Il 10/03/2013 19:10, Gleb Natapov ha scritto: > On Sun, Mar 10, 2013 at 06:19:07PM +0100, Paolo Bonzini wrote: >> Il 10/03/2013 16:35, Gleb Natapov ha scritto: >>>>> However, it would effectively redefine the meaning of >>>>> KVM_MP_STATE_INIT_RECEIVED and KVM_MP_STATE_SIPI_RECEIVED, respectively >>>>> to KVM_MP_STATE_WAIT_FOR_SIPI and KVM_MP_STATE_RESETTING. I wasn't sure >>>>> if this is considered an API change (personally, I would treat it as one). >>>>> >>> If it is kernel module internal it definitely is not API change. >>> INIT/SIPI handling is a bit ad-hoc right now anyway as Jan noticed. For >>> instance INIT does not really resets VCPU. Only after SIPI it is really >>> reset, so KVM_MP_STATE_SIPI_RECEIVED is really KVM_MP_STATE_RESET_ME_RIGHT_NOW >>> state. >> >> Yeah, and the current definition is ambiguous (without hypervisor >> patches, there's no way to use it as the names would suggest), so >> perhaps the right thing to do is to rename the states (old names kept >> for backwards compatibility only) and work from there. >> > I do not see how renaming clarify things. From userspace point of view > KVM_MP_STATE_SIPI_RECEIVED does not exists. Not really true---we do exit with that state and EINTR when we get a SIPI. Perhaps that can be changed. > If AP is hard reset > userspase makes it UNINIT, if soft reset it makes it INIT_RECEIVED, if > BSP it makes it running no matter what type of reset. The current name just suggests . And when getting an INIT in the in-kernel LAPIC, this: - vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED; + vcpu->arch.mp_state = kvm_vcpu_is_bsp(vcpu) ? + KVM_MP_STATE_SIPI_RECEIVED : + KVM_MP_STATE_INIT_RECEIVED; makes much less sense than this: - vcpu->arch.mp_state = KVM_MP_STATE_WAIT_FOR_SIPI; + vcpu->arch.mp_state = kvm_vcpu_is_bsp(vcpu) ? + KVM_MP_STATE_RESET_NOW : + KVM_MP_STATE_WAIT_FOR_SIPI; However, there's also Jan's plans for nVMX. Peeking at his queue (see http://git.kiszka.org/?p=linux-kvm.git;a=commitdiff;h=037fb24ec) I think it's better to always reflect INITs to the hypervisor like I did in these patches. Paolo -- 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
