KVM: x86/mmu: Set shadow_accessed_mask for EPT even if A/D bits disabled

Now that KVM doesn't use shadow_accessed_mask to detect if hardware A/D
bits are enabled, set shadow_accessed_mask for EPT even when A/D bits
are disabled in hardware.  This will allow using shadow_accessed_mask for
software purposes, e.g. to preserve accessed status in a non-present SPTE
acros NUMA balancing, if something like that is ever desirable.

Link: https://lore.kernel.org/r/20241011021051.1557902-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

Author: sean-jc

arch/x86/kvm/mmu/spte.c

@@ -419,7 +419,7 @@ void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only)
 	kvm_ad_enabled		= has_ad_bits;
 
 	shadow_user_mask	= VMX_EPT_READABLE_MASK;
-	shadow_accessed_mask	= has_ad_bits ? VMX_EPT_ACCESS_BIT : 0ull;
+	shadow_accessed_mask	= VMX_EPT_ACCESS_BIT;
 	shadow_dirty_mask	= has_ad_bits ? VMX_EPT_DIRTY_BIT : 0ull;
 	shadow_nx_mask		= 0ull;
 	shadow_x_mask		= VMX_EPT_EXECUTABLE_MASK;