Re: [Qemu-devel] [PATCH v1 6/7] kvm/x86: Hyper-V SynIC message slot pending clearing at SINT ack

[Andrey Smetanin]

On 11/25/2015 07:52 PM, Paolo Bonzini wrote:
> On 25/11/2015 16:20, Andrey Smetanin wrote:
> > +static void synic_clear_sint_msg_pending(struct kvm_vcpu_hv_synic *synic,
> > +                                       u32 sint)
> > +{
> > +       struct kvm_vcpu *vcpu = synic_to_vcpu(synic);
> > +       struct page *page;
> > +       gpa_t gpa;
> > +       struct hv_message *msg;
> > +       struct hv_message_page *msg_page;
> > +
> > +       gpa = synic->msg_page & PAGE_MASK;
> > +       page = kvm_vcpu_gfn_to_page(vcpu, gpa >> PAGE_SHIFT);
> > +       if (is_error_page(page)) {
> > +               vcpu_err(vcpu, "Hyper-V SynIC can't get msg page, gpa 0x%llx\n",
> > +                        gpa);
> > +               return;
> > +       }
> > +       msg_page = kmap_atomic(page);
>
> But the message page is not being pinned, is it?
Actually I don't know anything about pinning.
Is it pinning against page swapping ?
Could you please clarify and provide an API to use in this case ?
> Paolo
>
> > +       msg = &msg_page->sint_message[sint];
> > +       msg->header.message_flags.msg_pending = 0;
> > +
> > +       kunmap_atomic(msg_page);
> > +       kvm_release_page_dirty(page);
> > +       kvm_vcpu_mark_page_dirty(vcpu, gpa >> PAGE_SHIFT);
> > +}
> > +