On 19/06/2026 09:21, Fuad Tabba wrote:

On Fri, 19 Jun 2026 at 09:19, Fuad Tabba [off-list ref] wrote:

quoted

On Fri, 19 Jun 2026 at 01:31, Ackerley Tng via B4 Relay
[off-list ref] wrote:

quoted

From: Sean Christopherson <seanjc@google.com>

Introduce a generic kvm_mem_is_private() interface using a static call to
determine if a GFN is private. This allows the implementation for checking
a GFN's private/shared status to be set at runtime.

In preparation for choosing implementations between a guest_memfd lookup
and the existing VM attribute lookup, rename the existing
VM-attribute-based check to kvm_vm_mem_is_private to emphasize that it
looks up VM attributes.

Signed-off-by: Sean Christopherson <seanjc@google.com>

(SoB fix plz)

Reviewed-by: Fuad Tabba <tabba@google.com>

Cheers,
/fuad

quoted

---
  include/linux/kvm_host.h | 12 +++++++++++-
  virt/kvm/kvm_main.c      | 15 +++++++++++++++
  2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index eb26d4ea8945a..3915da2a61778 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h

@@ -2546,7 +2546,7 @@ bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
  bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,
                                          struct kvm_gfn_range *range);

-static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
+static inline bool kvm_vm_mem_is_private(struct kvm *kvm, gfn_t gfn)

Should have read the Sashiko review first, but where is this used?
It's not used at all in this series...

See below:

/fuad

quoted

quoted

  {
         return kvm_get_vm_memory_attributes(kvm, gfn) & KVM_MEMORY_ATTRIBUTE_PRIVATE;
  }

@@ -2557,6 +2557,16 @@ static inline bool kvm_mem_range_is_private(struct kvm *kvm, gfn_t start,
                                                   KVM_MEMORY_ATTRIBUTE_PRIVATE,
                                                   KVM_MEMORY_ATTRIBUTE_PRIVATE);
  }
+#endif  /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */
+
+#ifdef kvm_arch_has_private_mem
+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);
+
+static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
+{
+       return static_call(__kvm_mem_is_private)(kvm, gfn);
+}
  #else
  static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
  {

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 6669f1477013c..8b238e461b854 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c

@@ -2627,6 +2627,20 @@ static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm,
  }
  #endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */

+#ifdef kvm_arch_has_private_mem
+DEFINE_STATIC_CALL_RET0(__kvm_mem_is_private, kvm_mem_is_private_t);
+EXPORT_STATIC_CALL_GPL(__kvm_mem_is_private);
+
+static void kvm_init_memory_attributes(void)
+{
+#ifdef CONFIG_KVM_VM_MEMORY_ATTRIBUTES
+       static_call_update(__kvm_mem_is_private, kvm_vm_mem_is_private);
+#endif
+}

Here ^^ as the static call update ?


Suzuki