Re: [PATCH v16 05/22] KVM: Rename CONFIG_KVM_GENERIC_PRIVATE_MEM to CONFIG_HAVE_KVM_ARCH_GMEM_POPULATE

[Sean Christopherson <seanjc@google.com>]

On Wed, Jul 23, 2025, Xiaoyao Li wrote:
> On 7/23/2025 6:46 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.
> > 
> > The new name, HAVE_KVM_ARCH_GMEM_POPULATE, describes the purpose of the
> > option: to enable arch-specific guest_memfd population mechanisms. It
> > also follows the same pattern as the other HAVE_KVM_ARCH_* configuration
> > options.
> > 
> > This improves clarity for developers and ensures the name accurately
> > reflects the functionality it controls, especially as guest_memfd
> > support expands beyond purely "private" memory scenarios.
> > 
> > Note that the vm type KVM_X86_SW_PROTECTED_VM does not need the populate
> > function. Therefore, ensure that the correct configuration is selected
> > when KVM_SW_PROTECTED_VM is enabled.
> 
> the changelog needs to be enhanced. At least it doesn't talk about
> KVM_X86_PRIVATE_MEM at all.
> 
> If Sean is going to queue this version, I think he can help refine it when
> queuing.

My bad, I simply forgot.  How's this?

--

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.

The new name, HAVE_KVM_ARCH_GMEM_POPULATE, describes the purpose of the
option: to enable arch-specific guest_memfd population mechanisms. It
also follows the same pattern as the other HAVE_KVM_ARCH_* configuration
options.

This improves clarity for developers and ensures the name accurately
reflects the functionality it controls, especially as guest_memfd
support expands beyond purely "private" memory scenarios.

Temporarily keep KVM_GENERIC_PRIVATE_MEM as an x86-only config so as to
minimize the churn, and to hopefully make it easier to see what features
require HAVE_KVM_ARCH_GMEM_POPULATE.  On that note, omit GMEM_POPULATE
for KVM_X86_SW_PROTECTED_VM, as regular ol' memset() suffices for
software-protected VMs.

As for KVM_GENERIC_PRIVATE_MEM, a future change will select KVM_GUEST_MEMFD
for all 64-bit KVM builds, at which point the intermedidate config will
become obsolete and can/will be dropped.