diff options
Diffstat (limited to 'arch/x86/kvm/ioapic.c')
| -rw-r--r-- | arch/x86/kvm/ioapic.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 3aab53f8cad2..d380111351c0 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -247,8 +247,7 @@ void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap) index == RTC_GSI) { if (kvm_apic_match_dest(vcpu, NULL, 0, e->fields.dest_id, e->fields.dest_mode) || - (e->fields.trig_mode == IOAPIC_EDGE_TRIG && - kvm_apic_pending_eoi(vcpu, e->fields.vector))) + kvm_apic_pending_eoi(vcpu, e->fields.vector)) __set_bit(e->fields.vector, (unsigned long *)eoi_exit_bitmap); } @@ -269,6 +268,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) { unsigned index; bool mask_before, mask_after; + int old_remote_irr, old_delivery_status; union kvm_ioapic_redirect_entry *e; switch (ioapic->ioregsel) { @@ -291,14 +291,28 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) return; e = &ioapic->redirtbl[index]; mask_before = e->fields.mask; + /* Preserve read-only fields */ + old_remote_irr = e->fields.remote_irr; + old_delivery_status = e->fields.delivery_status; if (ioapic->ioregsel & 1) { e->bits &= 0xffffffff; e->bits |= (u64) val << 32; } else { e->bits &= ~0xffffffffULL; e->bits |= (u32) val; - e->fields.remote_irr = 0; } + e->fields.remote_irr = old_remote_irr; + e->fields.delivery_status = old_delivery_status; + + /* + * Some OSes (Linux, Xen) assume that Remote IRR bit will + * be cleared by IOAPIC hardware when the entry is configured + * as edge-triggered. This behavior is used to simulate an + * explicit EOI on IOAPICs that don't have the EOI register. + */ + if (e->fields.trig_mode == IOAPIC_EDGE_TRIG) + e->fields.remote_irr = 0; + mask_after = e->fields.mask; if (mask_before != mask_after) kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after); |