[PATCH v9 08/41] KVM: Consolidate private memory and guest_memfd ifdeffery in kvm_host.h

From: Ackerley Tng via B4 Relay

Date: Tue Jul 28 2026 - 20:47:50 EST


From: Sean Christopherson <seanjc@xxxxxxxxxx>

Move the kvm_arch_has_private_mem() stub and a few guest_memfd function
definitions/declarations "down" in kvm_host.h to utilize existing #ifdefs,
and so that related code is clustered together.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Reviewed-by: Fuad Tabba <tabba@xxxxxxxxxx>
Tested-by: Shivank Garg <shivankg@xxxxxxx>
Signed-off-by: Ackerley Tng <ackerleytng@xxxxxxxxxx>
---
include/linux/kvm_host.h | 37 ++++++++++++++++---------------------
1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a913dd57ae622..f408746d315f7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -722,27 +722,6 @@ static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
}
#endif

-#ifndef kvm_arch_has_private_mem
-static inline bool kvm_arch_has_private_mem(struct kvm *kvm)
-{
- return false;
-}
-#endif
-
-#ifdef CONFIG_KVM_GUEST_MEMFD
-bool kvm_arch_supports_gmem_init_shared(struct kvm *kvm);
-
-static inline u64 kvm_gmem_get_supported_flags(struct kvm *kvm)
-{
- u64 flags = GUEST_MEMFD_FLAG_MMAP;
-
- if (!kvm || kvm_arch_supports_gmem_init_shared(kvm))
- flags |= GUEST_MEMFD_FLAG_INIT_SHARED;
-
- return flags;
-}
-#endif
-
#ifndef kvm_arch_has_readonly_mem
static inline bool kvm_arch_has_readonly_mem(struct kvm *kvm)
{
@@ -2591,6 +2570,11 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
#else
#define gmem_in_place_conversion false

+static inline bool kvm_arch_has_private_mem(struct kvm *kvm)
+{
+ return false;
+}
+
static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
{
return false;
@@ -2599,6 +2583,17 @@ static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)

#ifdef CONFIG_KVM_GUEST_MEMFD
bool kvm_gmem_is_private(struct kvm *kvm, gfn_t gfn);
+bool kvm_arch_supports_gmem_init_shared(struct kvm *kvm);
+
+static inline u64 kvm_gmem_get_supported_flags(struct kvm *kvm)
+{
+ u64 flags = GUEST_MEMFD_FLAG_MMAP;
+
+ if (!kvm || kvm_arch_supports_gmem_init_shared(kvm))
+ flags |= GUEST_MEMFD_FLAG_INIT_SHARED;
+
+ return flags;
+}

int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot,
gfn_t gfn, kvm_pfn_t *pfn, struct page **page,

--
2.55.0.508.g3f0d502094-goog