问题
When I run "cat /proc/interrupts", I can get the following:
CPU0 CPU1
0: 253 1878 IO-APIC-edge timer
1: 3 0 IO-APIC-edge i8042
7: 1 0 IO-APIC-edge parport0
8: 0 1 IO-APIC-edge rtc0
9: 0 0 IO-APIC-fasteoi acpi
12: 1 3 IO-APIC-edge i8042
16: 681584 60 IO-APIC-fasteoi uhci_hcd:usb3, nvidia
17: 0 0 IO-APIC-fasteoi uhci_hcd:usb4, uhci_hcd:usb7
18: 0 0 IO-APIC-fasteoi uhci_hcd:usb8
22: 2 1 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb5
23: 17 17 IO-APIC-fasteoi ehci_hcd:usb2, uhci_hcd:usb6
44: 146232 472747 PCI-MSI-edge ahci
45: 118 115 PCI-MSI-edge snd_hda_intel
46: 10038650 842 PCI-MSI-edge eth1
NMI: 44479 43798 Non-maskable interrupts
LOC: 19025635 29426776 Local timer interrupts
SPU: 0 0 Spurious interrupts
PMI: 44479 43798 Performance monitoring interrupts
IWI: 0 0 IRQ work interrupts
RES: 3442001789 3442627214 Rescheduling interrupts
CAL: 1406 1438 Function call interrupts
TLB: 781318 792403 TLB shootdowns
TRM: 0 0 Thermal event interrupts
THR: 0 0 Threshold APIC interrupts
MCE: 0 0 Machine check exceptions
MCP: 2063 2063 Machine check polls
ERR: 0
MIS: 0
How can I get the interrupt number of "NMI" "LOC" "SPU" "PMI", etc.
回答1:
On x86 NMIs are always on interrupt vector 2. The number is hard-coded just as common exceptions (division by 0, page fault, etc). You can find this in the CPU documentation from Intel/AMD.
If the APIC is enabled (as is the case in the dump presented in the question), Spurious Interrupt's interrupt vector number can be obtained from APIC's SVR register. Again, see the same CPU documentation on that.
If the APIC isn't enabled and instead the PIC is being used, then Spurious Interrupts are delivered as IRQ7 (see the 8259A PIC chip spec for that). The BIOS programs the PIC in such a way that IRQ7 is interrupt vector 0Fh, but Windows and Linux change this mapping to avoid sharing the same interrupt vectors for IRQs and CPU exceptions. It seems like this mapping can't be queried from the PIC, but it's established via sending the Initialization Control Word 2 (ICW2) to the PIC. Here's the relevant piece of Linux code in init_8259A():
/* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64,
to 0x20-0x27 on i386 */
outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR);
That should answer the Spurious Interrupt vector part.
As for LOC and PMI, I think, these are local APIC's interrupts and you can find their interrupt vectors from the APIC just like with the Spurious Interrupt above.
来源：https://stackoverflow.com/questions/11379668/how-to-get-the-interrupt-vector