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

Dor Laor
2011-08-04T08:37:29Z

On 08/03/2011 05:24 PM, 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.

While this will cover the case were the host stops a guest, there will
be other plain cases where the host is just over committed and will
cause a softlockup false positive on the guest.

Softlockup should use stolen time that makes use of the guest running
info would cover both cases

>
> 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.
>
> Eric B Munson (3):
> Add flag to indicate that a vm was stopped by the host
> Add functions to check if the host has stopped the vm
> Add check for suspended vm in softlockup detector
>
> arch/x86/include/asm/pvclock-abi.h | 1 +
> arch/x86/include/asm/pvclock.h | 3 +++
> arch/x86/kernel/kvmclock.c | 12 ++++++++++++
> kernel/watchdog.c | 11 +++++++++++
> 4 files changed, 27 insertions(+), 0 deletions(-)
>