On Wed, Jul 08, 2020 at 03:33:57PM -0400, Peter Xu wrote: > Originally, we have three code paths that can dirty a page without > vcpu context for X86: > > - init_rmode_identity_map > - init_rmode_tss > - kvmgt_rw_gpa > > init_rmode_identity_map and init_rmode_tss will be setup on > destination VM no matter what (and the guest cannot even see them), so > it does not make sense to track them at all. > > To do this, allow __x86_set_memory_region() to return the userspace > address that just allocated to the caller. Then in both of the > functions we directly write to the userspace address instead of > calling kvm_write_*() APIs. > > Another trivial change is that we don't need to explicitly clear the > identity page table root in init_rmode_identity_map() because no > matter what we'll write to the whole page with 4M huge page entries. > > Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> > --- Reviewed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
