From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH v5 2/5] KVM: VMX: Register a new IPI for posted interrupt Date: Fri, 8 Mar 2013 15:47:19 +0200 Message-ID: <20130308134719.GH24444@redhat.com> References: <1362705801-4467-1-git-send-email-yang.z.zhang@intel.com> <1362705801-4467-3-git-send-email-yang.z.zhang@intel.com> <20130308132625.GA27750@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Yang Zhang , kvm@vger.kernel.org, mtosatti@redhat.com, xiantao.zhang@intel.com, hpa@linux.intel.com To: Ingo Molnar Return-path: Received: from mx1.redhat.com ([209.132.183.28]:12333 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933538Ab3CHNra (ORCPT ); Fri, 8 Mar 2013 08:47:30 -0500 Content-Disposition: inline In-Reply-To: <20130308132625.GA27750@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Mar 08, 2013 at 02:26:25PM +0100, Ingo Molnar wrote: > > * Yang Zhang wrote: > > > diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c > > index 6e03b0d..2329a54 100644 > > --- a/arch/x86/kernel/irqinit.c > > +++ b/arch/x86/kernel/irqinit.c > > @@ -205,6 +205,10 @@ static void __init apic_intr_init(void) > > > > /* IPI for X86 platform specific use */ > > alloc_intr_gate(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi); > > +#ifdef CONFIG_HAVE_KVM > > + /* IPI for KVM to deliver posted interrupt */ > > + alloc_intr_gate(POSTED_INTR_VECTOR, kvm_posted_intr_ipi); > > +#endif > > Please avoid wasting an IDT entry by reusing x86_platform_ipi. > > A KVM guest is in essence one type of 'x86 platform', and this callback is used by > hardware platforms, so collision is not an issue AFAICS. > This is IPI send by a host though. -- Gleb.