On Wed, 16 Jul 2025 at 12:02, Xiaoyao Li <xiaoyao.li@xxxxxxxxx> wrote:
>
> On 7/16/2025 6:25 PM, David Hildenbrand wrote:
> > On 16.07.25 10:31, Xiaoyao Li wrote:
> >> On 7/16/2025 4:11 PM, Fuad Tabba wrote:
> >>> On Wed, 16 Jul 2025 at 05:09, Xiaoyao Li<xiaoyao.li@xxxxxxxxx> wrote:
> >>>> On 7/15/2025 5:33 PM, Fuad Tabba wrote:
> >>>>> The original name was vague regarding its functionality. This Kconfig
> >>>>> option specifically enables and gates the kvm_gmem_populate()
> >>>>> function,
> >>>>> which is responsible for populating a GPA range with guest data.
> >>>> Well, I disagree.
> >>>>
> >>>> The config KVM_GENERIC_PRIVATE_MEM was introduced by commit
> >>>> 89ea60c2c7b5
> >>>> ("KVM: x86: Add support for "protected VMs" that can utilize private
> >>>> memory"), which is a convenient config for vm types that requires
> >>>> private memory support, e.g., SNP, TDX, and KVM_X86_SW_PROTECTED_VM.
> >>>>
> >>>> It was commit e4ee54479273 ("KVM: guest_memfd: let kvm_gmem_populate()
> >>>> operate only on private gfns") that started to use
> >>>> CONFIG_KVM_GENERIC_PRIVATE_MEM gates kvm_gmem_populate() function. But
> >>>> CONFIG_KVM_GENERIC_PRIVATE_MEM is not for kvm_gmem_populate() only.
> >>>>
> >>>> If using CONFIG_KVM_GENERIC_PRIVATE_MEM to gate kvm_gmem_populate() is
> >>>> vague and confusing, we can introduce KVM_GENERIC_GMEM_POPULATE to gate
> >>>> kvm_gmem_populate() and select KVM_GENERIC_GMEM_POPULATE under
> >>>> CONFIG_KVM_GENERIC_PRIVATE_MEM.
> >>>>
> >>>> Directly replace CONFIG_KVM_GENERIC_PRIVATE_MEM with
> >>>> KVM_GENERIC_GMEM_POPULATE doesn't look correct to me.
> >>> I'll quote David's reply to an earlier version of this patch [*]:
> >>
> >> It's not related to my concern.
> >>
> >> My point is that CONFIG_KVM_GENERIC_PRIVATE_MEM is used for selecting
> >> the private memory support. Rename it to KVM_GENERIC_GMEM_POPULATE is
> >> not correct.
> >
> > It protects a function that is called kvm_gmem_populate().
> >
> > Can we stop the nitpicking?
>
> I don't think it's nitpicking.
>
> Could you loot into why it was named as KVM_GENERIC_PRIVATE_MEM in the
> first place, and why it was picked to protect kvm_gmem_populate()?
That is, in part, the point of this patch. This flag protects
kvm_gmem_populate(), and the name didn't reflect that. Now it does. It
is the only thing it protects.
Cheers,
/fuad
