Re: [PATCH v8 03/46] KVM: Move KVM_VM_MEMORY_ATTRIBUTES config definition to x86

[Binbin Wu]

On 6/19/2026 8:31 AM, Ackerley Tng via B4 Relay wrote:
> From: Sean Christopherson <seanjc@xxxxxxxxxx>
> 
> Bury KVM_VM_MEMORY_ATTRIBUTES in x86 to discourage other architectures
> from adding support for per-VM memory attributes, because tracking private
> vs. shared memory on a per-VM basis is now deprecated in favor of tracking
> on a per-guest_memfd basis, and while RWX memory attributes are on the
> horizon, they too are expected to be x86-only.
> 
> This will also allow modifying KVM_VM_MEMORY_ATTRIBUTES to be
> user-selectable (in x86) without creating weirdness in KVM's Kconfigs.
> Now that guest_memfd supports in-place conversions, it's entirely possible
> to run x86 CoCo VMs without support for KVM_VM_MEMORY_ATTRIBUTES.
> 
> Leave the code itself in common KVM so that it's trivial to undo this
> change if new per-VM attributes do come along.
> 
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Reviewed-by: Fuad Tabba <tabba@xxxxxxxxxx>
> Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>

Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>

> ---
>  arch/x86/kvm/Kconfig | 3 +++
>  virt/kvm/Kconfig     | 3 ---
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
> index 26f6afd51bbdc..24f96396cfa1c 100644
> --- a/arch/x86/kvm/Kconfig
> +++ b/arch/x86/kvm/Kconfig
> @@ -80,6 +80,9 @@ config KVM_WERROR
>  
>  	  If in doubt, say "N".
>  
> +config KVM_VM_MEMORY_ATTRIBUTES
> +	bool
> +
>  config KVM_SW_PROTECTED_VM
>  	bool "Enable support for KVM software-protected VMs"
>  	depends on EXPERT
> diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
> index 5119cb37145fc..297e4399fbd49 100644
> --- a/virt/kvm/Kconfig
> +++ b/virt/kvm/Kconfig
> @@ -100,9 +100,6 @@ config KVM_ELIDE_TLB_FLUSH_IF_YOUNG
>  config KVM_MMU_LOCKLESS_AGING
>         bool
>  
> -config KVM_VM_MEMORY_ATTRIBUTES
> -       bool
> -
>  config KVM_GUEST_MEMFD
>         select XARRAY_MULTI
>         bool
>