commit 00c0911c68e5bd664de1a261b74c390f4c0be83d
author Xiaoyao Li <xiaoyao.li@intel.com> Mon Jul 28 19:57:07 2025 +0800
committer Paolo Bonzini <pbonzini@redhat.com> Wed Sep 17 19:01:57 2025 +0200
tree 64c622cfe588118c7cadb74709162e06836873bd
parent 80030f66ad15c1534f5e3700b0acefd6d0d92e37

accel/kvm: Set guest_memfd_offset to non-zero value only when guest_memfd is valid

Current QEMU unconditionally sets the guest_memfd_offset of KVMSlot in
kvm_set_phys_mem(), which leads to the trace of kvm_set_user_memory looks:

kvm_set_user_memory AddrSpace#0 Slot#4 flags=0x2 gpa=0xe0000 size=0x20000 ua=0x7f5840de0000 guest_memfd=-1 guest_memfd_offset=0x3e0000 ret=0

It's confusing that the guest_memfd_offset has a non-zero value while
the guest_memfd is invalid (-1).

Change to only set guest_memfd_offset when guest_memfd is valid and
leave it as 0 when no valid guest_memfd.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20250728115707.1374614-4-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>