From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amit Shah Subject: Re: [PATCH 0/5 V5] Avoid soft lockup message when KVM is stopped by host Date: Mon, 19 Dec 2011 18:22:17 +0530 Message-ID: <20111219125217.GC3139@amit-x200.redhat.com> References: <1323116344-17911-1-git-send-email-emunson@mgebm.net> <20111208113422.GA27919@amit-x200.redhat.com> <4EE9E023.4000904@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Eric B Munson , mingo@redhat.com, hpa@zytor.com, arnd@arndb.de, ryanh@linux.vnet.ibm.com, aliguori@us.ibm.com, mtosatti@redhat.com, jeremy.fitzhardinge@citrix.com, levinsasha928@gmail.com, Jan Kiszka , kvm@vger.kernel.org, linux-arch@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org To: Avi Kivity Return-path: Content-Disposition: inline In-Reply-To: <4EE9E023.4000904@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On (Thu) 15 Dec 2011 [13:55:15], Avi Kivity wrote: > On 12/08/2011 01:34 PM, Amit Shah wrote: > > On (Mon) 05 Dec 2011 [15:18:59], Eric B Munson wrote: > > > 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. > > > > Guest S4 would need similar treatment, and I think the code in the two > > approaches can be shared. Just something to consider. > > > > Why does S4 need any treatment? The guest is aware that it's sleeping, > unlike the other cases treated here. Er, right. S4 needs some treatment, though, as resume after s4 doesn't work with kvmclock enabled. I didn't realise this series was only handling the soft lockup case. Amit