On Sun, Oct 13, 2013 at 11:48:03AM +0300, Gleb Natapov wrote:
> On Tue, Oct 08, 2013 at 04:54:58PM +0200, Christian Borntraeger wrote:
> > From: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
> >
> > kvm_clear_async_pf_completion get an additional flag to either cancel outstanding
> > work or wait for oustanding work to be finished, x86 currentlx cancels all work.
> >
> I do not see why x86 would not cancel all work in the feature, so the
> flag seems to be always true on s390 and always false on x86, which
> means that it is better to make it compile time option, same as
> KVM_ASYNC_PF_SYNC. Actually we can reuse KVM_ASYNC_PF_SYNC in
> kvm_clear_async_pf_completion_queue() instead of adding another one.
>
Spoke to soon. I see that s390 uses both true and false, mostly false.
Lets add another function kvm_drain_async_pf_completion_queue() instead
of new parameter.
> > Signed-off-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
> > ---
> > arch/x86/kvm/x86.c | 8 ++++----
> > include/linux/kvm_host.h | 2 +-
> > virt/kvm/async_pf.c | 6 +++++-
> > 3 files changed, 10 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > index 187f824..00a4262 100644
> > --- a/arch/x86/kvm/x86.c
> > +++ b/arch/x86/kvm/x86.c
> > @@ -539,7 +539,7 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
> > kvm_x86_ops->set_cr0(vcpu, cr0);
> >
> > if ((cr0 ^ old_cr0) & X86_CR0_PG) {
> > - kvm_clear_async_pf_completion_queue(vcpu);
> > + kvm_clear_async_pf_completion_queue(vcpu, false);
> > kvm_async_pf_hash_reset(vcpu);
> > }
> >
> > @@ -1911,7 +1911,7 @@ static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
> > vcpu->arch.apf.msr_val = data;
> >
> > if (!(data & KVM_ASYNC_PF_ENABLED)) {
> > - kvm_clear_async_pf_completion_queue(vcpu);
> > + kvm_clear_async_pf_completion_queue(vcpu, false);
> > kvm_async_pf_hash_reset(vcpu);
> > return 0;
> > }
> > @@ -6742,7 +6742,7 @@ void kvm_vcpu_reset(struct kvm_vcpu *vcpu)
> >
> > kvmclock_reset(vcpu);
> >
> > - kvm_clear_async_pf_completion_queue(vcpu);
> > + kvm_clear_async_pf_completion_queue(vcpu, false);
> > kvm_async_pf_hash_reset(vcpu);
> > vcpu->arch.apf.halted = false;
> >
> > @@ -7015,7 +7015,7 @@ static void kvm_free_vcpus(struct kvm *kvm)
> > * Unpin any mmu pages first.
> > */
> > kvm_for_each_vcpu(i, vcpu, kvm) {
> > - kvm_clear_async_pf_completion_queue(vcpu);
> > + kvm_clear_async_pf_completion_queue(vcpu, false);
> > kvm_unload_vcpu_mmu(vcpu);
> > }
> > kvm_for_each_vcpu(i, vcpu, kvm)
> > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > index b4e8666..223fcf3 100644
> > --- a/include/linux/kvm_host.h
> > +++ b/include/linux/kvm_host.h
> > @@ -192,7 +192,7 @@ struct kvm_async_pf {
> > struct page *page;
> > };
> >
> > -void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu);
> > +void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu, bool flush);
> > void kvm_check_async_pf_completion(struct kvm_vcpu *vcpu);
> > int kvm_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, unsigned long hva,
> > struct kvm_arch_async_pf *arch);
> > diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
> > index 8f57d63..3e13a73 100644
> > --- a/virt/kvm/async_pf.c
> > +++ b/virt/kvm/async_pf.c
> > @@ -107,7 +107,7 @@ static void async_pf_execute(struct work_struct *work)
> > kvm_put_kvm(vcpu->kvm);
> > }
> >
> > -void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
> > +void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu, bool flush)
> > {
> > /* cancel outstanding work queue item */
> > while (!list_empty(&vcpu->async_pf.queue)) {
> > @@ -115,6 +115,10 @@ void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
> > list_entry(vcpu->async_pf.queue.next,
> > typeof(*work), queue);
> > list_del(&work->queue);
> > + if (flush) {
> > + flush_work(&work->work);
> > + continue;
> > + }
> > if (cancel_work_sync(&work->work)) {
> > mmdrop(work->mm);
> > kvm_put_kvm(vcpu->kvm); /* == work->vcpu->kvm */
> > --
> > 1.8.3.1
>
> --
> Gleb.
> --
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--
Gleb.
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