Re: [RFC PATCH 0/3] Avoid soft lockup message when KVM is stopped by

Marcelo Tosatti <[email protected]> Thu, 04 Aug 2011 16:29:02 +0000
Newsgroups org.kernel.vger.kvm-ia64,org.kernel.vger.kvm,org.kernel.vger.kvm-ppc,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On Wed, Aug 03, 2011 at 10:24:58AM -0400, Eric B Munson wrote:
> This set is just a rough first pass at avoiding soft lockup warnings when a host
> pauses the execution of a guest.  A flag is set by the host in the shared page
> used for the pvclock when the host goes to stop the guest.  When the guest
> resumes and detects a soft lockup, this flag is checked and cleared and the soft
> lockup message is skipped.
> 
> This currently breaks the build for non-x86 architectures but part of what I am
> looking for here is how to go about adding the function stubs for everything
> else.

To fix this, you can save/restore the offset added to kvmclock on
vmstop/vmstart. See hw/kvmclock.c in the qemu source tree.