From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964875Ab2CBWYY (ORCPT ); Fri, 2 Mar 2012 17:24:24 -0500 Received: from oz.csail.mit.edu ([128.30.30.239]:48555 "EHLO mail.mgebm.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757646Ab2CBWYT (ORCPT ); Fri, 2 Mar 2012 17:24:19 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Date: Fri, 02 Mar 2012 14:23:55 -0800 From: Eric B Munson To: Cc: , , , , , , , , Subject: Re: [PATCH 0/4 V15] Avoid soft lockup message when KVM is stopped by host In-Reply-To: <1329704577-6329-1-git-send-email-emunson@mgebm.net> References: <1329704577-6329-1-git-send-email-emunson@mgebm.net> Message-ID: User-Agent: Roundcube Webmail/0.5.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 19 Feb 2012 21:22:53 -0500, Eric B Munson wrote: > Changes from V14: > Update documentation for the pvclock api ... snip > > When a guest kernel is stopped by the host hypervisor it can look > like a soft > lockup to the guest kernel. This false warning can mask later soft > lockup > warnings which may be real. This patch series adds a method for a > host > hypervisor to communicate to a guest kernel that it is being stopped. > The > final patch in the series has the watchdog check this flag when it > goes to > issue a soft lockup warning and skip the warning if the guest knows > it was > stopped. > > It was attempted to solve this in Qemu, but the side effects of > saving and > restoring the clock and tsc for each vcpu put the wall clock of the > guest behind > by the amount of time of the pause. This forces a guest to have ntp > running > in order to keep the wall clock accurate. Avi, Is this version acceptable for merging? I'd really like this to go in for the 3.4 merge window. Thanks, Eric > > Cc: mingo@redhat.com > Cc: hpa@zytor.com > Cc: ryanh@linux.vnet.ibm.com > Cc: aliguori@us.ibm.com > Cc: mtosatti@redhat.com > Cc: kvm@vger.kernel.org > Cc: linux-arch@vger.kernel.org > Cc: x86@kernel.org > Cc: linux-kernel@vger.kernel.org > > Eric B Munson (4): > Add flag to indicate that a vm was stopped by the host > Add functions to check if the host has stopped the vm > Add ioctl for KVM_KVMCLOCK_CTRL > Add check for suspended vm in softlockup detector > > Documentation/virtual/kvm/api.txt | 20 ++++++++++++++++++++ > Documentation/virtual/kvm/msr.txt | 4 ++++ > arch/ia64/include/asm/kvm_para.h | 5 +++++ > arch/powerpc/include/asm/kvm_para.h | 5 +++++ > arch/s390/include/asm/kvm_para.h | 5 +++++ > arch/x86/include/asm/kvm_para.h | 8 ++++++++ > arch/x86/include/asm/pvclock-abi.h | 1 + > arch/x86/kernel/kvmclock.c | 21 +++++++++++++++++++++ > arch/x86/kvm/x86.c | 22 ++++++++++++++++++++++ > include/asm-generic/kvm_para.h | 14 ++++++++++++++ > include/linux/kvm.h | 3 +++ > kernel/watchdog.c | 12 ++++++++++++ > 12 files changed, 120 insertions(+), 0 deletions(-) > create mode 100644 include/asm-generic/kvm_para.h