[PATCH v9 19/41] KVM: Move KVM_VM_MEMORY_ATTRIBUTES config definition to x86

[Ackerley Tng via B4 Relay]

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>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Tested-by: Shivank Garg <shivankg@xxxxxxx>
Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
---
 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 2f8e1b5a8a72c..abb108886733a 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 df575449d97b5..a0678ef8ee3f5 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

-- 
2.55.0.508.g3f0d502094-goog