On Thu, Oct 10, 2019 at 02:11:46PM +0200, Auger Eric wrote: > >>> Also, should we avoid using UINT in all cases? But of course if we > >>> start to use VMSTATE_UINT32_V then we don't have this issue. > >> Depending on the clarification of above point, maybe I can rename > >> VMSTATE_GTREE_DIRECT_KEY_V into VMSTATE_GTREE_DIRECT_UINT_KEY_V > >> > >> direct keys seem to be more common for hash tables actually. > >> https://developer.gnome.org/glib/stable/glib-Hash-Tables.html#g-hash-table-new-full > >> > >> There are stand conversion macros to/from int, uint, size > >> https://developer.gnome.org/glib/stable/glib-Type-Conversion-Macros.html > > > > Yeh it's fine to use direct keys. Though my question was more about > > "unsigned int" - here when we put, we cast a pointer into unsigned > > int, which can be 2/4 bytes, IIUC. I'm thinking whether at least we > > should use direct cast (e.g., (uint32_t)ptr) to replace > > GPOINTER_TO_UINT() to make sure it's 4 bytes. Futher, maybe we should > > start with uint64_t here in the migration stream, otherwise we should > > probably drop the high 32 bits if we migrate a gtree whose key is 64 > > bits long (and since we're working with migration we won't be able to > > change that in the future for compatibility reasons...). > > > > Summary: > > > > Maybe we can replace: > > > > qemu_put_be32(f, GPOINTER_TO_UINT(key)); /* direct key */ > > > > To: > > > > qemu_put_be64(f, (uint64_t)key); /* direct key */ > > > > And apply similar thing to get() side? > > This was my first idea as well but I got stuck with a mingw compilation > issues if I remember correctly, trying to cast pointers to a wrong sized > uint. This got removed by using the GPOINTER_TO_UINT conversion functions.
#define GPOINTER_TO_UINT(p) ((guint) (gulong) (p)) Could "(uint64_t)(uintptr_t)pointer" do the work? Thanks, -- Peter Xu