))
- return 1;
+ if (reg == APIC_ICR) {
+ *data = kvm_lapic_get_reg64(apic, APIC_ICR);
+ return 0;
+ }
- if (reg == APIC_ICR &&
- WARN_ON_ONCE(kvm_lapic_reg_read(apic, APIC_ICR2, 4, &high)))
+ if (kvm_lapic_reg_read(apic, reg, 4, &low))
return 1;
- *data = (((u64)high) << 32) | low;
+ *data = low;
return 0;
}
static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data)
{
- /* For 64-bit ICR writes, set ICR2 (dest) before ICR (command). */
+ /*
+ * ICR is a 64-bit register in x2APIC mode (and Hyper'v PV vAPIC) and
+ * can be written as such, all other registers remain accessible only
+ * through 32-bit reads/writes.
+ */
if (reg == APIC_ICR)
- kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
+ return kvm_x2apic_icr_write(apic, data);
+
return kvm_lapic_reg_write(apic, reg, (u32)data);
}
@@ -2806,9 +2870,6 @@ int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic))
return 1;
- if (reg == APIC_ICR2)
- return 1;
-
return kvm_lapic_msr_write(apic, reg, data);
}
@@ -2820,7 +2881,7 @@ int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic))
return 1;
- if (reg == APIC_DFR || reg == APIC_ICR2)
+ if (reg == APIC_DFR)
return 1;
return kvm_lapic_msr_read(apic, reg, data);