tree 3a87b9355b9fce43838e803a38591bb0e4bb908e
parent a94820ddc36f8c452b37f9dcb323f55ffdbc75f9
author Jan Kiszka <jan.kiszka@siemens.com> 1341844952 +0200
committer Avi Kivity <avi@redhat.com> 1341909069 +0300

apic: Defer interrupt updates to VCPU thread

KVM performs TPR raising asynchronously to QEMU, specifically outside
QEMU's global lock. When an interrupt is injected into the APIC and TPR
is checked to decide if this can be delivered, a stale TPR value may be
used, causing spurious interrupts in the end.

Fix this by deferring apic_update_irq to the context of the target VCPU.
We introduce a new interrupt flag for this, CPU_INTERRUPT_POLL. When it
is set, the VCPU calls apic_poll_irq before checking for further pending
interrupts. To avoid special-casing KVM, we also implement this logic
for TCG mode.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>