diff options
| -rw-r--r-- | arch/x86/kvm/lapic.c | 53 | ||||
| -rw-r--r-- | arch/x86/kvm/lapic.h | 4 |
2 files changed, 55 insertions, 2 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 93c1574..805d887 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -107,6 +107,16 @@ static inline void apic_clear_vector(int vec, void *bitmap) clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); } +static inline int __apic_test_and_set_vector(int vec, void *bitmap) +{ + return __test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); +} + +static inline int __apic_test_and_clear_vector(int vec, void *bitmap) +{ + return __test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); +} + static inline int apic_hw_enabled(struct kvm_lapic *apic) { return (apic)->vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE; @@ -210,6 +220,16 @@ static int find_highest_vector(void *bitmap) return fls(word[word_offset << 2]) - 1 + (word_offset << 5); } +static u8 count_vectors(void *bitmap) +{ + u32 *word = bitmap; + int word_offset; + u8 count = 0; + for (word_offset = 0; word_offset < MAX_APIC_VECTOR >> 5; ++word_offset) + count += hweight32(word[word_offset << 2]); + return count; +} + static inline int apic_test_and_set_irr(int vec, struct kvm_lapic *apic) { apic->irr_pending = true; @@ -242,6 +262,27 @@ static inline void apic_clear_irr(int vec, struct kvm_lapic *apic) apic->irr_pending = true; } +static inline void apic_set_isr(int vec, struct kvm_lapic *apic) +{ + if (!__apic_test_and_set_vector(vec, apic->regs + APIC_ISR)) + ++apic->isr_count; + BUG_ON(apic->isr_count > MAX_APIC_VECTOR); + /* + * ISR (in service register) bit is set when injecting an interrupt. + * The highest vector is injected. Thus the latest bit set matches + * the highest bit in ISR. + */ + apic->highest_isr_cache = vec; +} + +static inline void apic_clear_isr(int vec, struct kvm_lapic *apic) +{ + if (__apic_test_and_clear_vector(vec, apic->regs + APIC_ISR)) + --apic->isr_count; + BUG_ON(apic->isr_count < 0); + apic->highest_isr_cache = -1; +} + int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; @@ -273,6 +314,10 @@ int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq) static inline int apic_find_highest_isr(struct kvm_lapic *apic) { int result; + if (!apic->isr_count) + return -1; + if (likely(apic->highest_isr_cache != -1)) + return apic->highest_isr_cache; result = find_highest_vector(apic->regs + APIC_ISR); ASSERT(result == -1 || result >= 16); @@ -492,7 +537,7 @@ static void apic_set_eoi(struct kvm_lapic *apic) if (vector == -1) return; - apic_clear_vector(vector, apic->regs + APIC_ISR); + apic_clear_isr(vector, apic); apic_update_ppr(apic); if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI) && @@ -1081,6 +1126,8 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu) apic_set_reg(apic, APIC_TMR + 0x10 * i, 0); } apic->irr_pending = false; + apic->isr_count = 0; + apic->highest_isr_cache = -1; update_divide_count(apic); atomic_set(&apic->lapic_timer.pending, 0); if (kvm_vcpu_is_bsp(vcpu)) @@ -1248,7 +1295,7 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) if (vector == -1) return -1; - apic_set_vector(vector, apic->regs + APIC_ISR); + apic_set_isr(vector, apic); apic_update_ppr(apic); apic_clear_irr(vector, apic); return vector; @@ -1267,6 +1314,8 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu) update_divide_count(apic); start_apic_timer(apic); apic->irr_pending = true; + apic->isr_count = count_vectors(apic->regs + APIC_ISR); + apic->highest_isr_cache = -1; kvm_make_request(KVM_REQ_EVENT, vcpu); } diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index d29da25..5ac9e5e 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -13,6 +13,10 @@ struct kvm_lapic { u32 divide_count; struct kvm_vcpu *vcpu; bool irr_pending; + /* Number of bits set in ISR. */ + s16 isr_count; + /* The highest vector set in ISR; if -1 - invalid, must scan ISR. */ + int highest_isr_cache; /** * APIC register page. The layout matches the register layout seen by * the guest 1:1, because it is accessed by the vmx microcode. |
