> -----Original Message----- > From: Marc Zyngier [mailto:marc.zyngier@xxxxxxx] > Sent: Tuesday, January 08, 2013 6:44 PM > To: Sundaram, Senthilkumar > Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: local_irq_disable when Guest is executing > > On 08/01/13 12:03, Sundaram, Senthilkumar wrote: > > I see that in the kvm_arch_vcpu_ioctl_run() function before the guest > starts executing there is a local_irq_disable() and local_irq_enable() after the > guest returns. > > > > What is the motivation for this? Why are we disabling interrupts while the > guest is running? > > You got it slightly wrong. > > Interrupts are disabled while we're doing the world switch. Once we run the > guest, interrupts are redirected to HYP mode. Otherwise, you would simply > kill the host, who needs its interrupts to be serviced no matter what is > running. [[ss]] Thanks, I suspected that IRQs might be routed to Hyp mode, but just wanted to make sure. I have a followup question, Why are the interrupts routed to Hyp Mode? Is it so that there is one unified place to handle all guest exits? Thanks Senthil > > M. > -- > Jazz is not dead. It just smells funny... _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
