From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yong Wang Subject: Re: [PATCH resend v5 6/6] KVM: nVMX: Enable nested posted interrupt processing Date: Sun, 15 Feb 2015 14:27:55 +0800 Message-ID: <20150215062755.GA2603@ywang-linux> References: <1422979097-2203-1-git-send-email-fanwenyi0529@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: pbonzini@redhat.com, gleb@kernel.org, yang.z.zhang@intel.com, wanpeng.li@linux.intel.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jan.kiszka@web.de To: Wincy Van Return-path: Received: from mga14.intel.com ([192.55.52.115]:21572 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769AbbBOG0j (ORCPT ); Sun, 15 Feb 2015 01:26:39 -0500 Content-Disposition: inline In-Reply-To: <1422979097-2203-1-git-send-email-fanwenyi0529@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Feb 03, 2015 at 11:58:17PM +0800, Wincy Van wrote: > If vcpu has a interrupt in vmx non-root mode, we will > kick that vcpu to inject interrupt timely. With posted > interrupt processing, the kick intr is not needed, and > interrupts are fully taken care of by hardware. > > In nested vmx, this feature avoids much more vmexits > than non-nested vmx. > > This patch use L0's POSTED_INTR_NV to avoid unexpected > interrupt if L1's vector is different with L0's. If vcpu > is in hardware's non-root mode, we use a physical ipi to > deliver posted interrupts, otherwise we will accomplish > that posted interrupt in nested vm-entry manually. > > Signed-off-by: Wincy Van > --- > arch/x86/kvm/lapic.c | 13 +++- > arch/x86/kvm/lapic.h | 1 + > arch/x86/kvm/vmx.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++- > 3 files changed, 158 insertions(+), 7 deletions(-) > Wincy, our QA found regressions with this patch that 64bit L2 linux guest fails to boot up when running nested kvm on kvm. Environment: ------------ Host OS (ia32/ia32e/IA64):ia32e Guest OS (ia32/ia32e/IA64):ia32e Guest OS Type (Linux/Windows):Linux kvm.git Commit:6557bada461afeaa920a189fae2cff7c8fdce39f qemu.kvm Commit:5c697ae74170d43928cb185f5ac1a9058adcae0b Host Kernel Version:3.19.0-rc3 Hardware:Ivytown_EP, Haswell_EP Bug detailed description: -------------------------- create 64bit linux guest as L2 guest, the guest boot up fail note: 1. create a 32bit linux guest as L2 guest, the guest boots up fine. 2. create a 64bit windows guest as L2 guest, the guest boots up fine. 3. this should be a kernel bug: kvm + qemu = result 6557bada + 5c697ae7 = bad 8fff5e37 + 5c697ae7 = good Reproduce steps: ---------------- 1 create L1 guest: qemu-system-x86_64 -enable-kvm -m 8G -smp 4 -net nic,macaddr=00:12:31:34:51:31 -net tap,script=/etc/kvm/qemu-ifup nested-kvm.qcow -cpu host 2. create L2 guest qemu-system-x86_64 -enable-kvm -m 2G -smp 2 -net none rhel6u5.qcow Current result: ---------------- create 64bit linux guest as L2 guest, the guest boots up fail Expected result: ---------------- create 64bit linux guest as L2 guest, the guest boots up fine Please take a look. Thanks -Yong