Re: [RFC PATCH 1/4] KVM: selftests: Add support for creating non-default type VMs

Maxim Levitsky
2021-08-04T14:46:04Z

On Wed, 2021-08-04 at 22:42 +0800, Xiaoyao Li wrote:
> On 8/4/2021 10:24 PM, Maxim Levitsky wrote:
> > On Wed, 2021-08-04 at 14:09 +0800, Xiaoyao Li wrote:
> > > On 7/27/2021 2:37 AM, Erdem Aktas wrote:
> > > > Currently vm_create function only creates KVM_X86_LEGACY_VM type VMs.
> > > > Changing the vm_create function to accept type parameter to create
> > > > new VM types.
> > > >
> > > > Signed-off-by: Erdem Aktas <erdemaktas@google.com>
> > > > Reviewed-by: Sean Christopherson <seanjc@google.com>
> > > > Reviewed-by: Peter Gonda <pgonda@google.com>
> > > > Reviewed-by: Marc Orr <marcorr@google.com>
> > > > Reviewed-by: Sagi Shahar <sagis@google.com>
> > > > ---
> > > > .../testing/selftests/kvm/include/kvm_util.h | 1 +
> > > > tools/testing/selftests/kvm/lib/kvm_util.c | 29 +++++++++++++++++--
> > > > 2 files changed, 27 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
> > > > index d53bfadd2..c63df42d6 100644
> > > > --- a/tools/testing/selftests/kvm/include/kvm_util.h
> > > > +++ b/tools/testing/selftests/kvm/include/kvm_util.h
> > > > @@ -88,6 +88,7 @@ int vcpu_enable_cap(struct kvm_vm *vm, uint32_t vcpu_id,
> > > > void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size);
> > > >
> > > > struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm);
> > > > +struct kvm_vm *__vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm, int type);
> > > > void kvm_vm_free(struct kvm_vm *vmp);
> > > > void kvm_vm_restart(struct kvm_vm *vmp, int perm);
> > > > void kvm_vm_release(struct kvm_vm *vmp);
> > > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> > > > index e5fbf16f7..70caa3882 100644
> > > > --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> > > > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> > > > @@ -180,13 +180,36 @@ _Static_assert(sizeof(vm_guest_mode_params)/sizeof(struct vm_guest_mode_params)
> > > > * Return:
> > > > * Pointer to opaque structure that describes the created VM.
> > > > *
> > > > - * Creates a VM with the mode specified by mode (e.g. VM_MODE_P52V48_4K).
> > > > + * Wrapper VM Create function to create a VM with default type (0).
> > >
> > > Can we pass KVM_X86_LEGACY_VM (whatever name when it's upstreamed)
> > > instead of 0?
> >
> > To be honest I would prefer this to be called something like KVM_X86_STANDARD_VM,
> > or something.
> >
> > I don't think that normal unencrypted virtualization is already legacy, even if TDX
> > docs claim that.
>
> I'm not proposing to use this specific name introduced in TDX RFC
> series, but proposing to use the name defined in KVM in the future
> instead of hard-coded 0.
>
> Yes, KVM_X86_STANDARD_VM or KVM_X86_NORMAL_VM (proposed by Paolo) is
> better than KVM_X86_LEGACY_VM.

KVM_X86_NORMAL_VM is a very good name IMHO as well.
Thanks!

Best regards,
Maxim Levitsky

>
> > Just my personal opinion.
> >
> > Best regards,
> > Maxim Levitsky
> >
> > > > + */
> > > > +struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
> > > > +{
> > > > + return __vm_create(mode, phy_pages, perm, 0);
> > > > +}
> > > > +