On Sun, Feb 17, 2013 at 02:46:28AM +0000, zhangzhi wrote: > I have been studying some stuff about KVM and sincerely hope that someone is > willing to reply to this mail. > As we know, If physical NIC interrupt is received on physical CPU 0 which is in > root mode and the hypervisor determines that this is a network packet targeted > to the emulated NIC for a VM at the same time this VM is running a user program > in guest mode on physical CPU 1. > My question is: > At this time can hypervisor running on CPU 0 *actively* interrupt VM and make it > run the corresponding interrupt handler to handle the incoming network data > packet? CPU 1 which is running a user program is not supposed to vm-exit > considering the performance effect, so I can not use the inter-processor > interrupt(IPI) to cause the CPU1 to leave guest mode and exit to the hypervisor. > With current generation of CPUs you will have to use IPI to make CPU1 vmexit and inject interrupt on the next vmentry. Future CPU will allow to inject interrupt into a running guest without vmexit. On Intel this is called "posted interrupts". -- Gleb. -- 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
