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 <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Tony Luck <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Jacob Pan <[email protected]> Cc: Juergen Gross <[email protected]> Cc: Baoquan He <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Cc: Dou Liyang <[email protected]> Cc: Jan Kiszka <[email protected]> Cc: "Ravi V. Shankar" <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Ricardo Neri <[email protected]> --- 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 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
