Re: [PATCH v10 07/41] KVM: guest_memfd: Stub in ability to enable in-place shared<=>private conversion

On 8/7/26 23:52, Ackerley Tng via B4 Relay wrote:
> From: Sean Christopherson <[email protected]>
> 
> Stub in global variable to enable in-place guest_memfd private<=>shared
> memory conversion, which will eventually be exposed to userspace via a
> module param, and wire up the __kvm_mem_is_private() static call to the
> guest_memfd version when in-place conversion is enabled, i.e. when gmem is
> the sole authority on private vs. shared memory.
> 
> Cc: Fuad Tabba <[email protected]>
> Cc: Xiaoyao Li <[email protected]>
> Signed-off-by: Sean Christopherson <[email protected]>
> Co-developed-by: Ackerley Tng <[email protected]>
> Signed-off-by: Ackerley Tng <[email protected]>
> ---
>  include/linux/kvm_host.h |  6 ++++++
>  virt/kvm/guest_memfd.c   | 26 ++++++++++++++++++++++++++
>  virt/kvm/kvm_main.c      | 12 +++++++++++-
>  3 files changed, 43 insertions(+), 1 deletion(-)
> 
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 65fbce46b63f4..9477ecebbbced 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -2580,6 +2580,8 @@ static inline bool kvm_vm_mem_is_private(struct kvm *kvm, gfn_t gfn)
>  #endif  /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */
>  
>  #ifdef kvm_arch_has_private_mem
> +extern bool gmem_in_place_conversion;

Is there a "supports/has/enable" in there? And should we call it "kvm_gmem" for
completeness?


> +
>  typedef bool (kvm_mem_is_private_t)(struct kvm *kvm, gfn_t gfn);
>  DECLARE_STATIC_CALL(__kvm_mem_is_private, kvm_mem_is_private_t);
>  
> @@ -2588,6 +2590,8 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
>  	return static_call(__kvm_mem_is_private)(kvm, gfn);
>  }
>  #else
> +#define gmem_in_place_conversion false
> +
>  static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
>  {
>  	return false;
> @@ -2595,6 +2599,8 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
>  #endif /* kvm_arch_has_private_mem */
>  
>  #ifdef CONFIG_KVM_GUEST_MEMFD
> +bool kvm_gmem_is_private(struct kvm *kvm, gfn_t gfn);

As mentioned in v9, the name is confusing.

	kvm_gmem_mem_is_private

?


-- 
Cheers,

David