From ee1168fb73136dc1bd6b6f26142fdaa2399a2d60 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Sep 2026 16:55:35 -0700 Subject: KVM: guest_memfd: Stub in ability to enable in-place shared<=>private conversion Stub in global variable to enable in-place guest_memfd private<=>shared memory conversion, which will eventually be exposed to userspace via a module param, and wire up the __kvm_is_private_gfn() static call to the guest_memfd version when in-place conversion is enabled, i.e. when gmem is the sole authority on private vs. shared memory. Co-developed-by: Ackerley Tng Signed-off-by: Ackerley Tng Reviewed-by: Fuad Tabba Reviewed-by: Binbin Wu Reviewed-by: David Hildenbrand (Arm) Cc: Fuad Tabba Cc: Xiaoyao Li Tested-by: Yan Zhao Link: https://patch.msgid.link/20260910-gmem-inplace-conversion-v13-9-dd6fbf94f4e1@google.com Signed-off-by: Sean Christopherson --- include/linux/kvm_host.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3579feb63177..b0110143d2ff 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2580,6 +2580,8 @@ static inline bool kvm_vm_is_private_gfn(struct kvm *kvm, gfn_t gfn) #endif /* CONFIG_KVM_VM_MEMORY_ATTRIBUTES */ #ifdef kvm_arch_has_private_mem +extern bool gmem_in_place_conversion; + typedef bool (kvm_is_private_gfn_t)(struct kvm *kvm, gfn_t gfn); DECLARE_STATIC_CALL(__kvm_is_private_gfn, kvm_is_private_gfn_t); @@ -2588,6 +2590,8 @@ static inline bool kvm_is_private_gfn(struct kvm *kvm, gfn_t gfn) return static_call(__kvm_is_private_gfn)(kvm, gfn); } #else +#define gmem_in_place_conversion false + static inline bool kvm_is_private_gfn(struct kvm *kvm, gfn_t gfn) { return false; @@ -2595,6 +2599,8 @@ static inline bool kvm_is_private_gfn(struct kvm *kvm, gfn_t gfn) #endif /* kvm_arch_has_private_mem */ #ifdef CONFIG_KVM_GUEST_MEMFD +bool kvm_gmem_is_private_gfn(struct kvm *kvm, gfn_t gfn); + int kvm_gmem_get_pfn(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn, kvm_pfn_t *pfn, int *max_order); #else -- cgit v1.2.3