Even though there is a delivery mode field at the entries of an IO APIC's
redirection table, the documentation of the majority of the IO APICs
explicitly states that interrupt delivery as non-maskable is not supported.
Thus,
However, when using an IO APIC in combination with the Intel VT-d interrupt
remapping functionality, the delivery of the interrupt to the CPU is
handled by the remapping hardware. In such a case, the interrupt can be
delivered as non maskable.
Thus, add the IRQCHIP_CAN_DELIVER_AS_NMI flag only when used in combination
with interrupt remapping.
Cc: Ashok Raj <ashok....@intel.com>
Cc: Andi Kleen <andi.kl...@intel.com>
Cc: Tony Luck <tony.l...@intel.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: Jacob Pan <jacob.jun....@intel.com>
Cc: Juergen Gross <jgr...@suse.com>
Cc: Baoquan He <b...@redhat.com>
Cc: "Eric W. Biederman" <ebied...@xmission.com>
Cc: Dou Liyang <douly.f...@cn.fujitsu.com>
Cc: Jan Kiszka <jan.kis...@siemens.com>
Cc: "Ravi V. Shankar" <ravi.v.shan...@intel.com>
Cc: x...@kernel.org
Cc: io...@lists.linux-foundation.org
Signed-off-by: Ricardo Neri <ricardo.neri-calde...@linux.intel.com>
---
arch/x86/kernel/apic/io_apic.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 10a20f8..39de91b 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1911,7 +1911,8 @@ static struct irq_chip ioapic_ir_chip __read_mostly = {
.irq_eoi = ioapic_ir_ack_level,
.irq_set_affinity = ioapic_set_affinity,
.irq_retrigger = irq_chip_retrigger_hierarchy,
- .flags = IRQCHIP_SKIP_SET_WAKE,
+ .flags = IRQCHIP_SKIP_SET_WAKE |
+ IRQCHIP_CAN_DELIVER_AS_NMI,
};
static inline void init_IO_APIC_traps(void)
--
2.7.4
