diff options
Diffstat (limited to 'hw/i386/x86-common.c')
| -rw-r--r-- | hw/i386/x86-common.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c index d5a44af243..008496b5b8 100644 --- a/hw/i386/x86-common.c +++ b/hw/i386/x86-common.c @@ -446,8 +446,27 @@ static long get_file_size(FILE *f) void gsi_handler(void *opaque, int n, int level) { GSIState *s = opaque; + bool bypass_ioapic = false; trace_x86_gsi_interrupt(n, level); + +#ifdef CONFIG_XEN_EMU + /* + * Xen delivers the GSI to the Legacy PIC (not that Legacy PIC + * routing actually works properly under Xen). And then to + * *either* the PIRQ handling or the I/OAPIC depending on whether + * the former wants it. + * + * Additionally, this hook allows the Xen event channel GSI to + * work around QEMU's lack of support for shared level interrupts, + * by keeping track of the externally driven state of the pin and + * implementing a logical OR with the state of the evtchn GSI. + */ + if (xen_mode == XEN_EMULATE) { + bypass_ioapic = xen_evtchn_set_gsi(n, &level); + } +#endif + switch (n) { case 0 ... ISA_NUM_IRQS - 1: if (s->i8259_irq[n]) { @@ -456,18 +475,9 @@ void gsi_handler(void *opaque, int n, int level) } /* fall through */ case ISA_NUM_IRQS ... IOAPIC_NUM_PINS - 1: -#ifdef CONFIG_XEN_EMU - /* - * Xen delivers the GSI to the Legacy PIC (not that Legacy PIC - * routing actually works properly under Xen). And then to - * *either* the PIRQ handling or the I/OAPIC depending on - * whether the former wants it. - */ - if (xen_mode == XEN_EMULATE && xen_evtchn_set_gsi(n, level)) { - break; + if (!bypass_ioapic) { + qemu_set_irq(s->ioapic_irq[n], level); } -#endif - qemu_set_irq(s->ioapic_irq[n], level); break; case IO_APIC_SECONDARY_IRQBASE ... IO_APIC_SECONDARY_IRQBASE + IOAPIC_NUM_PINS - 1: |