diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/lapic.c | 46 | ||||
| -rw-r--r-- | arch/x86/kvm/lapic.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 |
4 files changed, 39 insertions, 10 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 681e23071847..642273712e6a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -920,6 +920,7 @@ struct kvm_arch { atomic_t vapics_in_nmi_mode; struct mutex apic_map_lock; struct kvm_apic_map *apic_map; + bool apic_map_dirty; bool apic_access_page_done; unsigned long apicv_inhibit_reasons; diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 18a42dcab3c6..41bd49ebe355 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -164,14 +164,28 @@ static void kvm_apic_map_free(struct rcu_head *rcu) kvfree(map); } -static void recalculate_apic_map(struct kvm *kvm) +void kvm_recalculate_apic_map(struct kvm *kvm) { struct kvm_apic_map *new, *old = NULL; struct kvm_vcpu *vcpu; int i; u32 max_id = 255; /* enough space for any xAPIC ID */ + if (!kvm->arch.apic_map_dirty) { + /* + * Read kvm->arch.apic_map_dirty before + * kvm->arch.apic_map + */ + smp_rmb(); + return; + } + mutex_lock(&kvm->arch.apic_map_lock); + if (!kvm->arch.apic_map_dirty) { + /* Someone else has updated the map. */ + mutex_unlock(&kvm->arch.apic_map_lock); + return; + } kvm_for_each_vcpu(i, vcpu, kvm) if (kvm_apic_present(vcpu)) @@ -236,6 +250,12 @@ out: old = rcu_dereference_protected(kvm->arch.apic_map, lockdep_is_held(&kvm->arch.apic_map_lock)); rcu_assign_pointer(kvm->arch.apic_map, new); + /* + * Write kvm->arch.apic_map before + * clearing apic->apic_map_dirty + */ + smp_wmb(); + kvm->arch.apic_map_dirty = false; mutex_unlock(&kvm->arch.apic_map_lock); if (old) @@ -257,20 +277,20 @@ static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val) else static_key_slow_inc(&apic_sw_disabled.key); - recalculate_apic_map(apic->vcpu->kvm); + apic->vcpu->kvm->arch.apic_map_dirty = true; } } static inline void kvm_apic_set_xapic_id(struct kvm_lapic *apic, u8 id) { kvm_lapic_set_reg(apic, APIC_ID, id << 24); - recalculate_apic_map(apic->vcpu->kvm); + apic->vcpu->kvm->arch.apic_map_dirty = true; } static inline void kvm_apic_set_ldr(struct kvm_lapic *apic, u32 id) { kvm_lapic_set_reg(apic, APIC_LDR, id); - recalculate_apic_map(apic->vcpu->kvm); + apic->vcpu->kvm->arch.apic_map_dirty = true; } static inline u32 kvm_apic_calc_x2apic_ldr(u32 id) @@ -286,7 +306,7 @@ static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u32 id) kvm_lapic_set_reg(apic, APIC_ID, id); kvm_lapic_set_reg(apic, APIC_LDR, ldr); - recalculate_apic_map(apic->vcpu->kvm); + apic->vcpu->kvm->arch.apic_map_dirty = true; } static inline int apic_lvt_enabled(struct kvm_lapic *apic, int lvt_type) @@ -1906,7 +1926,7 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) case APIC_DFR: if (!apic_x2apic_mode(apic)) { kvm_lapic_set_reg(apic, APIC_DFR, val | 0x0FFFFFFF); - recalculate_apic_map(apic->vcpu->kvm); + apic->vcpu->kvm->arch.apic_map_dirty = true; } else ret = 1; break; @@ -2012,6 +2032,8 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) break; } + kvm_recalculate_apic_map(apic->vcpu->kvm); + return ret; } EXPORT_SYMBOL_GPL(kvm_lapic_reg_write); @@ -2160,7 +2182,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) static_key_slow_dec_deferred(&apic_hw_disabled); } else { static_key_slow_inc(&apic_hw_disabled.key); - recalculate_apic_map(vcpu->kvm); + vcpu->kvm->arch.apic_map_dirty = true; } } @@ -2201,6 +2223,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) if (!apic) return; + vcpu->kvm->arch.apic_map_dirty = false; /* Stop the timer in case it's a reset to an active apic */ hrtimer_cancel(&apic->lapic_timer.timer); @@ -2252,6 +2275,8 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) vcpu->arch.apic_arb_prio = 0; vcpu->arch.apic_attention = 0; + + kvm_recalculate_apic_map(vcpu->kvm); } /* @@ -2473,17 +2498,18 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) struct kvm_lapic *apic = vcpu->arch.apic; int r; - kvm_lapic_set_base(vcpu, vcpu->arch.apic_base); /* set SPIV separately to get count of SW disabled APICs right */ apic_set_spiv(apic, *((u32 *)(s->regs + APIC_SPIV))); r = kvm_apic_state_fixup(vcpu, s, true); - if (r) + if (r) { + kvm_recalculate_apic_map(vcpu->kvm); return r; + } memcpy(vcpu->arch.apic->regs, s->regs, sizeof(*s)); - recalculate_apic_map(vcpu->kvm); + kvm_recalculate_apic_map(vcpu->kvm); kvm_apic_set_version(vcpu); apic_update_ppr(apic); diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index ec6fbfe325cf..7581bc2dcd47 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -78,6 +78,7 @@ void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8); void kvm_lapic_set_eoi(struct kvm_vcpu *vcpu); void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value); u64 kvm_lapic_get_base(struct kvm_vcpu *vcpu); +void kvm_recalculate_apic_map(struct kvm *kvm); void kvm_apic_set_version(struct kvm_vcpu *vcpu); int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val); int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 864d0aded0b8..c5762c031b0c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -350,6 +350,7 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info) } kvm_lapic_set_base(vcpu, msr_info->data); + kvm_recalculate_apic_map(vcpu->kvm); return 0; } EXPORT_SYMBOL_GPL(kvm_set_apic_base); |