It looks like de Gournay! Which is £££££££however if you go on Etsy and search chionoiserie wallpaper, you can get it custom designed for MUCH cheaper.
Theres also a great US website called Spoonflower where designers upload their prints and you can have them made into fabric/wallpaper/duvet cover/tea towels. It's a brilliant site but the import charges are a bitch.