KVM: PIC: call ack notifiers for irqs that are dropped form irr

(cherry picked from commit aea218f3cbbcaac249b6b2c98930a00d6d931f1e)

After commit 242ec97c358256 PIT interrupts are no longer delivered after
PIC reset. It happens because PIT injects interrupt only if previous one
was acked, but since on PIC reset it is dropped from irr it will never
be delivered and hence acknowledged. Fix that by calling ack notifier on
PIC reset.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 81cf4fa4a2bea8f35eeb8a68c30bdb3b18564271..0147d165708623c5a54786046eb331132885c3c7 100644 (file)
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -305,6 +305,11 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val)
        addr &= 1;
        if (addr == 0) {
                if (val & 0x10) {
+                       u8 edge_irr = s->irr & ~s->elcr;
+                       int i;
+                       bool found;
+                       struct kvm_vcpu *vcpu;
+
                        s->init4 = val & 1;
                        s->last_irr = 0;
                        s->irr &= s->elcr;
@@ -322,6 +327,18 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val)
                        if (val & 0x08)
                                pr_pic_unimpl(
                                        "level sensitive irq not supported");
+
+                       kvm_for_each_vcpu(i, vcpu, s->pics_state->kvm)
+                               if (kvm_apic_accept_pic_intr(vcpu)) {
+                                       found = true;
+                                       break;
+                               }
+
+
+                       if (found)
+                               for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
+                                       if (edge_irr & (1 << irq))
+                                               pic_clear_isr(s, irq);
                } else if (val & 0x08) {
                        if (val & 0x04)
                                s->poll = 1;