On Thu, 01 Dec 2011, Jan Kiszka wrote: > On 2011-11-29 22:36, Eric B Munson wrote: > > Often when a guest is stopped from the qemu console, it will report spurious > > soft lockup warnings on resume. There are kernel patches being discussed > > that > > will give the host the ability to tell the guest that it is being stopped > > and > > should ignore the soft lockup warning that generates. > > > > Signed-off-by: Eric B Munson <[email protected]> > > Cc: [email protected] > > Cc: [email protected] > > Cc: [email protected] > > Cc: [email protected] > > Cc: [email protected] > > Cc: [email protected] > > --- > > target-i386/kvm.c | 6 ++++++ > > 1 files changed, 6 insertions(+), 0 deletions(-) > > > > diff --git a/target-i386/kvm.c b/target-i386/kvm.c > > index 5bfc21f..defd364 100644 > > --- a/target-i386/kvm.c > > +++ b/target-i386/kvm.c > > @@ -336,12 +336,18 @@ static int kvm_inject_mce_oldstyle(CPUState *env) > > return 0; > > } > > > > +static void kvm_put_guest_paused(CPUState *penv) > > +{ > > + kvm_vcpu_ioctl(penv, KVM_GUEST_PAUSED, 0); > > +} > > I see no need in encapsulating this in a separate function. >
The encapsulated function was from a previous idea, I will remove it for V2.
> > +
> > static void cpu_update_state(void *opaque, int running, RunState state)
> > {
> > CPUState *env = opaque;
> >
> > if (running) {
> > env->tsc_valid = false;
> > + kvm_put_guest_paused(env);
>
> checkpatch.pl would have asked you to remove this tab.
Will change to spaces for V2.
>
> More general:
>
> Why is this x86-only? If the kernel interface is x86-only, what prevents
> making it generic right from the beginning?
>
> Why do we need a new IOCTL for this? Was there no space left in the
> kvm_run structure e.g. to pass this flag down on next vcpu execution? No
> big deal, just wondering.
Thanks for your review/feedback.
When I started looking into this problem, the ioctl was the first suggestion I
got for how to communicate from qemu to guest kernel. I don't see a technical
reason that this could not be added to the kvm_run structure in one of the
bytes currently used as padding. I would prefer to keep the ioctl because I
have the corresponding kernel patches out to work with this, however, if there
is a strong preference for using kvm_run, I can rework both sets.
Eric
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