Hi Guys, I am writing very simple bios for KVM (not using Qemu but creating a simple io device models around KVM). I am having trouble in receiving regular Timer interrupts after programming PIT. I think I have enabled PIC and PIT correctly using following code:- PIC Programming ;; PIC mov al, #0x00 out 0x21, AL ;master pic: all IRQs unmasked out 0xA1, AL ;slave pic: all IRQs unmasked PIT Programming and also enable PIT to genrate regular timer interruput SET_INT_VECTOR(0x08, #0xF000, #int08_handler) mov al, #0x34 ; timer0: binary count, 16bit count, mode 2 out 0x43, al mov al, #0x00 ; maximum count of 0000H = 18.2Hz out 0x40, al out 0x40, al PIT Timer ISR code Timer ISR code ;--------- ;- INT08 - ;--------- .org 0xfea5 ; INT 08h System Timer ISR Entry Point int08_handler: sti push ax push ds mov ax, #0x0040 mov ds, ax mov ax, 0x006c ; increment lower word inc ax mov 0x006c, ax jnz inc_done mov ax, 0x006e ; increment upper word inc ax mov 0x006e, ax For some reason I never see int08_handler ever been called. Any clues what may be wrong? I am creating only one VCPU -Abhishek -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html