Re: [PATCH 6/7] KVM: selftests: Expose the primary memslot number to tests

[Sean Christopherson <sean.j.christopherson@intel.com>]

On Mon, Mar 23, 2020 at 03:12:02PM -0400, Peter Xu wrote:
> On Fri, Mar 20, 2020 at 01:55:45PM -0700, Sean Christopherson wrote:
> > Add a define for the primary memslot number so that tests can manipulate
> > the memslot, e.g. to delete it.
> > 
> > Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> > ---
> >  tools/testing/selftests/kvm/include/kvm_util.h | 2 ++
> >  tools/testing/selftests/kvm/lib/kvm_util.c     | 4 ++--
> >  2 files changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> > index 0f0e86e188c4..43b5feb546c6 100644
> > --- a/tools/testing/selftests/kvm/include/kvm_util.h
> > +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> > @@ -60,6 +60,8 @@ enum vm_mem_backing_src_type {
> >  	VM_MEM_SRC_ANONYMOUS_HUGETLB,
> >  };
> >  
> > +#define VM_PRIMARY_MEM_SLOT	0
> > +
> >  int kvm_check_cap(long cap);
> >  int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap);
> >  
> > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> > index f69fa84c9a4c..6a1af0455e44 100644
> > --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> > @@ -247,8 +247,8 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
> >  	/* Allocate and setup memory for guest. */
> >  	vm->vpages_mapped = sparsebit_alloc();
> >  	if (phy_pages != 0)
> > -		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
> > -					    0, 0, phy_pages, 0);
> > +		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, 0,
> > +					    VM_PRIMARY_MEM_SLOT, phy_pages, 0);
> 
> IIUC VM_PRIMARY_MEM_SLOT should be used more than here... E.g., to all
> the places that allocate page tables in virt_map() as the last param?
> I didn't check other places.

Ouch, yeah, it bleeds into vm_vaddr_alloc() as well.
 
> Maybe it's simpler to drop this patch for now and use 0 directly as
> before for now, after all in the last patch the comment is good enough
> for me to understand slot 0 is the default slot.

Ya, I'll drop this and hardcode '0', it's a rather absurd amount of call
sites to change.