Re: [PATCH v13 16/35] KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory

[Xiaoyao Li]

On 10/28/2023 2:21 AM, Sean Christopherson wrote:
...

+KVM_SET_USER_MEMORY_REGION2 is an extension to KVM_SET_USER_MEMORY_REGION that
+allows mapping guest_memfd memory into a guest.  All fields shared with
+KVM_SET_USER_MEMORY_REGION identically.  Userspace can set KVM_MEM_PRIVATE in
+flags to have KVM bind the memory region to a given guest_memfd range of
+[guest_memfd_offset, guest_memfd_offset + memory_size].  The target guest_memfd
+must point at a file created via KVM_CREATE_GUEST_MEMFD on the current VM, and
+the target range must not be bound to any other memory region.  All standard
+bounds checks apply (use common sense).
+
  ::

struct kvm_userspace_memory_region2 {

@@ -6087,9 +6096,24 @@ applied.
        __u64 guest_phys_addr;
        __u64 memory_size; /* bytes */
        __u64 userspace_addr; /* start of the userspace allocated memory */
+  __u64 guest_memfd_offset;

missing a tab

+       __u32 guest_memfd;
+       __u32 pad1;
+       __u64 pad2[14];
    };