diff mbox series

[RFC,v2,05/11] KVM: guest_memfd: Handle in-place shared memory as guest_memfd backed memory

Message ID 20250129172320.950523-6-tabba@google.com
State New
Headers show
Series [RFC,v2,01/11] mm: Consolidate freeing of typed folios on final folio_put() | expand

Commit Message

Fuad Tabba Jan. 29, 2025, 5:23 p.m. UTC 
For VMs that allow sharing guest_memfd backed memory in-place,
handle that memory the same as "private" guest_memfd memory. This
means that faulting that memory in the host or in the guest will
go through the guest_memfd subsystem.

Note that the word "private" in the name of the function
kvm_mem_is_private() doesn't necessarily indicate that the memory
isn't shared, but is due to the history and evolution of
guest_memfd and the various names it has received. In effect,
this function is used to multiplex between the path of a normal
page fault and the path of a guest_memfd backed page fault.

Signed-off-by: Fuad Tabba <tabba@google.com>
---
 include/linux/kvm_host.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 408429f13bf4..e57cdf4e3f3f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2503,7 +2503,8 @@  static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
 #else
 static inline bool kvm_mem_is_private(struct kvm *kvm, gfn_t gfn)
 {
-	return false;
+	return kvm_arch_gmem_supports_shared_mem(kvm) &&
+	       kvm_slot_can_be_private(gfn_to_memslot(kvm, gfn));
 }
 #endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */