On 6/19/2026 8:31 AM, Ackerley Tng via B4 Relay wrote:
From: Ackerley Tng <[email protected]>
Explicitly guard reporting support for KVM_MEMORY_ATTRIBUTE_PRIVATE based
on kvm_arch_has_private_mem being #defined in anticipation of decoupling
kvm_supported_mem_attributes() from CONFIG_KVM_VM_MEMORY_ATTRIBUTES.
Well, after this series, kvm_supported_mem_attributes() is renamed to
kvm_supported_vm_mem_attributes(), and it's still under
CONFIG_KVM_VM_MEMORY_ATTRIBUTES.
guest_memfd support for memory attributes will be unconditional to avoid
yet more macros (all architectures that support guest_memfd are expected to
use per-gmem attributes at some point), at which point enumerating support
KVM_MEMORY_ATTRIBUTE_PRIVATE based solely on memory attributes being
supported _somewhere_ would result in KVM over-reporting support on arm64.
I don't understand it. This patch only changes the behavior of
kvm_supported_mem_attributes(), the usage of which is guarded by
CONFIG_KVM_VM_MEMORY_ATTRIBUTES. This is config is only visible to x86
due to patch 03. How does it affect arm64?
Signed-off-by: Sean Christopherson <[email protected]>
Reviewed-by: Fuad Tabba <[email protected]>
Signed-off-by: Ackerley Tng <[email protected]>
---
virt/kvm/kvm_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1ccc4895a4c26..7b989b659cf82 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2421,8 +2421,10 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES
static u64 kvm_supported_mem_attributes(struct kvm *kvm)
{
+#ifdef kvm_arch_has_private_mem
if (!kvm || kvm_arch_has_private_mem(kvm))
return KVM_MEMORY_ATTRIBUTE_PRIVATE;
+#endif
return 0;
}
