"Kalyazin, Nikita" <[email protected]> writes: > From: Patrick Roy <[email protected]> > > Have vm_mem_add() always set KVM_MEM_GUEST_MEMFD in the memslot flags if > a guest_memfd is passed in as an argument. This eliminates the > possibility where a guest_memfd instance is passed to vm_mem_add(), but > it ends up being ignored because the flags argument does not specify > KVM_MEM_GUEST_MEMFD at the same time. > > This makes it easy to support more scenarios in which no vm_mem_add() is > not passed a guest_memfd instance, but is expected to allocate one. > Currently, this only happens if guest_memfd == -1 but flags & > KVM_MEM_GUEST_MEMFD != 0, but later vm_mem_add() will gain support for > loading the test code itself into guest_memfd (via > GUEST_MEMFD_FLAG_MMAP) if requested via a special > vm_mem_backing_src_type, at which point having to make sure the src_type > and flags are in-sync becomes cumbersome. > > Signed-off-by: Patrick Roy <[email protected]> > Signed-off-by: Nikita Kalyazin <[email protected]> > --- > tools/testing/selftests/kvm/lib/kvm_util.c | 24 +++++++++++++--------- > 1 file changed, 14 insertions(+), 10 deletions(-) > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c > b/tools/testing/selftests/kvm/lib/kvm_util.c > index 8279b6ced8d2..56ddbca91850 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -1057,21 +1057,25 @@ void vm_mem_add(struct kvm_vm *vm, enum > vm_mem_backing_src_type src_type, > > region->backing_src_type = src_type; > > - if (flags & KVM_MEM_GUEST_MEMFD) { > - if (guest_memfd < 0) { > + if (guest_memfd < 0) { > + if (flags & KVM_MEM_GUEST_MEMFD) { > uint32_t guest_memfd_flags = 0; > TEST_ASSERT(!guest_memfd_offset, > "Offset must be zero when creating new > guest_memfd"); > guest_memfd = vm_create_guest_memfd(vm, mem_size, > guest_memfd_flags); > - } else { > - /* > - * Install a unique fd for each memslot so that the fd > - * can be closed when the region is deleted without > - * needing to track if the fd is owned by the framework > - * or by the caller. > - */ > - guest_memfd = kvm_dup(guest_memfd); > } > + } else { > + /* > + * Install a unique fd for each memslot so that the fd > + * can be closed when the region is deleted without > + * needing to track if the fd is owned by the framework > + * or by the caller. > + */ > + guest_memfd = kvm_dup(guest_memfd); > + } > + > + if (guest_memfd > 0) {
Might 0 turn out to be a valid return from dup() for a guest_memfd? > + flags |= KVM_MEM_GUEST_MEMFD; > > region->region.guest_memfd = guest_memfd; > region->region.guest_memfd_offset = guest_memfd_offset; Refactoring vm_mem_add() (/* FIXME: This thing needs to be ripped apart and rewritten. */) should probably be a separate patch series, but I'd like to take this opportunity to ask: Sean, what do you have in mind for the rewritten version? Would it be something like struct vm_shape, where there are default mem_shapes, and the shapes get validated and then passed to vm_mem_add()? > -- > 2.50.1
