diff options
author | Jan Kiszka <jan.kiszka@siemens.com> | 2012-07-09 16:42:30 +0200 |
---|---|---|
committer | Michael Roth <mdroth@linux.vnet.ibm.com> | 2012-08-21 15:36:35 -0500 |
commit | c337db8cc9f4725c0654134de42b97f7847186a4 (patch) | |
tree | f58dfa18aae842022426342058e3da245ebf8e27 | |
parent | 44a42fd2b69b1bc9cdb54d0cbfcdfd6b3bbf0c31 (diff) |
apic: Resolve potential endless loop around apic_update_irq
Commit d96e173769 refactored the reinjection of pending PIC interrupts.
However, it missed the potential loop of apic_update_irq ->
apic_deliver_pic_intr -> apic_local_deliver -> apic_set_irq ->
apic_update_irq that /could/ occur if LINT0 is injected as APIC_DM_FIXED
and that vector is currently blocked via TPR.
Resolve this by reinjecting only where it matters: inside
apic_get_interrupt. This function may clear a vector while a
PIC-originated reason still exists.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
(cherry picked from commit 3db3659bf60094657e1465cc809acb09551816ee)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
-rw-r--r-- | hw/apic.c | 10 |
1 files changed, 7 insertions, 3 deletions
@@ -371,9 +371,6 @@ static void apic_update_irq(APICCommonState *s) } if (apic_irq_pending(s) > 0) { cpu_interrupt(s->cpu_env, CPU_INTERRUPT_HARD); - } else if (apic_accept_pic_intr(&s->busdev.qdev) && - pic_get_output(isa_pic)) { - apic_deliver_pic_intr(&s->busdev.qdev, 1); } } @@ -568,7 +565,14 @@ int apic_get_interrupt(DeviceState *d) reset_bit(s->irr, intno); set_bit(s->isr, intno); apic_sync_vapic(s, SYNC_TO_VAPIC); + + /* re-inject if there is still a pending PIC interrupt */ + if (apic_accept_pic_intr(&s->busdev.qdev) && pic_get_output(isa_pic)) { + apic_deliver_pic_intr(&s->busdev.qdev, 1); + } + apic_update_irq(s); + return intno; } |