* Michael S. Tsirkin (m...@redhat.com) wrote: > On Thu, Jan 18, 2018 at 07:59:35PM +0000, Dr. David Alan Gilbert wrote: > > * Michael S. Tsirkin (m...@redhat.com) wrote: > > > On Tue, Jan 16, 2018 at 06:04:01PM +0000, Dr. David Alan Gilbert (git) > > > wrote: > > > > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> > > > > > > > > Hi, > > > > This patch set reworks the way the vhost code handles changes in > > > > physical address space layout that came from a discussion with Igor. > > > > > > > > Its intention is to simplify a lot of the update code, > > > > and to make it easier for the postcopy+shared code to > > > > do the hugepage alignments that are needed. > > > > > > > > Instead of inserting/removing each section during the add/del > > > > callbacks of the listener, we start afresh and build a list > > > > from the add and nop callbacks, then at the end compare the list > > > > we've built with the exisiting list. > > > > > > > > v6 > > > > Tidy ups from Igor > > > > The biggest change is moving the 'Move log_dirty check' to be > > > > the last patch in the set. > > > > > > > > Dr. David Alan Gilbert (7): > > > > vhost: Build temporary section list and deref after commit > > > > vhost: Simplify ring verification checks > > > > vhost: Merge sections added to temporary list > > > > vhost: Regenerate region list from changed sections list > > > > vhost: Clean out old vhost_set_memory and friends > > > > vhost: Merge and delete unused callbacks > > > > vhost: Move log_dirty check > > > > > > > > hw/virtio/trace-events | 6 + > > > > hw/virtio/vhost.c | 497 > > > > ++++++++++++++++------------------------------ > > > > include/hw/virtio/vhost.h | 5 +- > > > > 3 files changed, 180 insertions(+), 328 deletions(-) > > > > > > > > > Seems to trigger errors with clang runtime sanitizer: > > > > > > /scm/qemu/hw/virtio/vhost.c:425:26: runtime error: null pointer passed as > > > argument 1, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:45: runtime error: null pointer passed as > > > argument 2, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:26: runtime error: null pointer passed as > > > argument 1, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:45: runtime error: null pointer passed as > > > argument 2, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:26: runtime error: null pointer passed as > > > argument 1, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:45: runtime error: null pointer passed as > > > argument 2, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:26: runtime error: null pointer passed as > > > argument 1, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > /scm/qemu/hw/virtio/vhost.c:425:45: runtime error: null pointer passed as > > > argument 2, which is declared to never be null > > > /usr/include/string.h:64:33: note: nonnull attribute specified here > > > > > > How are you running that test? > > One Fedora: > dnf install clang > > '/scm/qemu-clang/../qemu/configure' '--cc=clang' '--cxx=clang++' > '--extra-cflags=-fsanitize=undefined -ferror-limit=10000 > -fno-sanitize=shift-base' > make > make check.
Thanks. > > Can you add this printf and tell me what > > it's seeing? > > > > /* Same size, lets check the contents */ > > fprintf(stderr, "%s: %p %p %d\n", __func__, dev->mem_sections, > > old_sections, n_old_sections); > > changed = memcmp(dev->mem_sections, old_sections, > > n_old_sections * sizeof(old_sections[0])) != 0; > > > > I'm seeing a bunch of calls where both pointers are NULL, but > > n_old_sections is 0, which feels legal to me. > > https://stackoverflow.com/questions/16362925/can-i-pass-a-null-pointer-to-memcmp > > says it's invalid. Posted v7 with trivial fix for it. (It seems rather ungenerous of the standard to be fussy about that). Dave > > I guess we could make it: > > changed = n_old_sections ? memcmp(....) : false; > > just to shut clang up. > > > > Dave > > > > > > > > > > > > -- > > > > 2.14.3 > > -- > > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
